Physics – Condensed Matter – Statistical Mechanics
Scientific paper
2009-05-19
Phys. Rev. A 80, 033624 (2009)
Physics
Condensed Matter
Statistical Mechanics
20 pages, 6 figures
Scientific paper
10.1103/PhysRevA.80.033624
The applicability of the so-called truncated Wigner approximation (-W) is extended to multitime averages of Heisenberg field operators. This task splits naturally in two. Firstly, what class of multitime averages the -W approximates, and, secondly, how to proceed if the average in question does not belong to this class. To answer the first question we develop an (in principle, exact) path-integral approach in phase-space based on the symmetric (Weyl) ordering of creation and annihilation operators. These techniques calculate a new class of averages which we call time-symmetric. The -W equations emerge as an approximation within this path-integral techniques. We then show that the answer to the second question is associated with response properties of the system. In fact, for two-time averages Kubo's renowned formula relating the linear response function to two-time commutators suffices. The -W is trivially generalised to the response properties of the system allowing one to calculate approximate time-normally ordered two-time correlation functions with surprising ease. The techniques we develop are demonstrated for the Bose-Hubbard model.
Berg Bernd
Fleischhauer Michael
Olsen Murray K.
Plimak L. I.
Polkovnikov Anatoli
No associations
LandOfFree
Commuting Heisenberg operators as the quantum response problem: Time-normal averages in the truncated Wigner representation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Commuting Heisenberg operators as the quantum response problem: Time-normal averages in the truncated Wigner representation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Commuting Heisenberg operators as the quantum response problem: Time-normal averages in the truncated Wigner representation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-700134