Title: Integrated Coherent Matter Wave Circuits
The emerging field of atomtronics seeks to build atomic circuits in which currents are formed by coherent matter waves flowing inside complex waveguide structures. Motivations for developing this technology include creating compact waveguide atom interferometer rotation sensing and realizing new forms of signal processing and analysis. In this talk I will present our recent work demonstrating atomtronic circuits aimed towards such goals. The technology used in all of this work is the Painted Potential , a combination of two red-detuned optical dipole traps for cold atoms. In this sys-tem a rapidly-moving tweezer beam “paints” a desired 2D potential on top of a static horizontal light sheet. Bose-Einstein condensates (BECs) created in the resulting time-averaged trap can then be manipulated by adiabatically changing the potential. One of the first atomtronic circuit devices studied was the BEC analog of the Superconducting Quantum Interference Device (SQUID). In our dc atom-SQUID device , a BEC was created in a toroidal potential with two thin potential barriers. We observed that the barriers behaved as ideal Josephson Junctions. I will discuss this work and our progress towards observing quantum interference in the atom-SQUID. The Painted Potential can also re-alize and integrate the basic elements needed to create complex matter wave circuits . Tilting a waveguide contain-ing a BEC will accelerate it to a desired velocity. We have propagated these moving condensates around bends con-necting straight waveguides, around closed waveguide loops, and through Y-junctions which can act as switches and coherent beamsplitters. I will present these results and discuss the challenges associated with ensuring single-mode propagation in atomtronic circuits.
References: K. Henderson, C. Ryu, C. MacCormick, and M. G. Boshier, New J. Phys. 11, 043030 (2009). C. Ryu, P. W. Blackburn, A. A. Blinova, and M. G. Boshier, Phys. Rev. Lett. 111, 205301 (2013). C. Ryu and M. G. Boshier, New J. Phys. 17, 092002 (2015).
Dr. Malcolm Boshier is a Staff Scientist in the Physics Division at Los Alamos National Laboratory. After undergradu-ate study at the University of Otago in New Zealand, he obtained a D.Phil. degree from Oxford University. Dr. Boshier is an APS Fellow and the director of the Quantum Institute at Los Alamos.
Every Friday 10:45-11:45 a.m., COB 267 (except as noted). Tea and cookies will be served from 10:30 - 10:45 a.m. Questions regarding the seminar series should be directed to Prof. Bin Liu