The correlation function for a quantum oscillator in a low-temperature heat bath |
| |
Institution: | 1. Department of Physics, University of Abomey-Calavi, Benin;2. Institute of Mathematic and Physical Sciences (IMSP), Benin;3. Department of Physics, Erciyes University, Kayseri 38039, Turkey;1. School of Computer Science, University of Birmingham, Birmingham B15 2TT, UK;2. Helsinki Institute for Information Technology, Department of Computer Science, Aalto University, Finland;3. School of Computer Science, University of Appl. Sc. Wuerzburg-Schweinfurt, Wuerzburg 97074, Germany |
| |
Abstract: | The momentum autocorrelation function c(t) for a quantum oscillator coupled with harmonic forces to a heat bath of oscillators is calculated at low temperatures. It is found that c(t) contains two distinct terms: one, the zero-point contribution c0(t), is temperature independent, and the other, c1(t), does depend on temperature. We concentrate our attention on the low-temperature case. An expression for c1(t) is obtained, which is valid for arbitrary strenghts of the coupling and for arbitrary times. It is shown that c1(t) is governed by the low-frequency behaviour of F(λ) = A2(λ)ϱ(λ), where ϱ(λ) is the density of normal modes and A(λ) is the central-oscillator component of the λth normal mode; other details of the problem are irrelevant. It is found that c1(t) decays in time as an inverse-power law, with a relaxation time tq ≈ ħ/kT. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|