Critical Quantum Metrology Assisted by Real-Time Feedback Control.
Phys Rev Lett
; 130(24): 240803, 2023 Jun 16.
Article
en En
| MEDLINE
| ID: mdl-37390423
We investigate critical quantum metrology, that is, the estimation of parameters in many-body systems close to a quantum critical point, through the lens of Bayesian inference theory. We first derive a no-go result stating that any nonadaptive strategy will fail to exploit quantum critical enhancement (i.e., precision beyond the shot-noise limit) for a sufficiently large number of particles N whenever our prior knowledge is limited. We then consider different adaptive strategies that can overcome this no-go result and illustrate their performance in the estimation of (i) a magnetic field using a probe of 1D spin Ising chain and (ii) the coupling strength in a Bose-Hubbard square lattice. Our results show that adaptive strategies with real-time feedback control can achieve sub-shot-noise scaling even with few measurements and substantial prior uncertainty.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Campos Magnéticos
Idioma:
En
Revista:
Phys Rev Lett
Año:
2023
Tipo del documento:
Article
País de afiliación:
Italia
Pais de publicación:
Estados Unidos