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Non-markovian quantum brownian motion.

Werren, Nicholas (2020) Non-markovian quantum brownian motion. Doctoral thesis, University of Surrey.

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Abstract

We develop a non-Markovian extension to the caldeira-leggett master equation for quantum Brownian motion by using the timescale of the bath as a small parameter around which to perform a perturbative expansion. This framework allows us to deal directly with the time non-locality of the non-Markovian regime. We derive an exact description of the evolution of the reduced density matrix and obtain a new quantum master equa- tion with non-Markovian corrections added perturbatively to the standard Lindblad form. The resulting simulations show new dynamics and a strong deviation from Markovian behaviour. We observe that quantum coherences survive far longer than in the Marko- vian limit. In particular, when the system is fully non-Markovian, quantum phenomena experience a form of decoherence that behaves functionally like an inverse-power law. These results may have important implications in quantum technologies and biology as they suggest environments can be engineered to support long-lived quantum coherence.

Item Type: Thesis (Doctoral)
Divisions : Theses
Authors : Werren, Nicholas
Date : 30 June 2020
Funders : STFC, University of Surrey, Department of Microbial Sciences, University of Surrey, Department of Physics
DOI : 10.15126/thesis.00856962
Contributors :
ContributionNameEmailORCID
http://www.loc.gov/loc.terms/relators/THSRocco, AndreaA.Rocco@surrey.ac.uk
http://www.loc.gov/loc.terms/relators/THSAl-Khalili, JimJ.Al-Khalili@surrey.ac.uk
Uncontrolled Keywords : Memory, effects, quantum, biology, physics, doctoral research training centre, surrey, rocco, al-khalili, werren
Depositing User : Nicholas Werren
Date Deposited : 09 Jul 2020 15:16
Last Modified : 09 Jul 2020 15:17
URI: http://epubs.surrey.ac.uk/id/eprint/856962

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