In: Physical Review A - Atomic, molecular and optical physics, 2012, vol. 85, no. 1, p. 013822
We present a theoretical technique for solving the quantum transport problem of a few photons through a one-dimensional, strongly nonlinear waveguide. We specifically consider the situation where the evolution of the optical field is governed by the quantum nonlinear Schrödinger equation. Although this kind of nonlinearity is quite general, we focus on a realistic implementation involving cold...
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In: Physical Review Letters, 2012, vol. 108, no. 8, p. 080404
We study the influence of geometry of quantum systems underlying space of states on its quantum many-body dynamics. We observe an interplay between dynamical and topological ingredients of quantum nonequilibrium dynamics revealed by the geometrical structure of the quantum space of states. As a primary example we use the anisotropic XY ring in a transverse magnetic field with an additional...
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In: Physical Review B, 2010, vol. 81, no. 1, p. 012303
We study the dynamical response of a system to a sudden change of the tuning parameter λ starting (or ending) at the quantum critical point. In particular, we analyze the scaling of the excitation probability, number of excited quasiparticles, heat and entropy with the quench amplitude, and the system size. We extend the analysis to quenches with arbitrary power law dependence on time of the...
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In: Physical Review A, 2009, vol. 80, p. 033604
We investigate theoretically the evolution of the two-point density correlation function of a low-dimensional ultracold Bose gas after release from a tight transverse confinement. In the course of expansion thermal and quantum fluctuations present in the trapped systems transform into density fluctuations. For the case of free ballistic expansion relevant to current experiments, we present simple...
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