Berlin 2024 – scientific programme
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QI: Fachverband Quanteninformation
QI 32: Quantum Sensing and Metrology
QI 32.2: Talk
Friday, March 22, 2024, 10:00–10:15, HFT-FT 131
Squeezed Superradiance Enables Robust Entanglement-Enhanced Metrology Even with Highly Imperfect Readout — •Martin Koppenhöfer1,3, Peter Groszkowski1,2, and Aashish A. Clerk1 — 1Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA — 2National Center for Computational Sciences, Oak Ridge National Laboratory, Tennessee 37831, USA — 3Fraunhofer-Institut für Angewandte Festkörperphysik IAF, Tullastraße 72, 79108 Freiburg, Deutschland
Quantum metrology protocols using entangled states of large spin ensembles attempt to achieve measurement sensitivities surpassing the standard quantum limit (SQL), but in many cases they are severely limited by even small amounts of technical noise associated with imperfect sensor readout. Amplification strategies based on time-reversed coherent spin-squeezing dynamics have been devised to mitigate this issue, but are unfortunately very sensitive to dissipation, requiring a large single-spin cooperativity to be effective. Here, we propose a new dissipative protocol that combines amplification and squeezed fluctuations. It enables the use of entangled spin states for sensing well beyond the SQL even in the presence of significant readout noise. Further, it has a strong resilience against undesired single-spin dissipation, requiring only a large collective cooperativity to be effective.
Keywords: Spin amplification; Entanglement-assisted quantum sensing; Strong readout noise; Spin squeezing; Engineered dissipation