Quantum Optics Seminar: Philipp Treutlein

Multiparameter quantum metrology with an array of entangled atomic sensors

Philipp Treutlein

Department of Physics, University of Basel, Switzerland

 In quantum metrology, entangled states of many-particle systems are investigated to enhance measurement precision of the most precise clocks and field sensors. While single-parameter quantum metrology is well established, many metrological tasks require joint multiparameter estimation, which poses new conceptual challenges that have so far only been explored theoretically. I will report experiments where we demonstrate multiparameter quantum metrology with an array of entangled atomic ensembles [1]. By splitting a spin-squeezed Bose-Einstein condensate, we create an atomic sensor array featuring inter-sensor entanglement of the Einstein-Podolsky-Rosen type [2]. Local spin rotations applied to the individual sensors allow us to flexibly configure the entanglement to enhance measurement precision of multiple parameters jointly [3]. Using an optimal estimation protocol, we achieve significant gains over the standard quantum limit in key multiparameter estimation tasks of relevance for field sensor arrays and imaging devices.