I have an opening for a master M2 internship project at the IPhT, CEA-Saclay for the academic year 2017/18. See below for potential subjects and topics . If you are interested please contact me directly at email@example.com
Stage 1: Driven-Dissipative Quantum Light Matter Systems
Experimental progress in coupling light and matter at the quantum level achieved with cavity-Quantum Electrodynamics (CQED) has brought forth new platforms for many body quantum optics, where light and matter play equally important roles in collective quantum behavior. Examples include microcavity exciton-polaritons showing non-equilibrium superfluidity, arrays of coupled CQED cavities hosting correlated states of light, such as the driven-dissipative Mott insulator of polaritons. From a theoretical perspective CQED arrays can be described by models of interacting bosons in presence of both external driving fields and dissipation mechanisms, representing unavoidable particle losses, dephasing and decoherence processes and which are naturally described in terms of many-body Lindblad Master Equations for the system density matrix. The crucial aspect of the problem lies in the balance between unitary (drive) and dissipative (losses) evolution, out of which non trivial stationary and transient states are expected to emerge as well as novel classes of dynamical and dissipative quantum phase transitions. The goal of this master project is to investigate models of driven and dissipative quantum light matter systems using a combination of analytical and numerical techniques.
Stage 2: Flow Equation Approaches for Disordered Quantum Systems Out of Equilibrium
Quenched random disorder can have dramatic effects on transport and dynamical properties of quantum many-body systems, leading to a complete breakdown of diffusion and to the localized non-ergodic behavior of a non-interacting quantum particle in a random external potential, as first predicted by Anderson. For long times it was thought that such a localized phase would have not survived in presence of finite interaction and finite excitation energy(temperature); the recent theoretical and experimental discovery of Many Body Localization (MBL) therefore came as a surprise. MBL is a new quantum phase of matter where thermalization and equilibration break down due to strong disorder, resulting in a number of remarkable non equilibrium properties. We have recently developed a flow-equation approach to describe static and dynamical properties of MBL phases and the goal of this master project is to use and extend further this technique to different settings, including generic time dependent problems, periodically driven systems, dissipative systems.
Stage 3: Periodically Driven Quantum Many Body Systems
Recent years have seen tremendous progress in the control and manipulation of quantum phases of matter with external driving fields. Notable examples include light-induced superconductivity, or the realization of a topological Haldane phase with ultra cold atoms. From a theoretical perspective, investigations on driven quantum systems, so called “Floquet” problems, have a long tradition but until recently they were mostly focused on single-particle problems. The interest toward genuine many body, strongly interacting realizations of these settings has grown in the past few years and several non trivial dynamical phenomena are expected to emerge due to the competition between interaction and drive. The goal of this master project is to investigate models of periodically driven strongly correlated electrons, such as the Fermi Hubbard model, using a combination of analytical and numerical techniques.