Enhanced TEMPO algorithm for quantum path integrals with off-diagonal system-bath coupling: applications to photonic quantum networks

TL;DR

This paper extends the enhanced TEMPO algorithm for quantum path integrals to handle off-diagonal system-bath couplings, enabling more accurate simulations of complex quantum systems like coupled cavity waveguides and applications in quantum optics.

Contribution

The paper introduces an extension of the TEMPO algorithm to include off-diagonal system-bath interactions, broadening its applicability to more complex quantum systems.

Findings

Successfully applied to a coupled cavity waveguide system with separated quantum emitters

Demonstrates potential for applications in quantum optics and material science

Enables simulation of entangled photon propagation and photosynthesis spectroscopy

Abstract

Multitime system correlations functions are relevant in various areas of physics and science, dealing with system-bath interaction including spectroscopy and quantum optics, where many of these schemes include an off-diagonal system bath interaction. Here we extend the enhanced TEMPO algorithm for quantum path integrals using tensor networks [Phys. Rev. Lett. 123, 240602 (2019)] to open quantum systems with off-diagonal coupling beyond a single two level system. We exemplify the approach on a coupled cavity waveguide system with spatially separated quantum two-state emitters, though many other applications in material science are possible, including entangled photon propagation, photosynthesis spectroscopy and on-chip quantum optics with realistic dissipation.