We address metrological protocols for the estimation of the intensity and the orientation of a magnetic field, and show that quantum-enhanced precision may be achieved by probing the field with an arbitrary spin at thermal equilibrium. A general expression is derived for the ultimate achievable precision, as given by the quantum Fisher information. The optimal observable is shown to correspond to the spin projection along a temperature-dependent direction, and allows a maximally precise parameter estimation also through ensemble measurements. Finally, we prove the robustness of our scheme against deviations of the measured spin projection from optimality.
Universal Quantum Magnetometry with Spin States at Equilibrium / F. Troiani, M.G.A. Paris. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 120:26(2018 Jun 28).
Universal Quantum Magnetometry with Spin States at Equilibrium
M.G.A. ParisPenultimo
2018
Abstract
We address metrological protocols for the estimation of the intensity and the orientation of a magnetic field, and show that quantum-enhanced precision may be achieved by probing the field with an arbitrary spin at thermal equilibrium. A general expression is derived for the ultimate achievable precision, as given by the quantum Fisher information. The optimal observable is shown to correspond to the spin projection along a temperature-dependent direction, and allows a maximally precise parameter estimation also through ensemble measurements. Finally, we prove the robustness of our scheme against deviations of the measured spin projection from optimality.File | Dimensione | Formato | |
---|---|---|---|
PhysRevLett.120.260503.pdf
accesso aperto
Tipologia:
Publisher's version/PDF
Dimensione
534.6 kB
Formato
Adobe PDF
|
534.6 kB | Adobe PDF | Visualizza/Apri |
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.