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Publication - Dr Roman Schubert

    Lindblad dynamics of Gaussian states and their superpositions in the semiclassical limit

    Citation

    Graefe, EM, Longstaff, B, Plastow, T & Schubert, R, 2018, ‘Lindblad dynamics of Gaussian states and their superpositions in the semiclassical limit’. Journal of Physics A: Mathematical and Theoretical, vol 51.

    Abstract

    The time evolution of the Wigner function for Gaussian states generated by Lindblad quantum dynamics is investigated in the semiclassical limit. A new type of phase-space dynamics is obtained for the centre of a Gaussian Wigner function, where the Lindblad terms generally introduce a non-Hamiltonian flow. In addition to this, the Gaussian approximation yields dynamical equations for the covariances. The approximation becomes exact for linear Lindblad operators and a quadratic Hamiltonian. By viewing the Wigner function as a wave function on a coordinate space of doubled dimension, and the phase-space Lindblad equation as a Schrödinger equation with a non-Hermitian Hamiltonian, a further set of semiclassical equations are derived. These are capable of describing the interference terms in Wigner functions arising in superpositions of Gaussian states, as demonstrated for a cat state in an anharmonic oscillator subject to damping.

    Full details in the University publications repository