Semi-classical geometric tensor in multiparameter quantum information

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Imai, Satoya, Yang, Jing, Pezzè, Luca
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915941017714688
author Imai, Satoya
Yang, Jing
Pezzè, Luca
author_facet Imai, Satoya
Yang, Jing
Pezzè, Luca
contents The discrepancy between quantum distinguishability in Hilbert space and classical distinguishability in probability space is expressed by the gap between the quantum and classical Fisher information matrices (QFIM and CFIM, respectively). This intrinsic quantum obstruction is generally not saturable and plays a central role in both fundamental insights and practical applications in modern quantum physics. Here, we develop a geometrical framework for this gap by introducing the notion of semi-classical geometric tensor (SCGT). We relate this quantity to the quantum geometric tensor (QGT), whose real part equals the QFIM. We prove the matrix inequality between QGT and SCGT, which sharpens the standard inequality between QFIM and CFIM and provides novel multiparameter information bounds: the real part of the SCGT reproduces the CFIM plus an additional nonnegative contribution capturing quantum obstruction. This further motivates a natural extension of the Berry phase to the semi-classical setting.
format Preprint
id arxiv_https___arxiv_org_abs_2504_06812
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Semi-classical geometric tensor in multiparameter quantum information
Imai, Satoya
Yang, Jing
Pezzè, Luca
Quantum Physics
Mesoscale and Nanoscale Physics
Materials Science
The discrepancy between quantum distinguishability in Hilbert space and classical distinguishability in probability space is expressed by the gap between the quantum and classical Fisher information matrices (QFIM and CFIM, respectively). This intrinsic quantum obstruction is generally not saturable and plays a central role in both fundamental insights and practical applications in modern quantum physics. Here, we develop a geometrical framework for this gap by introducing the notion of semi-classical geometric tensor (SCGT). We relate this quantity to the quantum geometric tensor (QGT), whose real part equals the QFIM. We prove the matrix inequality between QGT and SCGT, which sharpens the standard inequality between QFIM and CFIM and provides novel multiparameter information bounds: the real part of the SCGT reproduces the CFIM plus an additional nonnegative contribution capturing quantum obstruction. This further motivates a natural extension of the Berry phase to the semi-classical setting.
title Semi-classical geometric tensor in multiparameter quantum information
topic Quantum Physics
Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2504.06812