Research
Theoretical physicist specialising in open quantum systems: how quantum systems exchange energy with, and lose coherence to, their environment.
PhD thesis
Fluctuation-Dissipation Relations in Open Quantum Systems, University of Surrey. Supervisors: Dr Andrea Rocco and Prof Jim Al-Khalili. Funded by the Leverhulme Quantum Biology Doctoral Training Centre. Submitted August 2026; viva passed 2 November 2026, with minor corrections.
- Derived a new open-system model in which each environmental oscillator is itself an open quantum system.
- Tested quantum fluctuation-dissipation relations across four open-system models, and showed that two non-Markovian extensions of the Caldeira-Leggett model relax to an effective temperature above that of their environments.
- Extended the exact method-of-characteristics solution of the Caldeira-Leggett master equation to further dissipation and decoherence terms, and derived higher-order generalised Kubo response formulae.
- Modelled decoherence and tunnelling between the wells of a double-well potential, motivated by proton transfer in DNA.
The full thesis will be available here once the corrections are approved.
Publications
- L. Buxton, M.-T. Russo, J. Al-Khalili, and A. Rocco, “Quantum Brownian Motion in the Caldeira-Leggett Model with a Damped Environment”, arXiv:2303.09516 (2023). Preprint; revised version in preparation.
- M.-T. Russo, J. Al-Khalili, and A. Rocco, “Embedded Ohmic Environments”. In preparation.
Earlier research
MSc dissertation, King's College London, supervised by Prof Joe Bhaseen: Exploring Non-Equilibrium Dynamics on Quantum Computers. Over 1,000 jobs on IBM's five-qubit Santiago device, identifying the trade-off between Trotter and two-qubit gate errors.
Interests
- Open quantum systems
- Non-equilibrium statistical mechanics
- Fluctuation-dissipation relations
- Quantum biology
- Quantum simulation