Tue April 16, 2024 4:00 pm
CUA Seminar: Yanhong Xiao – Concurrent spin squeezing and field tracking with machine learning
Location:MIT 4-270
Yanhong Xiao,
Fudan University
Ten Minute Talk:"EngageCUA Launch (Abigail McClain Gomez, Michael Szurek, Simone Notarnicola)"
Squeezing and entanglement play crucial roles in quantum metrology. Yet, demonstrating quantum enhancement in continuous signal tracking remains a challenging endeavor, because entanglement generation and signal perturbations are often incompatible. We show that concurrent steady-state spin-squeezing and sensing are possible using continuous quantum nondemolition measurements under constant optical pumping. We achieved a sustained spin squeezed state containing 4 × 10^10 hot atoms with a metrologically relevant steady-state squeezing of 3.23±0.24dB, by using both predictive and retrodictive measurement records. We further employ the system to track different types of continuous time-changing magnetic fields, where we demonstrate the use of deep learning models to infer the time varying fields from the optical measurement record, at or below the quantum level. In the end of the talk, I will describe my group’s effort in further reducing quantum fluctuations in atomic sensors, including simultaneous squeezing of the atomic spin and the light, and hybrid squeezing of the internal atomic spin and the collective spin.