Ivander, F; Lindoy, L P; Lee, J (2024) Unified Framework for Open Quantum Dynamics with Memory. Nature Communications, 15. 8087

Preview

Text eid10074.pdf - Published Version Available under License Creative Commons Attribution. Download (1MB) | Preview

Abstract

We present an analytic relationship between the Nakajima-Zwanzig memory kernel (K) and the influence functions (I), which are two prevalent frameworks to study open quantum dynamics with memory (i.e., non-Markovian dynamics). We start from the discretized Feynman-Vernon path integral formulation, then express the system propagator (U) as a function of I and finally relate U to K. Based on this, we propose a non-perturbative, diagrammatic approach to construct K from I for (driven) systems interacting with harmonic baths without the use of any projection-free dynamics inputs required by standard approaches. With this construction, we also show how approximate path integral methods can be understood in terms of approximate memory kernels. Furthermore, we demonstrate a Hamiltonian learning procedure to extract the bath spectral density from a set of reduced system trajectories obtained experimentally or by numerically exact methods, opening new avenues in quantum sensing and engineering. The insights we provide in this work will significantly advance the understanding of non-Markovian dynamics, and they will be an important stepping stone for theoretical and experimental developments in this area.

Item Type:	Article
Keywords:	Open Quantum System Dynamics, Influence Functional, Memory Kernel
Subjects:	Mathematics and Scientific Computing > Numerical Computation
Divisions:	Quantum Technologies
Identification number/DOI:	10.1038/s41467-024-52081-3
Last Modified:	18 Oct 2024 13:14
URI:	https://eprintspublications.npl.co.uk/id/eprint/10074