Freiburg 2024 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 36: Quantum Metrology and Interference
Q 36.1: Talk
Wednesday, March 13, 2024, 14:30–14:45, HS 3219
Quantum parameter estimation with many-body fermionic systems and application to the quantum Hall effect — Olivier Giraud1, Mark-Oliver Goerbig2, and •Daniel Braun3 — 1Université Paris-Saclay, CNRS, LPTMS, 91405 Orsay, France — 2Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France. — 3Institut für theoretische Physik, Universität Tübingen, 72076 Tübingen, Germany
Quantum metrology with electronic sensors requires the description of the system with a fermionic quantum field theory. To this end, we calculate the quantum Fisher information for a generic many-body fermionic system in a pure state depending on a parameter. The parameter can be imprinted in the basis states, the state coefficients, or in both. We apply our findings to the quantum Hall effect and evaluate the quantum Fisher information associated with the optimal measurement of the magnetic field for a system in the ground state. Remarkably, the occupation of electron states with high momentum enforced by the Pauli principle leads to a super-Heisenberg scaling of the sensitivity with a power law that depends on the geometry of the sensor.
Keywords: quantum metrology; quantum Hall effect; fermionic field theory; super-Heisenberg scaling