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 Charlotte Lehman

Thursday, December 3, 2009
12:30 PM - 2:00 PM

Speaker: Rolando Somma, T-4

Technical Host:

TOPIC: Necessary Conditions for the Quantum Adiabatic Approximation

Abstract
A gapped quantum system that is adiabatically perturbed remains in its eigenstate after the perturbation. We prove that, for constant gap, general quantum processes that approximately prepare the final eigenstate require a minimum time proportional to the ratio of the length of the eigenstate path to the gap. Thus, no rigorous adiabatic condition can yield a smaller cost. We also give a necessary condition for the adiabatic approximation that is suitable for those cases where the gap varies.