We address quantum critical systems as a resource in quantum estimation and derive the ultimate quantum limits to the precision of any estimator of the coupling parameters. In particular, if L denotes the size of a system and lambda is the relevant coupling parameters driving a quantum phase transition, we show that a precision improvement of order 1/L may be achieved in the estimation of lambda at the critical point compared to the noncritical case. We show that analog results hold for temperature estimation in classical phase transitions. Results are illustrated by means of a specific example involving a fermion tight-binding model with pair creation (BCS model).

Quantum criticality as a resource for quantum estimation / P. Zanardi, M. Paris, L. Campos Venuti. - In: PHYSICAL REVIEW A. - ISSN 1050-2947. - 78:4(2008), pp. 042105.042105.1-042105.042105.7.

Quantum criticality as a resource for quantum estimation

M. Paris
Secondo
;
2008

Abstract

We address quantum critical systems as a resource in quantum estimation and derive the ultimate quantum limits to the precision of any estimator of the coupling parameters. In particular, if L denotes the size of a system and lambda is the relevant coupling parameters driving a quantum phase transition, we show that a precision improvement of order 1/L may be achieved in the estimation of lambda at the critical point compared to the noncritical case. We show that analog results hold for temperature estimation in classical phase transitions. Results are illustrated by means of a specific example involving a fermion tight-binding model with pair creation (BCS model).
statistical distance ; fisher information ; mechanics ; geometry ; states ; phase
Settore FIS/03 - Fisica della Materia
2008
Article (author)
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/52389
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 188
  • ???jsp.display-item.citation.isi??? 177
social impact