Petitjean Cyril, Bevilaqua Diego V, Heller Eric J, Jacquod Philippe
Département de Physique Théorique, Université de Genève, CH-1211 Genève 4, Switzerland.
Phys Rev Lett. 2007 Apr 20;98(16):164101. doi: 10.1103/PhysRevLett.98.164101. Epub 2007 Apr 18.
Motivated by neutron scattering experiments, we investigate the decay of the fidelity with which a wave packet is reconstructed by a perfect time-reversal operation performed after a phase-space displacement. In the semiclassical limit, we show that the decay rate is generically given by the Lyapunov exponent of the classical dynamics. For small displacements, we additionally show that, following a short-time Lyapunov decay, the decay freezes well above the ergodic value because of quantum effects. Our analytical results are corroborated by numerical simulations.
受中子散射实验的启发，我们研究了在相空间位移后通过完美时间反演操作重建波包的保真度衰减情况。在半经典极限下，我们表明衰减率通常由经典动力学的李雅普诺夫指数给出。对于小位移，我们还表明，在经历短时间的李雅普诺夫衰减之后，由于量子效应，衰减在远高于遍历值的情况下冻结。我们的分析结果得到了数值模拟的证实。
