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September 2009 Joint Quantum ψ Institute News for September 2009 A Summer of Outreach: A New JQI Fellow and a Distinguished Visitor Students from Middle School This month JQI welcomes two arrivals international standard for the duration of who bring additional strength and depth the second, rely on the natural frequency to College, to the Institute’s inventory of talent. at which cesium atoms oscillate between High-school two quantum conditions: a ground state Teachers and One is the newest JQI Fellow, Gretchen and an excited state. At present, the sec- REU Days Campbell, who will be a staff physicist at ond is defined as the time it takes a cesi- pages 3-5 the National Institute of Standards and um-133 atom to complete 9,192,631,770 Technology (NIST) starting September cycles between these states. That fre- 15. She received her quency falls into the Hacking the Ph.D from MIT, where microwave range of Quantum she worked in Wolf- the electromagnetic At DEFCON gang Ketterle’s and spectrum. And More: Dave Prichard’s lab and Entangled studied rubidium Bose- The best existing States Einstein condensates in cesium clocks, such optical lattices. as NIST’s F-1, have an page 6 accuracy of a few parts Most recently, Campbell in 10 quadrillion (1016), Upcoming was at JILA, a partner- but that is not suf- Workshop: ship between NIST ficiently exact for the and the University of increasingly precise Ultracold Colorado, where she demands of 21st-cen- was a research associ- tury science and tech- Group II ate in the Jun Ye group. JQI Fellow Gretchen Campbell nology. So researchers Atoms Among other pursuits, are exploring numer- Sept. 17-19 she was engaged in the effort to develop ous alternatives for higher accuracy. University of a strontium optical lattice clock -- and in Maryland the construction of a novel experimental One very promising idea is to use an for details, see apparatus that is used to explore elec- atomic transition that occurs about tronic transitions in strontium atoms. The a hundred thousand times faster -- a jqi.umd.edu/ frequency of such transitions is the fun- frequency in the optical range of EM workshop.html damental basis of modern timekeeping. radiation. Among the optimal candidate atoms is strontium. The world’s master clocks, as well as the continued on page 2 Campbell and Carmichael from p. 1 At JQI, Campbell will continue research, begun in encountered in quantum optics according to a scat- the Ye group, into using an array of strontium atoms tering scenario, in which the inputs are classical fields confined in an optical lattice -- a sort of grid pat- (external fields) and the outputs are classical stochas- tern formed by the intersection of two or more laser tic processes that model the scattered fields after beams -- as a platform for quantum simulations of detection (after their measurement). many-body physics problems and as a potential clock mechanism. “The mapping from inputs to outputs is provided by a quantum stochastic process that is set up to ac- One extremely difficult aspect of this work involves count for a particular measurement strategy (e.g., exploiting a transition, artificially induced by numer- photon counting, homodyne/heterodyne detection, ous lasers acting in concert, that appears to be very etc.). Both the formal theory and its applications are stable. Creating, controlling and measuring that under study. Recent work includes the development transition require exquisitely delicate manipulation of of a novel measurement scheme to correlate the nuclear spin states using lasers and related apparatus. quadrature amplitudes of an electromagnetic field, applications of this scheme in In addition, Campbell will continue cavity quantum electrodynamics, the investigations begun at NIST by and the modelling of multimode departing JQI Fellow Kris Helmer- aspects of collective radiative son into the behavior of Bose-Ein- phenomena (super-radiance). stein condensates in toroid (do- nut-shaped) configurations. That Entanglement and Correlation in arrangement has advantages for Composite Systems certain kinds of study. For example, an ordinary BEC has a substantial “Quantum optics has traditionally density gradient, thinning out from concerned itself with uniquely the center to the edges. A toroidal quantum mechanical aspects of BEC has a much more uniform den- optical phenomena (e.g., photon sity. In addition, it provides a closed antibunching and squeezing, loop in which atoms can move or violations of Bell inequalities). forces can propagate, allowing a Attention in recent years has wide range of effects. been focused on applications of these quantum features of light The Kiwi Connection to novel schemes for processing information (so-called quantum The second arrival this month is information science). Entangled Professor Howard Carmichael of the states are central to the proposed University of Auckland (New Zea- information processing proto- land) Physics Department. Carmi- Visiting Professor Howard Carmichael cols. chael, an expert in cavity quantum electrodynamics and a Fellow of both the American “Current work is directed towards understanding Physical Society and the Optical Society of America, entangled states, and the contextual correlations they holds the Dan Walls Chair in Theoretical Physics. He is describe, in the broadest sense, i.e.,we are concerned spending a sabbatical year at JQI, where he will work with the physics of composite quantum systems in with many Fellows including Luis Orozco, whom Car- general. Specific interests include measures of en- michael met years ago when both were at the Univer- tanglement for open systems, and schemes for the sity of Texas at Austin. generation and manipulation of this entanglement. Continuous variable entanglement is of particular His current research is concentrated in two areas, interest. It has been suggested by others that this which he describes as follows: form of entanglement can be accounted for within stochastic electrodynamics. The suggestion is being Quantum Trajectory Theory assessed. A quantum trajectory theory of continuous variable teleportation is being developed for compar- “Quantum trajectory theory treats the open systems ison with the stochastic electrodynamics proposal.” 2 Summer Outreach 1: H.S. Teachers Physics in Focus: On June 26, 2009, JQI’s Physics Frontier Center conducted a day-long workshop on optics in the classroom for local-area high school physics teachers, using instructional materials from the Optical Society of America. The first half of the event was devoted to demonstrations and discussion of techniques to illustrate optical phenomena. The second half involved a tour of several JQI laboratories to see some of the ways in which quantum optics is employed in ongoing research. Clockwise from left: PFC Co-Director Luis Orozco works with Faiz Mohideen of Largo (MD) High School. PFC Co-Director Bill Phillips with Mohideen and Sarah Wendel of Parkdale High School (Riverdale, MD). Postdoc Steve Olmschenk explains an ex- periment to Wendel and Herb Edelstein of Richard Montgomery High School (Rockville, MD). Above left: Wendel and Sederik Rice, of Bowie (MD) High School experiment with laser demonstrations for classroom use. Above right: JQI Co-Director Steve Rolston takes questions after a presentation on techniques and materials for teaching optics. Other participating teachers were: Christopher Hahn of Linganore High School (Ijamsville, MD); Jasper Layne of Largo (MD) High School; and Yau-Jong Twu, Eleanor Roosevelt High School (Greenbelt, MD). 3 Summer Outreach 2: REU Projects 2009 Summer Research Experience for Inter- national Undergraduates: Three undergradu- ate students spent ten weeks working with JQI researchers this summer. Two were from Mexico -- Jorge Gomez (Uni- versidad de Guadalajara) and Diego Quiñones (Universidad Autónoma de San Luis Potosí). They were selected by the division of Quantum Information of Sociedad Mexicana de Fisica (Mexican Physical Society) after a national com- petition and worked in the group of JQI Fellow Luis Orozco, shown in top and bottom photos. The third student -- Douglas Onyago, originally from Kenya -- is an undergraduate at Williams College in Massachusetts. He contacted JQI after learning of opportunities at the Annual Meeting of the National Society of Black Physi- cists and the National Society of Hispanic Physi- cists in Nashville, TN where JQI and its Physics Frontier Center had a booth. Onyago (at right in center photo) worked in the group of JQI Fel- low Trey Porto (at left in center photo). Gomez (center in bottom photo) worked with JQI graduate student Dong Sheng (left in photo) on a “Magnetic field sensor and feed- back system for precise spectroscopy in an atom trap”. Quiñones (at right in top photo) worked with JQI researcher Jonathan Hood (center of photo) on “Analysis of a Microwave Cavity and Antenna for driving a Parity Violating Transition”. Onyago worked with JQI student Creston Herold (not shown) on “Atomic beam collimators for Rb/Yb experiment.” Their stay was supported by JQI, which thanks the REU MRSEC site at UMD for its hospitality in facilitating the students’ stay and making them part of the group. All photos were taken at the final poster ses- sion for the REU MRSEC in August 2009. Photos courtesy of Julie Callis/MRSEC 4 Summer Outreach 3: H.S. Students Getting the Point: This summer, the Chris Monroe group added two high-school seniors to its lab team: Grace Young and Jennifer Wang. Their job was to test a “parabolic dish” trap in which individual 5-micron hol- low polystyrene spheres are confined and irradiated by laser light. The spheres serve as a point source, scat- tering light in all directions. When a sphere is placed at the focus of the dish, more than half its light emerges vertically and can be collimated and routed to a fiber. Eventually, the group will use the trap configura- tion to hold a single atom, thereby achiev- ing very high collec- tion efficiency of single Above: Students Grace Young (left) of The Potomac photons.
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