Quantum Langevin dynamics and the long-time behaviour of two charged coupled oscillators in a common heat bath

TL;DR

This paper investigates the long-time behavior of two charged coupled oscillators in a heat bath under a magnetic field, revealing power law decay of correlations at zero temperature and the influence of magnetic fields on dynamics.

Contribution

It introduces a detailed analysis of quantum Langevin dynamics for coupled oscillators in a magnetic field, highlighting how magnetic effects alter correlation decay and bath-induced forces.

Findings

Correlation functions decay as a power law at zero temperature.

Magnetic fields increase correlation functions and slow decay.

Results are relevant for atomic movements in low-temperature proteins.

Abstract

In this paper, the moderately long-time behaviours of the correlation functions for two charged coupled harmonic oscillators connected to a common heat bath are analyzed in the presence of a magnetic field via the Quantum Langevin dynamics. Interestingly it is seen that at long times the correlation functions at $T \rightarrow 0$ exhibit a power law decay with the coefficients of the power laws being completely different for the two masses, affecting the overall dynamics of the coupled system. The effect of the bath-induced force on mass m1 mediated by the interaction of m2 with the common heat bath is studied and the results are highlighted in the presence of an external magnetic field. It is shown that the effect of cyclotron frequency increases the correlation functions at an instant of time, lowering the rate of temporal decay of the correlation functions. The results in the absence of a magnetic field are also presented, which are extremely important for investigating the movements of the atoms in protein molecules at low temperatures.