Skip to main content

Leeds-Loughborough-Nottingham Non-Equilibrium Seminars

Following the tradition from the previous years,  the Universities of Leeds (Dr. Papic), Loughborough (Dr. Lazarides) and Nottingham (Dr. Bertini) will be running a joint hybrid seminar series on non-equilibrium physics during 2023/24. "Hybrid" means that some of the seminars will be delivered in person in one of the Universities and broadcast remotely in others, while some seminars will be fully online.

The seminars will be on Zoom and typically take place on Wednesdays at 3pm UK time:

Leeds-Loughborough-Nottingham Zoom Seminar

https://universityofleeds.zoom.us/j/81863636407?pwd=aitNN0pXWmJGSjhUMFFCVnFrSys1Zz09

Meeting ID: 818 6363 6407

Passcode: 1828#Ab

For a complete list of previous seminars in 2020/21, 2021/22 and 2022/23, please see the archive on the left.

Seminar schedule (evolving)

  • 11/11/2023, 3pm: Dr. Ahsan Nazir (University of Manchester)

Location: Room B17, University of Nottingham
Title: Quantum work statistics at strong reservoir coupling.

Abstract: Calculating the stochastic work done on a quantum system while strongly coupled to a reservoir is a formidable task, requiring the calculation of the full eigenspectrum of the combined system and reservoir. In this talk I will show that this issue can be circumvented by using a polaron transformation that maps the system into a new frame where weak-coupling theory can be applied. It is shown that the work probability distribution is invariant under this transformation, allowing one to compute the full counting statistics of work at strong reservoir coupling. Crucially this polaron approach reproduces the Jarzynski fluctuation theorem, thus ensuring consistency with the laws of stochastic thermodynamics. I will apply the formalism to a system driven across the Landau-Zener transition, where clear signatures in the work distribution arising from a non-negligible coupling to the environment are identified. These results provide a new method for studying the stochastic thermodynamics of driven quantum systems beyond Markovian, weak-coupling regimes.

O. Diba, H. J. D. Miller, J. Iles-Smith, and A. Nazir, arXiv:2302.08395

 

  • 25/10/2023, 3pm: Dr. Mark Mitchison (Trinity College Dublin)

Location: Sir William Henry Bragg Building 4.03, University of Leeds
Title: Current fluctuations in continuously measured quantum systems: lessons from the critical Kerr model.
Abstract: Continuously measured quantum systems are characterized by an output current, in the form of a stochastic and correlated time series which conveys crucial information about the underlying quantum system. In this talk, I will present a toolbox for describing current fluctuations, which unifies concepts from continuous measurement theory and full counting statistics [1]. As an application, I will discuss current fluctuations in the parametrically pumped Kerr (PPK) model. The PPK model describes a driven-dissipative nonlinear cavity, whose nonequilibrium phase diagram features both continuous and discontinuous quantum phase transitions. When continuously measuring light leaking from the cavity, the photocurrent shows interesting divergences near criticality, whose nature depends both on the order of the phase transition and the choice of measurement basis [2]. These findings highlight the rich features of current fluctuations near nonequilibrium phase transitions in quantum-optical systems. Time permitting, I will also provide an outlook on some interesting future directions related to strongly coupled transport problems [3,4] and the thermodynamics of clocks [5,6].[1] G. T. Landi, M. J. Kewming, M. T. Mitchison & P. P. Potts, arXiv:2303.04270[2] M. J. Kewming, M. T. Mitchison & G. T. Landi, Phys. Rev. A 106, 033707 (2022)[3] M. Brenes et al., Phys. Rev. X 10, 031040 (2020)[4] A. M. Lacerda et al., Phys. Rev. B 107, 195117 (2023)[5] P. Erker et al., Phys. Rev. X 7, 031022 (2017)[6] O. Culhane et al., arXiv:2307.09122