-Preparation of spin-noise compressed states
-Implementation of optimum pulse protocols for a microwave clock with trapped atoms
-Implementation of clock sequences (Ramsey interferometer)
-Characterization of the stability of an atomic clock on an atom chip

This offer concerns a second generation of experiments evaluating the contribution of non-classical entangled states to improving the stability of atomic clocks. Compressed-spin states redistribute the fundamental quantum noise of the atomic phase to a conjugate variable of secondary interest. This overcomes the fundamental limit of the signal-to-noise ratio of today's best clocks. The principle of improvement has been demonstrated by several teams around the world, but no instrument has yet reached the performance level of a real clock. Our aim is to improve, for the first time, a state-of-the-art atomic clock. In our experiment, carried out in collaboration with Laboratoire Kastler Brossel, a fiber-optic microcavity is installed on an atom chip to prepare and detect compressed spin states. State tomography of the spin distribution will be used to quantify noise reduction. Comparison of the clock with and without squeezing will enable us to assess the performance gain. The expected results have the potential to place TACC ahead of the best compact clocks currently known. In addition, the tools for manipulating entangled states are likely to find applications in other fields such as quantum computing. In the course of his/her work, the candidate will participate in the assembly of the modules (optical, mechanical, electronic, etc.) required for the experiments described above. The candidate will also be in charge of data acquisition and analysis. An important task will be to evaluate the systematics involved in the spin squeezing generation step and its influence on the clock's relative frequency instability. He/she will be part of a team including a PhD student, and will interact with members of the LTE Atomic Interferometry and Inertial Sensors team, as well as with members of the LKB Atom Chips team.

The “Atomic Interferometry and Inertial Sensors” team at LTE is headed by Franck Pereira Dos Santos. Its aim is to study the possibilities offered by atomic interferometry for high-precision measurements, and in particular for the production of very high-performance inertial sensors. Our team is a pioneer in the development of these sensors, with internationally recognized expertise in instrument metrology. In particular, we demonstrated the first cold atom gyrometer, were the first team to take part in international comparison campaigns of absolute gravimeters with our atomic gravimeter, and demonstrated the dead-time-free operation of this type of sensor. Our many contributions to the field (models for assessing sensitivity and accuracy limits, development of vibration rejection techniques, demonstration of new sensor architectures, development of hybridization methods, etc.) are now widely adopted by other teams. Our work in gravimetry has led to an industrial transfer to Muquans, which markets cold atom gravimeters based on patented technology.