engleski

Loschmidt echo in one-dimensional interacting Bose gases

We explore Loschmidt echo in two regimes of one- dimensional interacting Bose gases: the strongly interacting Tonks-Girardeau (TG) regime, and the weakly interacting mean-field regime. We find that the Loschmidt echo of a TG gas decays as a Gaussian when small (random and time independent) perturbations are added to the Hamiltonian. The exponent is proportional to the number of particles and the magnitude of a small perturbation squared. In the mean-field regime the Loschmidt echo shows richer behavior: it decays faster for larger nonlinearity, and the decay becomes more abrupt as the nonlinearity increases ; it can be very sensitive to the particular realization of the noise potential, especially for relatively small nonlinearities.

Loschmidt echo; irreversibility; nonequilibrium dynamics

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