Semiclassical Density Matrix Near the Top of a Barrier
F. J. Weiper, J. Ankerhold, H. Grabert
Abstract
Employing the path integral approach, we calculate the semiclassical equilibrium density matrix of a particle moving in a nonlinear potential field for coordinates near the top of a potential barrier. As the temperature is decreased, near a critical temperature Tc the harmonic approximation for the fluctuation path integral fails. This is due to a caustic arising at a bifurcation point of the classical paths. We provide a selfconsistent scheme to treat the large quantum fluctuations leading to a nonlinear fluctuation potential. The procedure differs from methods used near caustics of the real time propagator. The semiclassical density matrix is determined explicitly for the case of asymmetric barriers from high temperatures down to temperatures somewhat below Tc. Pacs: 03.65.Sq, 05.30.-d
Create a lesson
Related papers
Spectral Fingerprints of Gauge Theories on a Quantum Computer
Graham Van Goffrier, Debasish Banerjee, Bipasha Chakraborty et al.
Dynamics of local quantum information in random unitary circuits
Ratul Thakur, Sthitadhi Roy
Factorized Boolean representations for efficient quantum synthesis
Mehul Shah, Robert Fiszer, Marek Perkowski
Detuning- and Stark-robust Rydberg gates
Elie Bataille, Gyohei Nomura, Manuel Endres
Krylov Break Times from an Inhomogeneous Lieb--Robinson Light Cone
Shunji Matsuura, Yoji Kawamura, Joseph Salfi et al.
Stochastic transport of a Goldstone mode in a self-organized atomic crystal
Zhanhai Yu, Di Xiang, Xiaotian Zhang et al.