Truncated Wigner approximation as a non-positive Kraus map
arXiv:2108.04189 · doi:10.1088/1402-4896/ab8d53
Abstract
We show that the Truncated Wigner Approximation developed in the flat phase-space is mapped into a Lindblad-type evolution with an indefinite metric in the space of linear operators. As a result, the classically evolved Wigner function corresponds to a non-positive operator , which does not describe a physical state. The rate of appearance of negative eigenvalues of can be efficiently estimated. The short-time dynamics of the Kerr and second harmonic generation Hamiltonains are discussed.