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.
To add your name to the Quantum Lunch email list, contact Ellie Vigil

Thursday, November 3, 2011
12:30 PM - 2:00 PM

Speaker: Brian DeMarco (University of Illinois at Urbana-Champaign)

Technical Host: Bogdan Damski

TOPIC: Quantum Quenches in an Optical Lattice

Abstract
The study of non-equilibrium phase transitions is wide ranging, touching on topic as diverse as the formation of structures in the early Universe and the practicality of quantum computing. Recently, interest has turned to the theory of quenches across quantum phase transitions. Quench in this context refers to rapidly varying a parameter in the Hamiltonian in order to tune between ground-state quantum phases. While there has been a great deal of theoretical attention paid to this problem, experimental study has been scant. I will talk about our recent measurements of quantum quenches across the bosonic Mott-insulator superfluid phase transition accomplished using an optical lattice. We trap ultra-cold atoms in a crystal of light an optical lattice created from the intersection of laser beams. By rapidly changing the intensity of the laser light, we quench the atoms between a localized Mott insulator and a superfluid state. We observe that excitations such as vortices are created during this process. We show that the number of excitations is proportional to the fraction of atoms crossing the phase boundary and has a power-law dependence on the quenching rate. I will also briefly mention our recent demonstration of Anderson localization of 3D quantum matter waves.