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Reference : UMR8552-NICCHE-002
Workplace : PARIS 05
Date of publication : Tuesday, June 8, 2021
Type of Contract : FTC Scientist
Contract Period : 12 months
Expected date of employment : 1 October 2021
Proportion of work : Full time
Remuneration : 2728 à 3881 euros gross salary depending on experience
Desired level of education : 5-year university degree
Experience required : 1 to 4 years
When perturbed from an equilibrium situation, isolated interacting quantum systems experience a more or less complicated temporal evolution and generically return to equilibrium at sufficiently long time. For non-integrable systems, this final state is usually characterized by a statistical thermal ensemble. This dynamical process arises in the absence of any external temperature "bath'', the interacting system itself serving as a bath for all its subparts. The dynamics leading to the thermal state can be very rich, associated with a variety of intriguing phenomena such as a transient pre-thermal regime or universal self-similarity properties of its correlations function to give a few examples. In driven quantum systems, the situation is in general different because the external forcing tends to drive the system toward a thermal state of infinite temperature. In this context, special attention has recently been paid to the possibility to thermalize a driven quantum system to a finite temperature using spatial or temporal disorder.
The goal of this post-doctoral project is to theoretically investigate the out-of-equilibrium dynamics of a one-dimensional periodically-driven system known as the quantum kicked rotor. This paradigm of quantum chaos describes a collection of particles periodically kicked by a stationary-wave external force and has played an important role in the context of Anderson localization of cold atoms. During the project, we plan to study the role of interactions in this system, in specific configurations where the kicked rotor is likely to thermalize to a finite temperature. In detail, we will first explore the low-energy regime where the particles are weakly kicked so that a non-equilibrium pre-thermal regime may occurs at short time. After this preliminary step, we will address the more general question of thermalization in the mixed regime where chaotic areas coexist with more regular regions in the phase space.
- Describe theoretically and numerically the out-of-equilibrium quantum dynamics of the kicked-rotor in a weakly kicked, chaotic regime
- Explore theoretically and/or numerically thermalization in the mixed regime
The candidate should have a knowledge of the non-equilibrium physics of quantum systems and the associated numerical and theoretical approaches. An expertise of chaotic systems would be a strong asset. The recruited postdoc will be a highly dynamic, motivated and positive, and able to regularly communicate with the team.
Joint research unit of the École normale supérieure, Sorbonne University, the Collège de France and the National Center for Scientific Research (CNRS), the Kastler Brossel Laboratory (LKB) is one of the major players in the field of quantum physics. It covers many topics ranging from fundamental tests of quantum physics to their applications. Its expertise is internationally recognized as evidenced by its three Nobel Prizes obtained over its 65 years of history.
The work of the Postdoctoral researcher will be supervised by Dr. Nicolas Cherroret in the Complex Quantum Systems group of LKB, and it will be carried out within the framework of the project "MANYLOK" funded by the ANR. It will involve both analytical and numerical approaches.
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