The interplay between ultracold atoms, semiconductor surfaces and quantum electronic systems

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• Prof. Mark Fromhold, U of Nottingham
• Thursday 31 March 2011, 13:45-15:00
• Theory Library.

If you have a question about this talk, please contact Dr Dimitri M Gangardt.

This talk will explore how room-temperature semiconductor surfaces can manipulate atoms cooled to nK temperatures and, conversely, be probed by the atoms themselves.

Quantum-mechanical reflection can shield the ultracold atoms from the disruptive influence of a nearby room-temperature surface. By considering experiments performed at MIT [1], it will be shown that inter-atomic interactions and the aspect ratio of the condensate both strongly affect the reflection process [2].

Next, the interaction between atomic condensates and surfaces that are patterned on the nanometre and micrometre scales will be considered. Strong focusing of the condensate by a transmission zone plate suggests a route towards re-writable matter-wave lithography of quantum electronic devices [2].

Finally, I will present calculations, which predict that current through a two-dimensional electron gas (2DEG) can trap ultracold atoms < 1 micron away with orders of magnitude less spatial noise than a more usual metal trapping wire [3]. This may enable the creation of hybrid systems, which integrate ultracold atoms with quantum electronic devices to give high sensitivity and control: for example, activating a single quantised conductance channel in the 2DEG can split a Bose-Einstein condensate (BEC) for atom interferometry. In turn, the BEC itself offers structural and functional imaging of quantum devices and transport.

[1] T.A. Pasquini, Y. Shin, C. Sanner, M. Saba, A. Schirotzek, D.E. Pritchard, and W. Ketterle, Phys. Rev. Lett. 93, 223201 (2004).

[2] R.G. Scott, A.M. Martin, T.M. Fromhold, and F.W. Sheard, Phys. Rev. Lett. 95, 073201 (2005); T.E. Judd, R.G. Scott, G. Sinuco, T.W.A. Montgomery, A.M. Martin, P. Krüger, and T.M. Fromhold, New J. Phys. 12, 063033 (2010).

[3] G. Sinuco-León, B. Kaczmarek, P. Krüger, T.M. Fromhold, Phys. Rev. A 83 , 021401® (2011)

This talk is part of the Theoretical Physics Seminars series.

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