Scientists Develop New, Faster Method for Seeking out Dark Matter P

LIGHT + MATTER Spring/Summer 2021 | jila.colorado.edu

Scientists Develop New, Faster Method for Seeking out Dark Matter p. 1 Furry friend enjoying the springtime snow! Image Credit: Kristin Conrad

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Steven Burrows, Project Manager, Artwork Molly Alvine, Design & Production Kenna Castleberry, Science Writing Gwen Dickinson, Editor Stories Scientists Develop New, Faster Method for Seeking Out Dark Matter 1

The Forces Involved in Folding Proteins 4

Using Quantum Knots to Build a Secure Internet 7

NIST Team Compares 3 Top Atomic Clocks with Record Accuracy 9

Scientists Dig Deeper into Subject of First-Ever Image of a Black Hole 11

Molecules in Flat Lands: An Entanglement Paradise 13 Feature Articles

Highlighting the Research Centers within JILA 15

David Jacobson is Awarded the 2021 NIH Pathway to Independence Award 18

Life after JILA 19

Heather Lewandowski Wins the 2021 Boulder Faculty Excellence Award 20 Scientists Develop New, Faster Method for Seeking Out Dark Matter

or nearly a century, scientists their hunt past a fundamental ob- HAYSTAC is led by Yale and is a Fhave worked to unravel the stacle imposed by the laws of ther- partnership with JILA and the Uni- mystery of dark matter—an elusive modynamics. The group includes versity of California, Berkeley. substance that spreads through scientists at JILA, a joint research the universe and likely makes up institute of the University of Colora- Quantum laws much of its mass, but has so far do Boulder and the National Insti- proven impossible to detect in tute of Standards and Technology Daniel Palken, the co-first author experiments. Now, a team of re- (NIST). of the new paper, explained that searchers has used an innova- what makes the axion so difficult to tive technique called “quantum “It’s a doubling of the speed from find is also what makes it such an squeezing” to dramatically speed what we were able to do before,” ideal candidate for dark matter— up the search for one candidate for said Kelly Backes, one of two lead it’s lightweight, carries no electric dark matter in the lab. authors of the new paper and a charge and almost never interacts graduate student at Yale Universi- with normal matter. The findings, published 10 Feb- ty. ruary 2021 in the journal Nature, “They don’t have any of the prop- center on an incredibly lightweight The new approach allows research- erties that make a particle easy to and as-of-yet undiscovered parti- ers to better separate the incredi- detect,” said Palken, who earned cle called the axion. According to bly faint signals of possible axions his PhD from JILA in 2020 theory, axions are likely billions to from the random noise that exists trillions of times smaller than elec- at extremely small scales in na- But there’s one silver lining: If ax- trons and may have been created ture, sometimes called “quantum ions pass through a strong enough during the Big Bang in humungous fluctuations.” The team’s chances magnetic field, a small number of numbers—enough to potentially ex- of finding the axion over the next them may transform into waves of plain the existence of dark matter. several years are still about as like- light—and that’s something that ly as winning the lottery, said study scientists can detect. Researchers Finding this promising particle, coauthor Konrad Lehnert, a NIST have launched efforts to find those however, is a bit like looking for a Fellow at JILA. But those odds are signals in powerful magnetic fields single quantum needle in one real- only going to get better. in space. The HAYSTAC experiment, ly big haystack. however, is keeping its feet planted “Once you have a way around on Earth. There may be some relief in sight. quantum fluctuations, your path Researchers on a project called, can just be made better and bet- The project, which published its fittingly, the Haloscope At Yale Sen- ter,” said Lehnert, also a professor first findings in 2017, employs an sitive To Axion Cold Dark Matter adjoint in the Department of Phys- ultra-cold facility on the Yale cam- (HAYSTAC) experiment report that ics at CU Boulder. pus to create strong magnetic they’ve improved the efficiency of fields, then try to detect the signal

1 Spring/Summer 2021 ◊ JILA Light & Matter An artistic rendition of the HAYSTAC experiment. Image Credit: The Lehnert Group, Steven Burrows, JILA

1 Spring/Summer 2021 ◊ JILA Light & Matter of axions turning into light. It’s not tool called a Josephson paramet- “Squeezing is just our way of ma- an easy search. Scientists have ric amplifier. Scientists at JILA de- nipulating the quantum mechan- predicted that axions could exhibit veloped a way to use these small ical vacuum to put ourselves in a an extremely wide range of theoret- devices to “squeeze” the light they position to measure one variable ical masses, each of which very well,” Palken said. “If would produce a signal at a we tried to measure the different frequency of light other variable, we would in an experiment like HAY- find we would have very lit- STAC. In order to find the tle precision.” real particle, then, the team may have to rifle through To test out the method, the a large range of possibili- researchers did a trial run ties—like tuning a radio to at Yale to look for the par- find a single, faint station. ticle over a certain range of masses. They didn’t find “If you’re trying to drill down it, but the experiment took to these really feeble sig- half the time that it usually nals, it could end up taking would, Backes said. you thousands of years,” Palken said. “We did a 100-day data run,” she said. “Normally, Some of the biggest obsta- this paper would have tak- cles facing the team are the en us 200 days to com- laws of quantum mechan- plete, so we saved a third ics themselves—namely, of a year, which is pretty the Heisenberg Uncertainty Experimental electronics in the dilu- incredible.” Principle, which limits how tion refrigerator. These components accurate scientists can ensure that quantum noise dominates Lehnert added that the the experiment. be in their observations of Image Credit: Kelly Backes, Yale University group is eager to push those particles. In this case, the bounds even farther—com- team can’t accurately mea- ing up with new ways to dig sure two different properties of were getting from the HAYSTAC ex- for that ever-elusive needle. the light produced by axions at the periment. same time. “There’s a lot of meat left on the Palken explained that the HAYSTAC bone in just making the idea work The HAYSTAC team, however, has team doesn’t need to detect both better,” he said. landed on a way to slip past those properties of incoming light waves immutable laws. with precision—just one of them. Written by Daniel Strain Squeezing takes advantage of that Shifting uncertainties by shifting uncertainties in mea- Backes, K.M., Palken, D.A., Kenany, S.A. et al. A quantum enhanced search for dark matter surements from one of those vari- axions. Nature 590, 238–242 (2021). The trick comes down to using a ables to another.

3 Spring/Summer 2021 ◊ JILA Light & Matter Spring/Summer 2021 ◊ JILA Light & Matter 4 The Forces Involved in Folding Proteins

Model of the type III secretion system in Salmonella bacteria Image Credit: The Perkins Lab, Steven Burrows, JILA

ashing your hands after physicist Thomas Perkins collabo- monella bacteria. Wcracking an egg or touching rated with CU Biochemistry profes- raw chicken may seem like com- sor Marcello Sousa to dissect the The type III secretion system is mon sense, as the possible result- mechanisms of how certain bac- shaped like a syringe, with a nee- ing bacterial infections have been teria become more virulent. The dle that’s only two nanometers in thoroughly studied. Yet, research- research brings together the Per- diameter (for reference, an atom ers at JILA have found something kins lab expertise in single-mol- is around 0.1 to 0.5 nanometers surprising and ground-breaking ecule studies and the Sousa lab in diameter). Through these nee- about the physics of bacterial expertise in the type III secretion dle-like structures, bacteria pump infections. In a new paper, JILA system, a key component of Sal- effector proteins directly into host

3 Spring/Summer 2021 ◊ JILA Light & Matter Spring/Summer 2021 ◊ JILA Light & Matter 4 cells, humans or livestock for ex- effector proteins have typical ther- governs whether a protein can ac- ample, to take control of various modynamic stabilities. Indeed, tually make it through the type III host cell functions, including sup- thermodynamic stabilities are in- secretion system.” Prior work by pressing the cell’s immune system distinguishable from proteins that others showed that proteins known or hijacking its DNA and RNA ma- clog the needle. The team then to clog the needle unfold at high chinery. In order for effector pro- looked to see if mechanical force force. Perkins goes on to say “If our teins to pass into the host cell, the might play a role hypothesis is correct, most, if not proteins must be partially unfolded all, effector proteins should unfold as the 2-nm pore is only a few at- Applying Force to Unfold at low force.” oms wide. Proteins Evolution and Unfolding Proteins that don’t unfold clog the The Perkins lab has lots of expe- Forces needle leading to the prevailing rience unfolding proteins using model that effector proteins have atomic force microscopy (AFM). From their data, the team realized low thermodynamic stability (and They developed modified cantile- that the mechanics of how these so are often unfolded) while pro- vers that have improved force pre- proteins unfold might shed light teins that clog the needle have cision and stability. Nonetheless, on another outstanding question high stability. it still took four years of effort to in the field. Proteins that have develop the ability to reliably apply the same structural fold and Protein folding and protein force to the two model effector pro- carry out the same function are stability teins (SptP and SopE2), larger and homologues. Homologues usu- more complicated proteins than ally have very similar protein se- Protein folding has been studied the model proteins the Perkins lab quences, the linear list of amino for decades. In general, proteins has studied in the past. The team acids that make up the protein. fold into their most stable state. needed to anchor the protein down However, protein sequences of Historically, protein stability is to a surface—without it randomly effector proteins have virtually no measured using thermodynamics. sticking—and then pull on it from similarity with homologues that According to JILA Fellow and ad- a specific point. After this develop- are not secreted. joint professor in Cellular, Molec- ment, they were finally able to look ular and Developmental biology, at the mechanics of effector pro- First author Marc-André LeBlanc Thomas Perkins, “The classic way tein unfolding. suggests that it is the evolutionary biochemists measure protein sta- pressures for these proteins to un- bility is either to increase tempera- Their data showed that the two fold at such low forces but main- ture or a denaturant, like urea, to model effector proteins were me- tain typical thermodynamic stabil- a high level and then lower it back chanically labile, meaning that they ities so they refold efficiently that down. If a protein unfolds and re- would easily unfold at low forces. causes their sequences to look so folds under these conditions, then Perkins said: “What is remarkable different. Perkins added. “Looking you can measure the thermody- is that these proteins unfold at very forward, one of the things we’re namic stability of the protein.” low forces compared to a peer set planning to investigate is if homo- of other proteins. That led us to the logues that don’t go through the When applying this technique to hypothesis that it is the mechani- type III secretion system are more effector proteins, the team found cal unfolding of these proteins that mechanically robust.”

5 Spring/Summer 2021 ◊ JILA Light & Matter sure for these effector proteins to and start to think about applica- diverge from their homologues in tions. There are some labs using the case of folding mechanics. the type III secretion system as a protein delivery mechanism. You This possible evolutionary pres- can certainly imagine if you have sure may provide insight into the a protein that you want to get into factors that control protein folding another cell, this might be a good and stability, which is what the Per- way to do it.” kins and Sousa Labs are currently studying by using AFM to investi- While the study is still in early de- gate targeted mutations in their velopment, the researchers are model effector proteins. excited to see the applications of their newly developed technologies Schematic depiction of The research is still ongoing. LeB- and the impacts of their work on protein transport through lanc is looking forward to using the the field of biophysics as a whole. the T3SS showing effec- newly developed technology to not tor proteins, which are at only expand the research, but give Marc-André LeBlanc, Morgan R. Fink, least partially folded in the Thomas T. Perkins, Marcelo C. Sousa. Type bacterial cytoplasm. the study possible medical appli- III secretion system effector proteins are Image Credit: The Perkins Lab cations. mechanically labile. Proceedings of the National Academy of Sciences 118 (12) e2019566118 (2021). If these non-secreted homologues “Everything is based on basic re- are more mechanically robust, then search at this point.” LeBlanc said. there was likely evolutionary pres- “But you can play that forward

5 Spring/Summer 2021 ◊ JILA Light & Matter Using Quantum Knots to Build a Secure Internet

n this era of the COVID-19 pan- Idemic, the amount of internet hacking has increased dramatically. Hackers threaten our security, taking information before anyone realizes the network has been compromised. These threats are serious and require creative and immediate action to resolve.

For scientists at JILA, a quantum internet is one way to resolve these actions. Essentially, a quantum internet connects different quantum computers or different quantum users into a network to achieve co- ordinated quantum tasks, explains Shuo Sun, a University of Colora- do Boulder Assistant Professor of Physics and JILA Associate Fellow. A quantum internet can enable secure communication, distributed quantum computing, and distributed sensing. In order for a quantum internet to work, it must be built using the principles of quantum mechanics. A quantum internet is a very broad concept and there are many fascinating things that researchers are looking into to use it. By entangling photons, scientists tie little quantum knots between them, so they jointly represent the information to be delivered. Photons and Encryption: Image Credit: The Sun Group, Steven Burrows, JILA

When looking within a quantum internet, the Sun Lab is looking spe- states at once. If a photon is like is observed; then it collapses into cifically at photons. Photons—tiny a computer bit (which is in binary either a 1 or 0 upon observation. packets of light—can exist in two code), it’s both a 1 and a 0 until it This quantum superposition of

7 Spring/Summer 2021 ◊ JILA Light & Matter Spring/Summer 2021 ◊ JILA Light & Matter 8 photons allows a receiver to know cles for encryption, as they can get vised a means of quickly tying the immediately if their message has lost by being absorbed by materi- quantum knots. The emitter sends been read by a hacker, once the al in fiber optic cables. When the a particle of light toward the mirror. photons’ superpositions collapse. photons get lost, their valuable in- It bounces off the mirror and pass- formation is lost as well. es back through the emitter, entan- And, thanks to quantum gling itself with the next particle of mechanics, scientists light. can’t just make copies of the information. According to Shuo Sun, the lab is planning to experimentally realize Entanglement and this photon generation scheme Quantum Knots: as an efficient way to encrypt information. They believe that their Instead, scientists can solid-state quantum emitter, com- use quantum mechan- bined with nanophotonics, offer a ics, specifically entan- very promising approach to real- glement, to protect the izing this scheme. “It is possible photons from being ab- to realize a source of multipartite sorbed. Entanglement entangled photons on a semi-con- connects quantum par- ductor chip” stated Sun. Overall, a ticles, stated Professor quantum internet allows us to con- Sun. By entangling these nect remote and isolated quantum photons, scientists tie systems into a larger system that little quantum knots can be more powerful. between them, so they jointly represent the in- The Sun Lab paper was published formation to be delivered. in Physics Review Letters on 24 The photons aren’t just November 2020. paired off within these quantum knots. They’re Yuan Zhan and Shuo Sun. Deterministic Generation of Loss-Tolerant Photonic Cluster connected to hundreds States with a Single Quantum Emitter. of other photons in a Physical Review Letters 125, 223601 (2020). tree-shaped pattern. The robust redundancy By entangling photons, scientists tie little quantum knots between them, so they jointly rep- of these photons means resent the information to be delivered. that scientists can still Image Credit: The Sun Group, Steven Burrows, JILA read the information, even if a few photons are lost.

There are some complications Using a mirror and a photon emit- within photons being used as vehi- ter, the Sun Lab at JILA has de-

Spring/Summer 2021 ◊ JILA Light & Matter 8 NIST Team Compares Three Top Atomic Clocks with Record Accuracy n a significant advance toward Ithe future redefinition of the international unit of time, the second, a research team led by the National Institute of Standards and Technol- ogy (NIST) has compared three of the world’s leading atomic clocks with record accuracy over both air and optical fiber links.

Described in the March 25 issue of Nature, the NIST-led work is the first to compare three clocks, each based on different atoms, and the first to link the most advanced Model of Atomic Clock Comparisons between JILA and NIST. atomic clocks in different locations Credit: N. Hanacek/NIST over the air. These atomic clock comparisons place the scientif- required cutting-edge laser tech- tium clocks, and found the process ic community one step closer to nology and design. worked as well as the fiber-based meeting the guidelines for redefini- method and 1,000 times more tion of the second. The study compared the alumi- precisely than conventional wire- num-ion clock and ytterbium opti- less transfer schemes. This work “These comparisons are really de- cal lattice clock, located in differ- shows how the best atomic clocks fining the state of the art for both ent laboratories at NIST Boulder, might be synchronized across re- fiber-based and free-space mea- with the strontium optical lattice mote sites on Earth and, as time surements—they are all close to clock located 1.5 kilometers away signals are transferred over longer 10 times more accurate than any at JILA, The team’s measurements distances, even between space- clock comparisons using different were so accurate that uncertain- craft. atoms performed so far,” NIST ties were only 6 to 8 parts in 1018— physicist David Hume said. that is, errors never exceeded The key to the air link was the use 0.000000000000000008—for of optical frequency combs, which The new measurements were chal- both fiber and wireless links. enable accurate comparisons of lenging because the three types widely different frequencies. NIST of atoms involved “tick” at vastly NIST researchers previously de- researchers developed two-way different frequencies, because all scribed in detail how they trans- transfer methods to precisely of the many network components ferred time signals over the air compare optical clocks over the had to operate with extreme accu- link between two of the clocks, air, even in conditions of atmo- racy, and because the wireless link the NIST ytterbium and JILA stron- spheric turbulence and laboratory

9 Spring/Summer 2021 ◊ JILA Light & Matter vibrations. The comb-based sig- evaluating optical atomic clocks. A stration and verification of multi- nal transfer technique had been direct measurement of an optical ple frequency ratio measurements demonstrated previously but the clock frequency in the usual units with uncertainties approaching the latest work was the first to compare of hertz is limited by the accuracy best optical clock performance. state-of-the-art atomic clocks. of the current international stan- All three types of clocks in the dard, the cesium microwave clock. new study offer superlative perfor- Since 1967, the second has been Frequency ratios overcome this mance now and promise further defined based on the cesium limitation because they are not ex- improvements. NIST’s ytterbium atom, which ticks at a microwave pressed in any units. clocks, for example, represent the frequency. The atomic clocks natural frequency of the atoms used in the new comparisons (a value known as systematic tick at much higher optical fre- uncertainty) to within a pos- quencies, which divide time sible error of just 1.4 parts in into smaller units and thus of- 1018—about one billionth of a fer greater precision. Compari- billionth. sons are crucial to the international community’s selection NIST’s new frequency ratio of one or more atoms as the measurements, while re- next time standard. cord-setting, are not quite that good yet. But the research The new NIST results reported team is working on improving in Nature also set other im- measurement stability and portant records. Frequency is clock performance, Hume the most accurately measured said. single quantity in science. The NIST team measured fre- Beyond their role in the next quency ratios, the quantita- generation of internation- tive relationships between the al standards, optical atomic Artist's conceptual illustration of frequencies of the atoms as the linked Atomic Clocks. clocks can be used as sensi- measured in three pairs (ytter- Image Credit: The Ye Group, Steven tive probes for new physics, bium-strontium, ytterbium-alu- Burrows, JILA such as the dark matter be- minum, and aluminum-stron- lieved to constitute most of tium). The results are the three Frequency ratios are usually mea- the "stuff" in the universe. Tech- most accurate measurements sured over long distances by use of nological applications for optical ever made of natural constants. fiber networks, which are few and clocks include improved timing and Frequency ratios are considered far between, or in some cases with navigation systems and measuring constants and are used in some microwave data transferred over Earth’s gravitational shape (geode- international standards and tests satellite links, which tend to be un- sy). of fundamental physics theories. stable. Boulder Atomic Clock Optical Network (BACON) Collaboration*., Beloy, K., Bodine, Frequency ratios offer an import- Guidelines for redefinition of the M.I. et al. Frequency ratio measurements ant advantage as a metric for second recommend the demon- at 18-digit accuracy using an optical clock network. Nature 591, 564–569 (2021).

9 Spring/Summer 2021 ◊ JILA Light & Matter Spring/Summer 2021 ◊ JILA Light & Matter 10 Scientists Dig Deeper into Subject of First-ever Image of a Black Hole

n international team of scien- Atists, including a University of Colorado Boulder researcher, has taken the most detailed look yet at the supermassive black hole at the center of a galaxy called Messier 87. The results suggest the celestial object is surrounded by strong magnetic fields—key in- gredients that could help generate galaxy-length jets of particles that shoot out around it.

The research, published in two studies 24 March 2021 in The As- A new image of M87*, the supermassive black hole at the center of trophysical Journal Letters, is the a galaxy called Messier 87, shows this mysterious object in more latest to emerge from the Event detail than ever before. Horizon Telescope, a collaboration Image Credit: EHT Collaboration that includes more than 300 scientists from five continents draw- ing on observations from several and coordinating author of one of The team’s latest images look at telescopes around the world. the new papers. He said that the the same black hole, but in polar- 2019 image finally gave a face to ized light. That’s a term research- In April 2019, the team made in- black holes. But for scientists like ers use to describe the orientation ternational headlines when it re- him who want to understand how of light waves as they travel through leased the first-ever image of the the bodies behave, it was just the space. (Polarized sunglasses work immediate vicinity of a black hole. beginning. by blocking light with certain orien- That now-famous portrait of this tations, while allowing other light object shows a dark shadow the “I think these new papers are going through). Such data, Dexter said, size of our entire solar system to be a major step forward in using may help scientists to dive deep ringed by a swirling mass of ul- Event Horizon Telescope data to into the belly of a black hole. tra-hot, magnetized plasma called look at how black holes grow,” said an “accretion disk.” Dexter, a JILA fellow and assistant “We’re seeing strong magnetic professor in the Department of As- fields near the black hole,” he said. CU Boulder astrophysicist Jason trophysical and Planetary Scienc- “These fields may be able to ex- Dexter is a member of the Event es. tract energy from the black hole it- Horizon Telescope collaboration self and use it to power these jets.”

11 Spring/Summer 2021 ◊ JILA Light & Matter Rings of fire with the gas. The other idea is that hole itself may twist up the mag- they can become really strong near netic fields in an accretion disk, That hot and volatile environment the black hole and actually push generating built up energy that can is Dexter’s specialty. back against that motion.” occasionally burst out to form jets.

He explained that the tricky thing To probe the nature of those fields, “The Event Horizon Telescope about studying objects like M87*, the Event Horizon Telescope group gives us the ability to study these the black hole at the center of M87 combined data collected from processes where they’re really im- more than 50 million light-years telescopes spread across our own portant—where energy is being from Earth, is that they’re impossi- planet. That information allowed released and where jets are being ble to see on their own. The grav- the team to measure the polariza- launched,” Dexter said. ity produced by black holes is so tion of light from M87’s accretion strong that even light can’t escape disk, which, in turn, holds clues to For now, he’s excited that the data their grasp if it gets too close. the churning dynamics below. coming from the study has, at least so far, matched the theory. Put dif- But scientists can view the area The group’s results suggest that ferently, the images of M87 to date just outside of a black hole and, the black hole’s magnetic fields are look a lot like what researchers ex- in particular, its accretion disk. As anything but weak. pected them to—something Dexter Dexter put it, “We can’t see inside finds comforting. a black hole, but we can study “They’re not being dragged around what’s all around it.” passively with the gas,” Dexter “To me, that’s evidence that we’re said. “They’re strong, and that can on the right track,” he said. “We There’s a lot to study: Accretion change the entire structure of how seem to understand the basic disks form when massive central gas is falling into the black hole, physics of accretion disks and how objects gobble down humungous and even how this black hole is these black holes grow, which to clouds of gas from the surround- growing over time.” me is amazing.” ing space. Like water circling a bathtub drain, that material will be- Bright jets Written by Daniel Strain gin to spin around the black hole the nearer it gets. Scientists have Just what that means for the black The Event Horizon Telescope Collaboration et al. M87 Event Horizon Telescope Results. long suspected that this churning hole isn’t clear yet. VII. Polarization of the Ring, Astrophysical matter could, under the right cir- Journal Letters, 910, L12 (2021). cumstances, generate magnetic Dexter, however, believes that fields—similar to what makes the strong magnetic fields could be the field that causes compasses point key to understanding M87’s explo- north on Earth. sive nature. Scientists have previously observed a humungous “jet” “We have two broad theories for of gas that seems to blast off from what those magnetic fields can look around the black hole and stretch like,” Dexter said. “Some research for potentially tens-to-hundreds of has suggested that they could be thousands of light-years. According weak and are simply dragged along to theory, the rotation of a black

11 Spring/Summer 2021 ◊ JILA Light & Matter Spring/Summer 2021 ◊ JILA Light & Matter 12 Molecules in Flat Lands: An Entanglement Paradise

Within the realm of quantum me- that can be a useful resource for The Importance of Pancake chanics, the generation of quan- quantum sensing and fundamental Geometry tum entanglement remains one of physics tests. Another benefit of the most challenging goals. Entan- using molecules in quantum exper- Chemical reactions are one of the glement, simply put, is when the iments is that molecules also have most detrimental enemies to cool- quantum state of each particle or long-range dipolar interactions: in ing molecules. A few years ago, the a group of particles is not indepen- contrast to atoms which have to Ye lab was able to avoid chemical dent of the quantum states of oth- bump into each other to interact, reactions while allowing molecules er particles or groups, even over molecules can interact at a dis- to interact with each other via di- long distances. Entangled particles tance. “Molecules offer really great polar interactions by loading the have always fascinated physicists, advantages compared to atoms, molecules in a 3D lattice. A 3D as measuring one entangled parti- but at the same time, they are real- lattice can be imagined as a per- cle can result in a change in an- ly hard to cool down. In fact, cooling fect crystal of light. In a 3D lattice, other entangled particle, famously molecules to quantum degeneracy molecules are pinned at individual dismissed as “spooky action at (condition reached when they are lattice sites without moving. The a distance” by Einstein. By now, cold enough to make quantum ef- molecules then interact via dipolar physicists understand this strange fects dominate) has been one of interactions in the same way that effect and how to make use of it, the most sought-after outstanding magnets interact: when they are for example, to increase the sensi- goals for many years. The progress placed side by side they repel and tivity of measurements. However, has been very slow, but it’s hap- when they are placed head to tail entangled states are very fragile, pening now," said Rey. they attract. In a 3D lattice, mol- as they can be easily disrupted by ecules experience both attractive decoherence. Researchers have In 2019, JILA Fellow and Adjoint and repulsive interactions, and, already created entangled states professor for University of Colora- as a consequence, on average the in atoms, photons, electrons, and do Boulder, Jun Ye, finally achieved interactions between molecules ions, but only recently have studies this important milestone. Ye’s lab cancel each other out. Moreover, begun to explore entanglement in managed to cool down molecules in this experiment the molecular gases of polar molecules. consisting of one rubidium and one filling fraction was very low, which potassium atom down to quantum is to say that the molecules were “Molecules are very appealing for degeneracy and observe their mostly quite far apart and interact- quantum simulation, quantum quantum nature. More recently, he ed only very weakly information, and precision mea- has been compressing this molec- surements,” explained Dr. Ana Ma- ular gas into a stack of pancake In a recent experiment, however, ria Rey, a University of Colorado shaped arrays. The work by the the Ye group was able to increase Boulder Adjoint Professor of Phys- Rey and Ye groups investigates the the density by compressing a 3D ics and JILA Fellow. The reason is exciting new physics that emerges quantum degenerate gas into a that molecules have a large num- due to dipolar interactions in such few pancakes, each one with a ber of internal degrees of freedom pancake shaped arrays. flat 2D shape. Within a pancake

13 Spring/Summer 2021 ◊ JILA Light & Matter the Ye group found it is possible work, the interactions between the tanglement we generate becomes to suppress undesirable chemical molecules depend on the quantum robust to certain effects that would reactions and, in addition, make states they are in, and thus on this usually destroy it.” Such entangled dipole interactions stronger. This confinement. So, you first have to arrays of molecules could have ap- is because in a 2D configuration figure out the interactions in this plications for future measurements all molecules repel and the inter- new geometry. It turns out these of various quantities, such as elec- actions do not average out. The actually have very beneficial prop- tric fields, with sensitivity enhanced exciting observation made by the erties for generating the collective by the entanglement.

Model of the quantum gas pancake with quantum interactions Image Credit: The Rey Lab, Steven Burrows, JILA investigators is that the strong di- dynamics we are after.” But the The work done by the Rey group polar interactions in the pancake even better news is that interac- illustrates the importance of geo- can also make the gas robust to tions not only protect the state by metrical effects in dipolar gases undesirable dephasing effects forcing the molecular dipoles to be and the exciting many-body phe- and chemical reactions. As Rey all aligned, but also naturally cre- nomena yet to be explored once Group postdoc Bilitewski stated: ate entanglement. In Bilitewski’s molecules are brought to quantum In studying this shape, “conceptu- words, “The benefit to this collec- degeneracy. In theorizing about ally, and this is at the heart of this tive synchronization is that the en- the importance of this 2D shape,

Spring/Summer 2021 ◊ JILA Light & Matter 14 Rey said: “Thanks to the amazing Highlighting the Research work done by Thomas Bilitewski, we have been able to model their Centers within JILA quantum dynamics and show it should be possible to entangle them. He computed all the inte- grals needed to write an effec- tive model, solved the equations of motion and showed everything can be made to work out to generate entanglement through flip- flop processes induced by dipolar interactions.”

The production of ultracold molecular gases in controllable geom- etries hints at new discoveries and predictions within the field of quantum mechanics. “This observation was a demonstration that molecules can explore quantum magnetism,” Rey added, “In other words, the molecules can behave as quantum magnets and emulate the behavior of electrons in solids, for example. In our recent work, we have made a step forward toward ILA is the host of multiple cen- Technology centers. According to this direction.” The proposal put Jters within its campus. Some Ellen Keister, the STROBE Director forth by the Rey and Ye groups is are National Science Foundation of Education: “STROBE research only the beginning of all the great (NSF) funded and others funded groups have common challenges science yet to be studied with en- by more private centers. Each cen- associated with big data, detec- tanglement arrays of molecules. ter focuses on specific topics to ad- tors, as well as pushing the limits According to Bilitewski, “This is all vance the knowledge, education, of x-ray, electron, and visible na- really exciting in the sense that we and research on some of the big- no-imaging. STROBE enables re- are exploring a novel regime that gest ideas within physics. search groups to address common has only now become available in challenges, enhance tabletop and the lab.” STROBE national facilities, and use new ca- pabilities to address current nano Thomas Bilitewski, Luigi De Marco, Jun-Ru STROBE NSF Science and Tech- and bio materials challenges.” Li, Kyle Matsuda, William G. Tobias, Giacomo Valtolina, Jun Ye, and Ana Maria Rey. nology Center on Real-Time Func- Dynamical Generation of Spin Squeezing tional Imaging is one of the 12 na- While STROBE works on collabora- in Ultracold Dipolar Molecules. Physical Review Letters 126, 113401 (2021). tionwide NSF funded Science and tion between investigators within

15 Spring/Summer 2021 ◊ JILA Light & Matter its center, it also encourages col- Quantum and nanoSystems (PEA- ciplinary universities. The MURIs laboration from a younger genera- QS) works heavily to provide STEM are getting individual professors tion. “STROBE encompasses K–12 opportunities for underrepresent- to work on a collective idea.” This outreach, undergraduate educa- ed undergraduate students. As year is the last year for the current tion, graduate education program- Sarah Schreiner, the PEAQS Co-PI MURI, and it will be renewed soon. ming, essentially focusing on how and STROBE Director of Outreach to build and maintain a top STEM and Broadening Participation ex- The Physics Frontier Center workforce,” Keister comments, plains, “PEAQS is an NSF Partner- (PFC): “and do it in a way that is inclusive, ships for Research and Education and that provides students and in Materials Research (PREM) pro- “I’ve been the admin in the PFC for trainees with the technical and gram. The lead institution is Fort 20 years, before it was the Physics soft skills and tools they need to Lewis College, a non-tribal, Native Frontier Center (PFC). Back then, be prepared and successful when American-Serving Institution, down it was called the Group Grant until they go out into the 21st century in Durango. PEAQS is also partners we won NSF funding to create the workforce.” with Norfolk State University, which PFC center. The PFC then replaced is a member of the Historically the Group Grant.” Krista Beck, an Lauren Mason, STROBE Director of Black Colleges and Universities, administrator, describes her early Communications and Operations, and STROBE. The research pro- work at the PFC. The PFC is one of echoes this importance of collab- vides students with access to the the three NSF centers located on oration, but specifically with the whole cycle of material science, JILA’s campus and hosts around undergraduate population: “Under- all the way from the synthesis and 22 JILA investigators. PI Jun Ye graduate students from across the fabrication of the materials to the explains that the center “is broad- nation who apply to the STROBE characterization and integration of er subject-wise as it touches on Summer Undergraduate Research materials.” PEAQS is an excellent chemistry, biology, and other top- Scholars (SURS) Program have program for undergraduates want- ics.” The PFC encourages active the opportunity to participate in ing to learn the research process, collaboration between investiga- research experiences at multiple as well as find resources for intern- tors to solve some of the biggest STROBE nodes over consecutive ships and future job positions. mysteries within science. summers. Our program is unique in that STROBE offers multiple MID-IR MURI: In fact, this teamwork within the summer research experiences in PFC is quite contagious. “The PFC different labs to develop commu- One center within JILA that is fund- has this nice spirit of collaboration nity and deep technical expertise.” ed by the Department of Defense and I, myself, have collaborated STROBE not only shows the value (DOD) is a multidisciplinary uni- with quite a few PFC investigators of collaboration, but also the value versity research initiative (MURI). in JILA over the past two decades, of educating a younger generation This center is awarded funding to writing many papers together.” Ye of researchers. work on laser technology at JILA states. “And this JILA culture has and other universities. Accord- been extremely powerful. When PEAQS: ing to Eric Cornell: “MURIs have a we were building up Q-SEnSE, the smaller number of people, usually. PFC culture was one we borrowed Like STROBE, The Partnership for They’re very collaborative, right in from, emphasizing on collabora- Education and the Advancement of the name ‘MU’ stands for multidis- tion within Q-SEnSE.” In echoing

15 Spring/Summer 2021 ◊ JILA Light & Matter Spring/Summer 2021 ◊ JILA Light & Matter 16 the power of teamwork, PFC direc- “It connects with other academic physics. As Ye states: “As a scien- tor Eric Cornell adds, “Some of our institutions such as Stanford, MIT, tist, you are always curious wheth- projects are explicitly multi-investi- Harvard, University of New Mexico, er you can advance the knowledge gator projects.” With these multi-in- and national laboratories. They are or technology to the next level.” vestigator projects, PIs use their all connected and collaborating skills to complement each other’s together to solve challenging prob- knowledge in order to successful- lems in quantum information sci- CUbit: ly answer research questions. “It’s ence and technology.” been pretty amazing,” Beck com- The CUbit center is also part of ments. “There have been lots of Q-SEnSE’s collaboration and team- the quantum initiative, and is the papers put out that have more than work extends beyond its own mem- parent organization for Q-SEnSE. one PFC PI, which is really cool. bers, as the center also shares Its goal is to advance fundamental Some theorists and experimen- some common research interests science and build a strong founda- talists will work together across with the Quantum Systems Ac- tion for novel quantum technolo- projects. Acknowledgements will celerator (QSA), a DOE research gies and their rapid dissemination, include also several centers. They center with a goal of building a application, and commercializa- all work together really well.” scalable quantum computer in five tion. Using collaboration within its years. The QSA is led by the Law- sub-centers, CUbit has been able Quantum Systems through rence Berkley National Laboratory, to publish some ground-breaking Entangled Science and En- and partners with CU Boulder and work. gineering (Q-SEnSE): 14 other institutions. Upon thinking of the benefits of having so many CTQM: The research centers within JILA collaborative centers at CU, ONeil also include Quantum Systems comments, “in addition to signifi- The Center for Theory of Quan- through Entangled Science and En- cant research synergies, there is a tum Matter (CTQM) is a sub-cen- gineering (Q-SEnSE). According to reputational advantage that plays ter of CUbit, and is focused solely Director of Operations, Steve ONeil: out in attracting talent. Whether on theory. Director Ana Maria Rey “The Q-SEnSE focus on Quantum it’s at the level of recruiting a junior states that: “we have this synergy Sensors commands a unique sta- professor, the level of a postdoc between research in condensed tus in relation to the related fields looking for a place to work, or the matter, high energy physics, and of quantum simulation, quantum level of a graduate student looking quantum information. This center computing, and quantum network- for a place to study with a profes- allows funding for external speaking, because Quantum Sensing sor to do a Ph.D.” ers and sharing information and and Measurement both underlies new ideas.” Allowing a place for the ultimate success of those other While Q-SEnSE engages prominent theorists specifically to discuss fields and uses them to achieve its researchers from around the world, their work gives way to new types own full technological potential.” it also emphasizes a community of of collaboration. “This is a unique With that in mind, Q-SEnSE derives collaboration and teamwork with- way to be in touch with a different enormous benefits from collabora- in the center and with its many type of community and know what tions among 37 investigators at 11 partners. Q-SEnSE illustrates the they’re doing.” Rey adds. “That’s organizations in the U,S, and one importance of working together to the heart of the center.” in Europe. Director Jun Ye states: advance the boundaries of modern

17 Spring/Summer 2021 ◊ JILA Light & Matter David Jacobson is Awarded the 2021 NIH Pathway to Independence Award

ost-doc David Jacobson in JILA cian-scientists who currently work want to take the techniques I’ve PFellow Tom Perkins’ laboratory in mentored research positions in learned from working with Tom at was ecstatic to discover he had transitioning to independent inves- JILA, and start to apply them to won the competitive NIH K99/R00 tigator positions in academia. “In other biological systems that are Pathway to Independence Award. the short term,” Jacobson added, more directly biomedically relevant “The process of applying for this “it allows me to continue to work than what we’re working with now. award is very involved,” Jacobson on what I’ve been doing with Tom And this award, getting $250,000 said. “I had been in Tom Perkins’ Perkins, which is single molecule a year in research support, is group for three years enough, for example, to when I applied. And you hire two people. Your lab write this big propos- can start bigger sooner, al describing the two and hopefully you get phases, one you do as better results faster.” a postdoc and one you Through this program, do as an independent Jacobson will get the investigator. So, you pre- financial support he pare this big document needs, along with a net- and send it in. It feels work of fellow cohorts, like you’ve done a lot of to transition successful- work. Then you wait a ly into the next phase of long time. And so, when his career. I finally got it, I was kind of relieved that this pro- Jacobson’s goal is to be- cess was over and, of come a professor. As a course, very excited.” postdoc, he is currently Postdoc David Jacobson researching the biophys- Image Credit: The Perkins Lab When asked about this ics of membrane protein type of award, Jacobson folding, as well as im- explained that: “this is a career biophysics experiments on mem- provements on AFM-based force transition award, so there are sci- brane proteins. When I get to the spectroscopy techniques within entific goals, but one of the main point where I am a professor some- the Perkins Laboratory. In transi- goals is my career. So, it’s very where, hopefully, it’ll give me a lot tioning forward, Jacobson hopes humbling to think that the Nation- more initial support to start build- to continue researching protein al Institute of Health (NIH) has ing a lab and really dive into re- folding physics. “I plan to work on set aside a fairly large amount of search.” the arginine vasopressin receptor money to promote my career.” This 2 protein system. I chose that be- grant program from the NIH strives In anticipating his next career cause it has interesting biomedical to support postdoc and clini- moves, Jacobson commented: “I implications, in particular for the

17 Spring/Summer 2021 ◊ JILA Light & Matter Spring/Summer 2021 ◊ JILA Light & Matter 18 urinary condition diabetes insipi- Life after JILA dus, which can be caused by mutations in this protein. There is great interest, from a biomedical point his is our first article in the “Life of view, in doing detailed physical TAfter JILA” series, where we studies of the energetics of how highlight the journeys of JILA alum- this protein assembles and folds. ni, and illustrate the impact that And it is also a protein I think I will JILA has had on their careers. This be able to work with....” article’s focus is on Jason Ensher, EVP and CTO at Insight Photonic Looking back on his work to achieve Solutions. Like many of us, Ensh- this prestigious award, Jacobson er’s career path has been affected thanks his mentor, Tom Perkins. by the environment of industry, the economy as a whole, and new op- “The thing that has always portunities within different fields impressed me with Tom is of physics. In getting to the posi- JILA alumnus Jason Ensher that over his time as a pro- tion that he is in today, Ensher is Image Credit: Jason Ensher fessor in JILA, obviously grateful for the skills he learned, he’s worked on many proj- and experiences he had, at JILA. after talking with him, and ects, but there’s always in According to Ensher, “The people more motivated to get smart- the background this overar- you work with at JILA—they’re your er and become more skilled.” ching project of advancing first professional network.” the underlying measure- The value of a good supervisor was ment technology that we’re Ensher started at JILA the summer not wasted on Ensher’s learning. using.” before his graduate studies began. “I had a really good first impression After graduating from JILA, Ensher Jacobson hopes to mimic Perkins’ of JILA, because I interviewed with moved onto studying at the Uni- goals of advancing technology in Eric Cornell and Carl Wieman on versity of Connecticut. His work his own future work. He is grate- my visit to the university.” Ensher there taught him quite a bit about ful to be receiving this award, and joined Cornell’s team and contrib- the difference in career paths be- can’t wait to get started in reaching uted to the discovery of Bose-Ein- tween academia and industry. his career goals. stein condensate (BEC) of 87RB. “Statistically speaking, unless the Ensher learned many skills under numbers have changed, I think both Cornell and Wieman, skills there are a lot more of us studying which he still uses today. physics than there are positions as full-time faculty.” In observing this, Speaking of his old supervi- Jason felt motivated to pursue a sor, Ensher remarked that career in industry. Cornell “was very support- ive and encouraging in both He began with a small start-up intangible and structured company, Precision Photonics, ways. I always felt smarter then moved to working at Ball Aero-

19 Spring/Summer 2021 ◊ JILA Light & Matter space. From Ball Aerospace, he many applications for these tun- Heather Lewandowski moved through other smaller com- able lasers, including imaging Op- Wins the 2021 Boulder panies until he came to his current tical Coherence Tomography (OCT) Faculty Excellence position at Insight Photonic Solu- for patients with eye ailments, Award tions. Many of his moves between but also applying this product into companies was due to downsizing self-driving cars’ radar technology. and the 2008 recession. He is excited by the challenges his JILA Fellow Heather Lewandowski current job presents, and knows has been awarded the 2021 Boul- In looking back, Ensher observed, his work is making an impact in in- der Faculty Excellence Award. This “I learned one of the most import- dustry as a whole. award was given specifically for Le- ant lessons about working in in- wandowski's excellence in teach- dustry and that is: through no fault In sharing life lessons and wanting ing and pedagogy. of your own, you could be laid off.” to inspire current JILAns, Ensher says: “I would encourage people The Boulder Faculty Excellence This lesson Ensher carried with coming out of graduate school and Awards strive to recognize advanc- him when pursuing other positions. JILA, in particular, to keep in mind es within the university. Candi- He believed it to be an important that you are armed with an incredi- dates are nominated based on in- lesson for anyone working in indus- ble experience and set of skills that novative practices and classroom try. “It’s people in our background not many people have the benefit teaching. Letters from students I think, that are not accustomed of.” Ensher continues to use the and colleagues testify to a candi- to that idea of failing, or being told skills he learned at JILA, and is ex- date's success and allow the selec- ‘your services are not required tremely grateful for having the op- tion committee to assess a candi- here anymore.’ What I would say portunity to work there. date fairly and accurately. from that is: you can’t control when these bad things are going to hap- If you’re interested in learning Heather Lewandowski's group fo- pen to you, but you can definitely more about Life after JILA, or want cuses on experimental cold molec- control how you respond to them.” to join, contact Chris Natynski at ular physics and physics education Reminiscing, [email protected] research. Lewandowski is not only dedicated in her laboratory, but Ensher was grateful of the skills he also studies how students learn learned at JILA that set him apart experimental physics. With both from other applications when try- research topics having interdisci- ing to find his next job. He noticed plinary approaches, it's no wonder that thanks to his training, he was Lewandowski was selected for this able to find his next position rather award. Congratulations! quickly compared with colleagues or friends.

Ensher’s current work still calls on his training learned at JILA, as he is working on making tunable lasers into products. He’s focusing on

19 Spring/Summer 2021 ◊ JILA Light & Matter Spring/Summer 2021 ◊ JILA Light & Matter 20 JILA is a joint institute of the University of Colorado Boulder and the National Institute of Standards and Technology

About JILA JILA was founded in 1962 as a joint institute of CU-Boulder and NIST. JILA is located at the base of the Rocky Moun- tains on the CU-Boulder campus in the Duane Physics complex. JILA’s faculty includes two Nobel laureates, Eric Cornell and John Hall, as well as two John D. and Catherine T. MacArthur Fellows, Margaret Murnane and Ana Maria Rey. JILA’s CU members hold faculty appointments in the De- partments of Physics; Astrophysical & Planetary Science; Chemistry; Biochemistry; and Molecular, Cellular, and De- velopmental Biology, as well as in the School of Engineer- ing. The wide-ranging interests of our scientists have made JILA one of the nation’s leading research institutes in the physical sciences. They explore some of today’s most challenging and fundamental scientific questions about quantum physics, the design of precision optical and x-ray lasers, the fundamental principles underlying the interac- tion of light and matter, and processes that have governed the evolution of the Universe for nearly 14 billion years. Re- search topics range from the small, frigid world governed by the laws of quantum mechanics through the physics of biological and chemical systems to the processes that shape the stars and galaxies. JILA science encompasses eight broad categories: Astro- physics, Atomic & Molecular Physics, Biophysics, Chemical Physics, Laser Physics, Nano- science, Precision Measure- ment, and Quantum Informa- tion Science & Technology. To learn more visit: jila.colorado.edu