Topical Seminar: Multiparameter quantum metrology with an array of entangled BECs

por Dr. Yifan Li (Ecole Normale Superieure, Paris)

jueves 1 oct. 2026 11:00 → 12:00 Europe/Madrid

4-4-4426 - Seminari Física Teòrica (Campus Burjassot)

In this talk, I will present experiments carried out at the
University of Basel, in which we realized multiparameter quantum
metrology with an array of entangled atomic ensembles [2]. By
coherently splitting a spin-squeezed Bose–Einstein condensate, we
first generated strong entanglement between two spatially separated
condensates and used it to demonstrate the
Einstein–Podolsky–Rosen paradox with massive many-particle
systems [3]. We then extended this approach to an array of BECs.
Local spin rotations applied to the individual BEC allow us to
flexibly configure the spin correlations to enhance measurement
precision of multiple parameters jointly. Combined with an optimal
estimation protocol, these correlations provide a significant
precision advantage beyond the standard quantum limit [2]. Our
results demonstrate how entanglement shared among sensors can serve
as a resource for multiparameter estimation and distributed quantum
sensing.

[1] Y. Baamara et al., SciPost Phys. 14, 050 (2023).
[2] Y. Li et al., Science 391, 374 (2026).
[3] P. Colciaghi et al., Phys. Rev. X 13, 021031 (2023).