2003/03/31 by Anatoli Polkovnikov · 12 citations
Computer Science · Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Quantum Information and Cryptography #Strong Light-Matter Interactions #cond-mat.stat-mech #quant-ph
paper · pdf · doi:10.1103/physreva.68.053604
published as Phys. Rev. A, vol. 68 (5), 053604 (2003) · published version
openalex publication_date 2003/11/04 · arxiv created 2005/08/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We develop a consistent perturbation theory in quantum fluctuations around the classical evolution of a system of interacting bosons. The zero-order approximation gives the classical Gross-Pitaevskii equations. In the next order we recover the truncated Wigner approximation, where the evolution is still classical but the initial conditions are distributed according to the Wigner transform of the initial density matrix. Further corrections can be characterized as quantum scattering events, which appear in the form of a nonlinear response of the observable to an infinitesimal displacement of the field along its classical evolution. At the end of the paper we give a few numerical examples to test the formalism.