PhD on Dipole Blockade with superconducting atom chips

Laboratoire Kastler Brossel, Ecole Normale supérieure, 24 rue Lhomond 75005 Paris France

A superconducting atom chip for a deterministic source of Rydberg atoms

The work will aim at the realization of a deterministic source of circular Rydberg atoms based on the dipole blockade mechanism in the frame of microwave Cavity Quantum Electrodynamics. Circular Rydberg atoms and superconducting cavities are remarkable tools for the exploration of basic quantum phenomena. A deterministic individual atom source will remove the last bottleneck for the realization of complex quantum information processing sequences.

The first objective is to investigate the dipole blockade mechanism in a dense, small sample of ground state atoms. Due to the very strong dipole-dipole interaction between two Rydberg atoms, the laser excitation frequency for preparing two atoms in the sample is noticeably shifted with respect to that of the first excitation. The resonant laser excitation of a small cloud of atoms is thus bound to result in the deterministic preparation of a single Rydberg atom. The proper conditions for the observation of the dipole blockade mechanism are met with atoms on a superconducting atom chip. A few hundred atoms can be trapped in a Ioffe-Pritchard trap, with transverse dimensions below 1 µm and a length of a few µm.

The first part of the work will be to optimize the chip design to get a trapped atom cloud with the proper shape. We will then perform detailed laser spectroscopy of the Rydberg line in the trap. We will be able to assess the influence of stray electric fields (encouraging preliminary results show that they should not be a problem). We will then look for spectral evidence of the dipole-dipole interaction.

We will next investigate the dipole blockade mechanism. A high efficiency field-ionization detector will be used to count the number of Rydberg atoms prepared and to measure the performance of the deterministic source.

Job description

You will be involved in all experimental and theoretical aspects of our research. You will be in charge of the laser system for atom cooling and trapping, of the micro-fabrication of the atom chips, of the operation, of the cryogenic system and of the realization of the necessary data acquisition software. On the theoretical side, you will have opportunities to explore various applications of dipole blockade in cold atomic samples.


You have a diploma in physics, with an emphasis on atomic physics and quantum optics. Prior experience in a research laboratory is not mandatory, but will be helpful, particularly when in the field of laser and cold atoms physics. Prior knowledge of French is not required, but you should be prepared to take courses in French to facilitate your integration in the laboratory.

About Laboratoire Kastler Brossel

This work will be performed in the Cavity Quantum Electrodynamics group of Laboratoire Kastler Brossel, in the Physics department of Ecole Normale supérieure. The lab is located in the heart of Paris and provides a remarkable scientific environment for a PhD student. It gathers about 150 researchers working on a wide variety of subjects, with a strong emphasis on quantum optics and cold atoms physics. The Laboratory is located in the physics department of Ecole Normale superieure, gathering four other laboratories covering basically all fields of fundamental physics, with more than 400 researchers. The scientific life is thus particularly active, with many seminars and lectures to which you will be able and encouraged to participate.

Send CV, statement of purpose and reference letter (English or French) to be emailed to Pr. Jean-Michel Raimond