Doctorant​/doctorante gaz quantiques F​/H H​/F

Quantum Transport In Synthetic Materials

Subject of the thesis:
In the context of the national PEPR Quantique program, the QUTISYM (Quantum transport in synthetic materials) project, which involves a dozen research groups in France, addresses the quantum simulation of transport phenomena. This thesis, funded by this project, is particularly focused on the study of superfluid dynamics of a gas of cold atoms confined to the surface of an immaterial bubble, and in a second phase in an annular guide.

A first part of the thesis will address the out-of-equilibrium dynamics in a quasi-two-dimensional gas, when the atoms are trapped at the bottom of the bubble. Nucleation, organization into a network, disorder, evolution dynamics, and the lifetime of vortices in the rapidly rotating sample will be the subject of the first part of the thesis. A second part of the thesis will be devoted to the experimental setup of an annular trap to enable the study of transport in this geometry where circulation in the ring is quantized.

Context:
The superfluidity of quantum gases was observed shortly after their first realization. Rotating the gas at moderate speeds has notably led to the observation of quantized circulation vortices. The regime of very high rotation speeds gives rise to the observation of vortex networks. Recently, the host team has obtained original results by exploring the regime of rapid rotation in a bidimensional an harmonic trap: the demonstration of a supersonic flow regime and the study of vortex network melting activated by thermal fluctuations.

It has also been illustrated in the study of annular quantum gases. The activity will take place within the Laboratory of Laser Physics, a joint research unit of the University of Sorbonne Paris Nord and the CNRS. The Bose-Einstein Condensates group (group BEC, see (Use the "Apply for this Job" box below).-paris
13.fr) has developed two experiments on the dynamics of quantum gases. One of these two experiments routinely produces a rubidium quantum gas confined in a bubble trap, realized with magnetic fields and radio frequency. The extremely smooth and completely controllable potential geometry that results allows the study of the collective modes of the gas and its controlled rotation. The thesis will be supervised by Hélène Perrin (DR CNRS) and co-supervised by Laurent Longchambon, maître de conférences at the University of Sorbonne Paris Nord.

A research engineer, a research associate, a postdoctoral researcher, and a doctoral student will also be involved in the project, which is funded by the PEPR Quantique program, project QUTISYM. The BEC group further includes a CNRS researcher, another maître de conférence, and a doctoral student, involved mainly on the other experimental device.

Constraints and risks:
Class IV laser: the use of protective glasses is indispensable. Electrical risks: use of high voltage.

• Level Level 8 Doctorate/equivalent degrees
• Specialization General training

• French Threshold