Quantum criticality as a resource for quantum estimation

By Paolo Zanardi, Matteo G. A. Paris, L. Venuti. 2007

261 citations recorded by the source corpus.

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 $\ensuremath{\lambda}$ 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 $\ensuremath{\lambda}$ 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).

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/de35e08a64170e9c3954454b7c32a920192a6677

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In Artificial Intelligence

In Atomic and Molecular Physics, and Optics

Citations in the corpus

Quantum-enhanced measurements without entanglement (2017, methodology): “…modes {cj , c†j}j , periodic boundary conditions, and J > 0: 39 Aj,l = (J − µ) δj,l − J θ(1− |j − l|), Bj,l = Jγ sign(l − j) θ(1− |j − l|), (102) Such Hamiltonian (Zanardi et al., 2008) is also equal to Hquasi-spin = bL2 c∑ n=1 ( − nσzn + ∆nσyn ) , (103) with n = −J cos ( 2πn L ) − µ2 , ∆n =…”
Geometry of quantum phase transitions (2019, background): “The universal scaling properties of quantities related to the fidelity approach, such as the fidelity susceptibility [195, 228, 229], the quantum geometric tensor [42, 160] and the Fisher information matrix [230], have been investigated and exploited in numerous scenarios.”
Quantum spin squeezing (2010, unknown): “Here, we discuss spin squeezing and QFI in quantummetrology [171,249–252].”