Contributor info: Prof. Bernardo Spagnolo

Giovanni Di Fresco, Bernardo Spagnolo, Davide Valenti, Angelo Carollo

SciPost Phys. 13, 077 (2022) · published 3 October 2022 | Toggle abstract · pdf

Single parameter estimation is known to benefit from extreme sensitivity to parameter changes in quantum critical systems. However, the simultaneous estimation of multiple parameters is generally limited due to the incompatibility arising from the quantum nature of the underlying system. A key question is whether quantum criticality may also play a positive role in reducing the incompatibility in the simultaneous estimation of multiple parameters. We argue that this is generally the case and verify this prediction in paradigmatic quantum many-body systems close to first and second order phase tran- sitions. The antiferromagnetic and ferromagnetic 1-D Ising chain with both transverse and longitudinal fields are analysed across different regimes and close to criticality.