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Institut for Fysik og Astronomi CCQ

CCQ/CQOM Colloquium - Yanhong Xiao, Fudan University, Shanghai: Non-Hermitian quantum optics and quantum metrology with large ensemble of room-temperature atoms

Oplysninger om arrangementet


torsdag 13. januar 2022,  kl. 10:00 - 11:00



Room-temperature atoms in glass vapor cells form a large ensemble and a unique platform for research in quantum optics and quantum metrology. Using “flying” atoms in a vapor cell as the information carrier of light, we show that non-Hermitian Hamiltonian can be realized for spatially-channelized EIT (and associated spin waves) under dissipative coupling. Anti-parity-time symmetry was observed, with its exceptional point critically affecting both the EIT resonance frequency and the quantum correlations between spatially separated laser beams. Furthermore, the atomic-reservoir outside the EIT channels, as well as the laser beam array geometry and the multi-level atom-light interaction can be engineered for complex coupling, non-reciprocal light transport, topology and novel quantum light sources. Then, in the second part of the talk, I will describe how we spin squeeze 100 billion atoms in a wall-coated vapor cell and apply it for femto-Tesla-level magnetometry surpassing the standard quantum limit. Finally, prospects of the current research will be discussed.