2023-24-project-catalogue

###Polariton and circuit QED lattices: quantum simulations of correlated and topological states

Project ID: 2228bd1150 (You will need this ID for your application)

Research Theme: Physical Sciences

UCL Lead department: Physics and Astronomy

Department Website

Lead Supervisor: Marzena Szymanska

Project Summary:

Applications are invited for a 4-year PhD project in theoretical Condensed Matter/AMOPP Physics under the supervision of Prof Marzena Szymanska and in collaboration with world leading experimental groups in UK, USA, France and Israel.

The aim of the project is to explore the recently emerged solid-state platforms, that of polariton lattices and superconducting qubits, and to optimise them for the holy grails of quantum simulations: correlated regime and topological protection.

Ever since the original proposal for the idea of quantum simulations, the search for suitable physical platforms and their improvement has been one of the most active and successful fields of research.

We aim at developing techniques to study correlated and topological effects in conditions of drive, dissipation and non-equilibrium in collaboration with experimental groups following one or more of the below:

• Extension of stochastic phase space methods developed for driven-dissipative bosonic systems to spin systems and to account for strong correlations and entanglement;

• Analytical methods: mean-field approximation, Keldysh Field theory, Renormalisation Group;

• Development of tensor network methods for driven-dissipative systems.

We will explore the following systems:

• Polariton Lattices: phase transitions and topological defects in weak lattices of Surface Acoustic Waves, exotic quantum correlations in chains and lattices of polariton micro-pillars;

• Circuit QED lattices: collective effects in many-spin-cavity systems and lattices, symmetry protected topological states in spin systems with short- and long-range interactions.

And the following phenomena:

• The non-equilibrium phase transitions, orders, critical properties, topological defects, non-trivial topological states in driven-dissipative but strongly interacting polariton (bosonic) and circuit QED (spin-boson) lattices.

• The formation and the propagation of entanglement, its robustness to dissipation, and design of settings to optimise the quantum correlations and entanglement in open systems using chains of polariton micro-pillars and of superconducting qubits.