Full Counting Statistics of Heat and Work in the Non-Markovian Regime

Abstract

Coherent control of quantum systems - the foundation of all quantum technologies - is made difficult by the fact that all quantum systems are open. Interactions with an external environment lead to decoherence and dissipation of quantum systems, which is a problem if we want to manipulate these systems in order to perform useful operations. In order to control these systems we must supply them with energy, or in the language of thermodynamics, we must ‘do work’ on them, and interactions with the environment leads to heat dissipation or absorption. Being ‘path functions’, work and heat are stochastic at the quantum scale, meaning they must be defined through a probability distribution. This thesis develops novel techniques to calculate the statistics of the probability distributions of heat and work transfer for open quantum systems strongly coupled to non-Markovian environments. By combining the reaction coordinate mapping and the two point measurement protocol we develop a theory that can track the statistics of heat flow and work transfer for a two-level system coupled to a bath of bosons. Additionally, we combine process tensor theory with the two point measurement protocol, allowing us to develop a novel, numerically exact, method of calculating work statistics for a driven open quantum system that does not rely on any approximations about the underlying physics.

Date of Award	4 Feb 2025
Original language	English
Awarding Institution	University of Bristol
Supervisor	Ahsan Nazir (Supervisor) & Jake Iles-Smith (Supervisor)