title: von neumann equations with time-dependent hamiltonians and supersymmetric quantum mechanics
abstract: Starting with a time-independent Hamiltonian h and an appropriately chosen solution of the von Neumann equation irho;(t)=[h,rho(t)] we construct its binary-Darboux partner h(1)(t) and an exact scattering solution of irho;(1)(t)=[h(1)(t),rho(1)(t)], where h(1)(t) is time dependent and not isospectral to h. The method is analogous to supersymmetric quantum mechanics but is based on a different version of a Darboux transformation. We illustrate the technique by the example where h corresponds to a one-dimensional harmonic oscillator. The resulting h(1)(t) represents a scattering of a solitonlike pulse on a three-level system.
authors.affiliation: Wydzial Fizyki Technicznej i Matematyki Stosowanej, Politechnika Gdanska, ul. Narutowicza 11/12, 80-952 Gdansk, Poland and Arnold Sommerfeld Institut fur Mathematische Physik, Technische Universitat Clausthal, 38678 Clausthal-Zeller.
authors.initials: M
authors.lastname: Czachor
authors.initials: HD
authors.lastname: Doebner
authors.initials: M
authors.lastname: Syty
authors.initials: K
authors.lastname: Wasylka