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BRIEFINGS TM 2012 RY A RU Space & Physics B FE www.ScientificAmerican.com Inside Complex Organic Molecules in Nebulae 2 Mercury’s Plasma Belt 3 Reaching the Quantum Noise Limit 4 Mirrors That Reflect Matter 5 Neutrino- Antineutrino Violation 5 Optical Black Holes 6 TM BRIEFINGS | Space & Physics 2 versity of Antwerp and col- ASTROCHEMISTRY leagues from Austria, the Neth- BRIEFINGS erlands and Canada have now A gift from the demonstrated an electron vortex stars beam with a diameter of less Scientific American Briefings: Space & Physics than 1.2 Å. consists of summaries of recent peer-reviewed articles from the scientific literature. It draws OBSERVATORIES AROUND the Electron vortex beams were these summaries from the journals of Nature world have recorded infrared first created by passing a plane Publishing Group, including Nature, Nature Nanotechnology, Nature Photonics, Nature emission spectra at wavelengths wave beam through a graphite Physics and the Nature Reviews journals. of 3–20 micrometers from stars film that spontaneously formed tockphoto S Mariette DiChristina and nebulae. These spectra were I a spiral structure, and acted as a Senior Vice President and Editor-in-Chief, initially considered characteris- g/ phase plate. This was difficult to Scientific American eatin tics of polycyclic aromatic hydro- K reproduce and gave limited con- Philip Yam carbons — fused-ring molecules trol over the resulting beam. Ver- Managing Editor, Online, Scientific American ourtney commonly found in burnt food, C beeck and co-workers had im- John Rennie Contributing Editor, Scientific American tar, coal and oil. Tightly focused laser beams, proved on this approach by cre- Michael Mrak Sun Kwok and Yong Zhang at known as optical tweezers, have ating a vortex beam with a Design Director, Scientific American the University of Hong Kong been used to manipulate micro- holographic mask inside a trans- Philip Campbell have now proposed an alterna- scopic objects for two decades. mission electron microscope. Editor-in-Chief, Nature tive hypothesis — that these Andrey Lutich, Jochen Feld- However, the effective beam di- Steven Inchcoombe emission spectra are character- mann and their co-workers at ameter was several micrometers. Managing Director, Nature Publishing Group, and President, Scientific American istic of complex organic mole- the Ludwig–Maximilians Univer- Verbeek and colleagues have Mike Florek cules with disorganized struc- sity in Munich used a similar ap- now reduced this beam diameter Executive Vice President, Scientific American tures. They examined the emis- proach: they suspended a to atomic dimensions by placing a Bruce Brandfon sion spectra from several 60-nanometre gold nanoparticle holographic mask in the con- Vice President and Publisher, Scientific American nebulae and pro-planetary neb- in water in the focal spot of a denser plane of a state-of-the-art Wendy Elman ulae, including the Orion Bar laser beam. They sent sound microscope with double aberra- Vice President, Digital Solutions, Scientific American nebula, and found that the most waves through the water and tion correction. At 1.2 Å, the beam Michael Voss Vice President and Associate Publisher, Marketing fitting model would be if the or- measured changes in the parti- size is comparable to the size of and Business Development, Scientific American ganic molecules contained a cle’s constrained motion. The au- the 2p orbital in a nitrogen atom Christian Dorbandt mixture of aliphatic branches thors calculate that the nanopar- (see image; left and right panels Managing Director, Consumer Marketing, and aromatic rings, and not just ticle can pick up sounds as low show the beam and the 2p orbital Scientific American aromatic rings alone. as −60 decibels, making the set- respectively, drawn approximately Matt Hansen Senior Production Editor, Nature Publishing Group In fact, recent laboratory anal- up a million times more sensi- to scale). The tiny vortex beam Kerrissa Lynch yses have identified organic mole- tive than the human ear. may allow atomic-resolution Web Production Editor, Scientific American cules with a chemical structure —Eugenie Samuel Reich, mapping of magnetic states. HOW TO CONTACT US similar to that described above in Nature —Michael Segal, For subscription correspondence, including the Murchison meteorite. The re- Nature Nanotechnology change of e-mail addresses: ■■ Phys. Rev. Lett. doi: 10.1103/ U.S. and Canada: 800-333-1199 searchers suggest that organic Outside the North America: +1-515-248-7684 molecules might exist throughout PhysRevLett.108.018101 (2012) ■■ Appl. Phys. Lett. doi: 10.1063/1.3662012 Email: [email protected] (2011) Postal address: Scientific American Briefings, Box the universe, and that meteorites 3187, Harlan, IA 51537 might have carried these mole- Annual subscription (12 issues): $19.95 (USD) ELECTRON BEAMS For editorial comments: cules from distant galaxies to our TECHNIQUES Email: [email protected] solar system. An atom-sized www.ScientificAmerican.com —Edward Duca, Cooling by Nature China vortex Scientific American is a trademark of ELECTRON BEAMS are typically numbers Scientific American, Inc., used with permission. ■■ Nature doi: 10.1038/nature10542 (2011) plane waves. This means that the LIKE ELECTRONS trapped in the beam phase is identical for all potential of a nucleus, bosonic PHYSICS points in a plane perpendicular atoms residing at the individual TM to the beam direction. The phase sites of an optical lattice — a peri- ‘Nanoear’ hears of an electron vortex beam, on odic structure defined by inter- the other hand, describes a fering laser beams — can occupy small sounds spiral. As a result, vortex beams discrete motional orbitals. BY USING laser beams to trap a carry orbital angular moment Waseem Bakr and colleagues gold nanoparticle, researchers in and magnetic moment, which have now implemented a tech- Germany have developed a sensi- leads to unique interactions with nique for deterministically con- tive sound-wave detector. matter. Jo Verbeeck of the Uni- trolling the distribution of atoms SUBSCRIBE >> TM BRIEFINGS | Space & Physics 3 across these different energy water in a rotating magnetic trons at a distance of about half states, and establish it as a new field, which triggered nickel the planet’s radius from the means of cooling quantum gases. nanowires in the tank to rotate surface. The key is a mechanism in turn, generating microvor- The authors compare the belt Bakr et al. call “orbital excitation tices. The vortices trapped poly- to Earth’s ring current and say blockade.” They transfer ground- styrene microbeads in the water. that it could influence the pat- state atoms to a higher orbital by By controlling the movement of tern of surface weathering and modulating the lattice depth at a the nanowires, the authors could the formation of a thin atmo- suitable frequency; but once one tightly control the movement of sphere around Mercury. atom is transferred, it shifts the the beads. —Emma Maris, Nature ON THE COVER energy levels to a degree that They also successfully manip- ■■ Geophys. Res. Lett. doi: Light from the Orion Nebula, other atoms at the same site are ulated Escherichia coli bacteria 10.1029/2011GL049629 (2011) one of the most arresting pushed off-resonance — the first using a pair of microspheres in sights in the night sky, excitation blocks further ones. place of the nanowires. suggests that some highly Bakr and colleagues use this —Daniel Cressey, Nature interesting mixture of mechanism to reshuffle and se- ■■ Nano Lett. 10.1021/nl2032487 (2011) WAVEgUIDES complex organic molecules lectively remove atoms from a can be found near these lattice with random occupation Luminous stellar remnants. See page 2. numbers. As atom-number fluc- PLANETARY SCIENCE tuations across the lattice are the repulsion Credit: ESO/J. Emerson/ main source of entropy, levelling Mercury’s enhanced VISTA/Cambridge the number of atoms at each site Astronomical Survey Unit amounts to cooling the gas. The plasma belt WHEN A dielectric particle is ex- authors expect that in the future posed to a strong optical gra- their method can also serve in dient it becomes electrically po- ton quantum computations on op- g larized and subject to an attrac- hysics P tical-lattice systems. ASHIN tive force in the direction of f W f O —Andreas Trabesinger, PPLIED increasing field strength. This is A Nature Physics the principle by which optical nstitution niversity tweezers are able to trap and ma- I U ■■ IE Nature doi: 10.1038/nature10668 (2011) g nipulate living cells and other ARNE OPKINS /C H microscopic objects. NANOTECHNOLOgY OHNS A similar force can be gener- aboratory ated between two light-carrying NASA/J L Swirls move Mercury. microscopic (and nanoscopic) waveguide structures. Moreover, tiny objects LIKE EARTH, Mercury has a the sign of the force can be INDIVIDUAL CELLS can be ma- magnetosphere, a zone of inter- tuned from attractive to repul- nipulated by tiny vortices gener- action between its magnetic field sive by shifting the phase of the ated in fluids, rather than by the and incoming plasma from the light travelling in one waveguide potentially harmful lasers or Sun. But scientists have been un- relative to the other — which is electric fields typically used. The sure about whether Mercury also potentially useful for optome- concept is the brainchild of Li has the concentration of charged chanical sensing and switching Zhang and his colleagues at the particles around its equator that applications. Unfortunately, the Swiss Federal Institute of Tech- Earth does. magnitude of such forces is nology in Zurich, who used the David Schriver at the Univer- much less than the force exerted vortices to control the movement sity of California, Los Angeles, by optical tweezers. And at small of microscopic objects. and his colleagues argue that separations the sign is invariably The team placed a tank of Mercury does have such a quasi- attractive. Scientific AmericanBriefings, Space & Physics, Volume 1, Number 2, trapped particle belt, citing sim- Ardavan Oskooi and col- February 2012, published monthly by Scientific American, a division of Nature America, Inc., 75 Varick Street, 9th Floor, New York, NY 10013-1917.