Supervisors:

Dr Katarzyna Macieszczak (Phys.) Prof. David Quigley, (Phys. and Scientific Computing Research Technology Platform)

Summary:

Future quantum technologies rely on preparation and manipulation of quantum systems, but current setups can achieve only limited control. Improving on this requires modelling these experiments, but number of configurations and long timescales [1] inhibits exact numerical approaches. We will circumvent the former by exploiting symmetries in collective open quantum dynamics [2,3] for simulations of hybrid systems in quantum optics [4], and by modifying rare events techniques [5], we will avoid the latter. We will further use dimensional reduction [6] to identify and model [7] phase transitions in experiments. We aim to propose and verify new experimental settings that could support such phenomena.

Background:

This project will be an excellent fit for a student looking to contribute to development of cutting-edge numerical tools and interested in working at the very overlap of quantum information science with non-equilibrium physics in pursuit of emergent quantum phenomena [1].

We will study these systems using the quantum jump Monte Carlo method and improve upon the state of the art by utilising symmetries [2,3,4] and large deviation techniques [5] to efficiently generate quantum trajectories in parallel simulations. Uncertainty quantification will be used to verify new experimental settings. Proxy models will be constructed by adapting dimensionality reduction techniques to quantum rather than classical stochastic dynamics, using data obtained in earlier simulations [6,7].

We aim to investigate permutationally symmetric atomic systems interacting with continuously monitored optical environments, in close relation to experimental settings where large ensembles can be controlled in a feasible manner. Both average and other ensemble properties are to be uncovered for quantum technology applications and in the context of dissipative phase transitions.

Relevant references:

[1]	K. Macieszczak, D. C. Rose, I. Lesanovsky, J. P. Garrahan, Phys. Rev. Research 3, 033047 (2021), K. Macieszczak, M. Guţă, I. Lesanovsky, J. P. Garrahan, Phys. Rev. Lett. 116, 240404 (2016).
[2]	K. Macieszczak, D.C. Rose, Phys. Rev. A 103, 042204 (2021).
[3]	Y. Zhang, Y.-X. Zhang, and K. Mølmer, New. J. Phys., 20, 112001 (2018).
[4]	N. Shammah, S. Ahmed, N. Lambert, S. De Liberato, and F. Nori., Phys. Rev. A 98, 063815 (2018).
[5]	F. Carollo, C. Pérez-Espigares, Phys. Rev. E 102, 030104 (2020).
[6]	A. Sornsaeng, N. Dangniam, P. Palittapongarnpim, T. Chotibut, Phys. Rev. A 104, 052410 (2021).
[7]	H. Vroylandt, L. Goudenège, P. Monmarché, B. Rotenberg, Proc. Nat. Acad. Sci. 119 (13) e211758611 (2022).