Open quantum dynamics of strongly coupled oscillators with multi-configuration time-dependent Hartree propagation and Markovian quantum jumps

TL;DR

This paper introduces a hybrid quantum trajectory method combining stochastic quantum jumps with MCTDH wavefunction propagation to efficiently simulate the dissipative dynamics of strongly coupled quantum oscillators, applicable to complex many-body systems.

Contribution

It develops a novel hybrid approach integrating quantum jumps and MCTDH for modeling open quantum systems with strong interactions and high excitations.

Findings

Accurate results for cavity QED systems using fewer trajectories.

Efficient simulation of large, strongly interacting oscillator arrays.

Potential to handle high excitation densities in dissipative quantum dynamics.

Abstract

Modeling the non-equilibrium dissipative dynamics of strongly interacting quantized degrees of freedom is a fundamental problem in several branches of physics and chemistry. We implement a quantum state trajectory scheme for solving Lindblad quantum master equations that describe coherent and dissipative processes for a set of strongly-coupled quantized oscillators. The scheme involves a sequence of stochastic quantum jumps with transition probabilities determined the system state and the system-reservoir dynamics. Between consecutive jumps, the wavefunction is propagated in coordinate space using the multi-configuration time-dependent Hartree (MCTDH) method. We compare this hybrid propagation methodology with exact Liouville space solutions for physical systems of interest in cavity quantum electrodynamics, demonstrating accurate results for experimentally relevant observables using a tractable number of quantum trajectories. We show the potential for solving the dissipative dynamics of finite size arrays of strongly interacting quantized oscillators with high excitation densities, a scenario that is challenging for conventional density matrix propagators due to the large dimensionality of the underlying Hilbert space.