Quantum Institute: Visitor Schedule

The Quantum Lunch is regularly held on Thursdays in the Theoretical Division Conference Room, TA-3, Building 123, Room 121.
For more information, contact Diego Dalvit.

November 15, 2007
Thursday, 12:30PM to 2 PM
T-DO Conference Room, TA-3-123-121

Lincoln D. Carr,
Colorado School of Mines

Cat States in Bose-Einstein Condensates

Abstract

It is vital not to take our most fundamental physical theories for granted. For example, researchers have looked for deviations from the gravitational inverse square law at very small sub-micron length scales. Similarly, one can ask what predictions of quantum mechanics might break down in untested regimes. Since the classical world is macroscopic and the quantum world is microscopic, a natural place to test quantum mechanics is in mesoscopic physics. Macroscopic superposition is a largely untested mesoscopic prediction of quantum mechanics.

An excellent candidate for macroscopic superposition states, also called Cat (or NOON) States after Schrodinger's famous gedanken experiment, is a Bose-Einstein condensate in a double well. Mathematically, this is a 50-year-old quantum many body problem. The experimental context of Bose-Einstein condensates gives one hope to observe the first truly large scale Cat States of matter. We show that Bose-Einstein condensates require two new energy scales. We introduce the role of the dimensionality of each well. We demonstrate that the many body wavefunction serves to protect Cat States from decoherence. Finally, we present a practical scheme for dynamic realization of such states.