Critical quantum metrology assisted by real-time feedback control
- URL: http://arxiv.org/abs/2211.07688v1
- Date: Mon, 14 Nov 2022 19:06:14 GMT
- Title: Critical quantum metrology assisted by real-time feedback control
- Authors: Raffaele Salvia, Mohammad Mehboudi, and Mart\'i Perarnau-Llobet
- Abstract summary: We first derive a no-go result stating that any non-adaptive measurement strategy will fail to exploit quantum critical enhancement.
We then consider different adaptive strategies that can overcome this no-go result.
Our results show that adaptive strategies with real-time feedback control can achieve sub-shot noise scaling.
- Score: 0.0
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: 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 non-adaptive measurement 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.
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