title: Quasiprobability distributions in stochastic wave-function methods
metadata.name: dc.contributor.author
metadata.value: Polyakov, Evgeny A.
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Vorontsov-Velyaminov, Pavel N.
metadata.lang: -
metadata.name: dc.date.accessioned
metadata.value: 2015-04-20T13:10:31Z
metadata.lang: -
metadata.name: dc.date.available
metadata.value: 2015-04-20T13:10:31Z
metadata.lang: -
metadata.name: dc.date.issued
metadata.value: 2015-04-08
metadata.lang: -
metadata.name: dc.identifier.citation
metadata.value: Phys. Rev. A 91, 042107
metadata.lang: en_GB
metadata.name: dc.identifier.uri
metadata.value: http://hdl.handle.net/11701/1442
metadata.lang: -
metadata.name: dc.description.abstract
metadata.value: Quasiprobability distributions emerging in the stochastic wave-function method of Carusotto et al. [Phys. Rev. A 63, 023606 (2001)] are investigated. We show that there are actually two types of quasiprobabilities. The first one, the “diagonal Hartree-Fock state projection” representation, is useful in representing the initial conditions for stochastic simulation in the most compact form. It defines antinormally ordered expansion of the density operator and normally ordered mapping of the observables to be averaged. We completely characterize the equivalence classes of this phase-space representation. The second quasiprobability distribution, the “nondiagonal Hartree-Fock state projection” representation, extends the first one in order to achieve stochastic representation of the quantum dynamics. We demonstrate how the differential identities of the stochastic ansatz generate the automorphisms of this phase-space representation. These automorphisms turn the stochastic representation into a gauge theory. The gauge transformations of the quasiprobability master equation are described. In particular, it is the analyticity of the stochastic ansatz that allows one to transform the master equation into the genuine Fokker-Planck equation. We demonstrate how the different variants of the stochastic wave-function method can be constructed, first by choosing a certain optimality criteria or constraints, and then by satisfying these criteria with a suitable choice of gauge. The problem of boundary terms is considered. It is demonstrated that the simple scheme with Fock states of Carusotto et al. is not subjected to this problem.
metadata.lang: en_GB
metadata.name: dc.description.sponsorship
metadata.value: Russian Foundation for Basic Reseach Grant No. 14-02-31109, Saint Petersburg State University Grant No. 11.50.1573.2013
metadata.lang: en_GB
metadata.name: dc.language.iso
metadata.value: en
metadata.lang: en_GB
metadata.name: dc.publisher
metadata.value: Americal Physical Society
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: Quantum Mechanics in Phase Space
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: Open Quantum Systems
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: Quantum Noise
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: Stochastic Differential Equations
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: Quantum Simulations
metadata.lang: en_GB
metadata.name: dc.title
metadata.value: Quasiprobability distributions in stochastic wave-function methods
metadata.lang: en_GB
metadata.name: dc.type
metadata.value: Article
metadata.lang: en_GB
resources.filename: PhysRevA.91.pdf
resources.url: https://dspace.spbu.ru/bitstream/11701/1442/1/PhysRevA.91.pdf
resources.format: Adobe PDF
resources.description: Full-text article
resources.size: 287,9 kB