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Quantum quench of an atomic Mott insulator
David Chen1, Matthew White, Cecilia Borries
1Department of Physics, University of Illinois, 1110 West Green Street, Urbana, Illinois 61801, USA.
Physical Review Letters
|July 21, 2011
Summary
Ultracold atoms in optical lattices undergo quantum phase transitions. Quenching across the Mott insulator to superfluid phase reveals excitation dynamics following a power-law dependence on quench rate, analogous to classical phase transitions.
Area of Science:
- Quantum physics
- Ultracold atomic gases
- Condensed matter physics
Background:
- Bose-Hubbard model describes interacting bosons in optical lattices.
- Quantum phase transitions (QPTs) occur at zero temperature.
- Mott insulator and superfluid are distinct quantum phases.
Purpose of the Study:
- Investigate quantum phase transitions in ultracold atomic gases.
- Characterize excitation dynamics during a quench.
- Explore the analogy with the Kibble-Zurek mechanism.
Main Methods:
- Utilizing ultracold atomic gases trapped in optical lattices.
- Performing quenches across the Mott insulator-to-superfluid QPT.
- Measuring condensate excitations via time-of-flight imaging.
Main Results:
- Observed excitation degree proportional to atoms crossing the phase boundary.
- Quantified power-law dependence of excitations and energy on quench rate.
- Demonstrated phenomena analogous to the Kibble-Zurek mechanism.
Conclusions:
- Quenches in ultracold atomic gases exhibit universal scaling laws.
- The Kibble-Zurek mechanism provides a framework for understanding quench dynamics.
- This study offers insights into defect generation during nonequilibrium QPTs.
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