Quantum electron-vibrational dynamics at finite temperature: Thermo field dynamics approach

Abstract

Quantum electron-vibrational dynamics in molecular systems at finite temperature is described using an approach based on the thermo field dynamics theory. This formulation treats temperature effects in the Hilbert space without introducing the Liouville space. A comparison with the theoretically equivalent density matrix formulation shows the key numerical advantages of the present approach. The solution of thermo field dynamics equations with a novel technique for the propagation of tensor trains (matrix product states) is discussed. Numerical applications to model spin-boson systems show that the present approach is a promising tool for the description of quantum dynamics of complex molecular systems at finite temperature.

Thermofield Theory for Finite-Temperature Coupled Cluster

“…Undoubtedly, TFD has the potential to study manyelectron systems in quantum chemistry and condensedmatter physics. [43][44][45][46][47][48][49][50][51] A connection between thermofield formalism and thermal cluster-cumulant theory was also explored by Mukherjee et. al.…”

Thermal Schrödinger Equation: Efficient Tool for Simulation of Many‐Body Quantum Dynamics at Finite Temperature

“…An explicit expression for in the linear vibronic‐coupling representation of the original Hamiltonian can be found in Ref. [].…”

“…At room temperature, they require a statistical sampling of the initial conditions followed, in some procedures, by a double propagation in real and imaginary time . Recently, we have suggested an alternative and computationally efficient wave‐function‐based method for the simulation of time‐dependent properties of quantum systems with many degrees of freedom at finite temperature . The method is based on the ideas of Thermo Field Dynamics (TFD), which was introduced in the 1970's to provide a finite temperature representation of quantum mechanics.…”

“…The analysis of Ref. [] was restricted to a system consisting of several discrete (electronic) states linearly coupled to multiple bosonic (vibrational) degrees of freedom, and the Hamiltonian of the system was considered to be time‐independent. The present work lays theoretical foundation for the extension of the method towards arbitrary quantum systems described by time‐dependent (driven) Hamiltonians.…”

Zeno effect of an open quantum system in the presence of 1/f noise

“…By increasing the system-environment coupling strength, we observe a novel transition from a pure QZE to a crossover of QZE-QAZE at zero temperature. Moreover, We generalized our study to the finite temperature case by combining the MPS-TDVP method with the so-called thermo field dynamics method(TFD) which has been used recently in the study of electron-vibrational dynamics [30,31]. We find that the thermal fluctuations raise an additional suppression of decay of the survival probability in the short time regime, whereas it enhances the decay rate in long time scale.…”