Fourier transformation of propagating of coherent states in octupole perturbed potential

S. Hasanijafari, Sajjad Parsamehr

Li, Jun-qing, Liu +1 more

Theoretical Nuclear PhysicsA coherent state is a well localized wave packet, its width in phase space satisfies the minimum uncertaintyprinciple, and it moves along classical trajectories. The coherent state of two dimensional axially symmetricharmonic oscillator in a potential with additional octup

A. D. Jannussis, V. Papatheou, N. Patargias +1 more

Peter Woit

Wen-ge Wang, Baowen Li

We study the crossover of the quantum Loschmidt echo (or fidelity) from the golden-rule regime to the perturbation-independent exponential decay regime by using the kicked top model. It is shown that the deviation of the perturbation-independent decay of the averaged fidelity from the Lyapunov decay results from quantum fluctuations in individual fidelity, which are caused by the coherence in the initial coherent states. With an averaging procedure suppressing the quantum fluctuations effectively, the perturbation-independent decay is found to be close to the Lyapunov decay. We also show that the Fourier transform of the fidelity is determined directly by the initial state and the eigenstates of the Floquet operators of the two classically chaotic systems concerned. The absolute value part and the phase part of the Fourier transform of the fidelity are found to be divided into several correlated parts, which is a manifestation of the coherence of the initial coherent state. In the whole crossover region, some important properties of the fidelity, such as the exponent of its exponential decay and the short initial time within which the fidelity almost does not change, are found to be closely related to the properties of the central part of its Fourier transform.

B.V. Samsonov