English

Universal density matrix for the phase space

Mathematical Physics 2019-04-11 v1 math.MP Quantum Physics

Abstract

In this paper, a new representation of the Wigner function for a quantum system in the phase space is proposed. The new representation is of the form W=Sp[ρW]W=\operatorname{Sp}\left[ \rho \mathcal{W} \right], where ρ\rho is the density matrix, and W\mathcal{W} is the universal density matrix. The density matrix ρ\rho for each quantum system is different, and the universal matrix W\mathcal{W} is the same for any quantum system. Thus, the matrix W\mathcal{W} has a fundamental character. In the work, the elements of the universal matrix W\mathcal{W} were found explicitly and their properties were investigated. The diagonal elements of the matrix W\mathcal{W} are the Wigner functions of the harmonic oscillator, which do not introduce dissipation into the quantum system. The off-diagonal elements of the matrix W\mathcal{W} contain frequency oscillations responsible for dissipations in the quantum systems.

Keywords

Cite

@article{arxiv.1904.04950,
  title  = {Universal density matrix for the phase space},
  author = {E. E. Perepelkin and B. I. Sadovnikov and N. G. Inozemtseva and E. V. Burlakov},
  journal= {arXiv preprint arXiv:1904.04950},
  year   = {2019}
}

Comments

30 pages, 3 figures

R2 v1 2026-06-23T08:34:52.240Z