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We introduce the category $\mathsf{NCP}$, whose objects are pairs of W$^\ast$-algebras and normal states and whose morphisms are state-preserving unital completely positive (CPU) maps, as a common stage for classical and quantum information…

Mathematical Physics · Physics 2025-09-15 Florio M. Ciaglia , Fabio Di Cosmo , Laura González-Bravo

A quantum system can be entirely described by the K\"ahler structure of the projective space P(H) associated to the Hilbert space H of possible states; this is the so-called geometrical formulation of quantum mechanics. In this paper, we…

Differential Geometry · Mathematics 2012-02-07 Mathieu Molitor

We explore the relation between quantum geometry in non-Hermitian systems and physically measurable phenomena. We highlight various situations in which the behavior of a non-Hermitian system is best understood in terms of quantum geometry,…

Quantum Physics · Physics 2026-03-16 Anton Montag , Tomoki Ozawa

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).…

Quantum Physics · Physics 2026-04-20 Satoya Imai , Jing Yang , Luca Pezzè

The conventional quantum geometric tensor (QGT) is Hermitian, with a real symmetric quantum metric and an imaginary antisymmetric Berry curvature. We show that the Zeeman QGT is generically non-Hermitian and admits a natural decomposition…

Quantum Physics · Physics 2026-04-29 Rongjie Cui , Longjun Xiang , Fuming Xu , Jian Wang

We apply concepts of random differential geometry connected to the random matrix ensembles of the random linear operators acting on finite dimensional Hilbert spaces. The values taken by random linear operators belong to the Liouville…

Statistical Mechanics · Physics 2007-05-23 Maciej M. Duras

The quantum geometric tensor, composed of the quantum metric tensor and Berry curvature, fully encodes the parameter space geometry of a physical system. We first provide a formulation of the quantum geometrical tensor in the path integral…

Quantum Physics · Physics 2023-08-16 Sergio B. Juárez , Diego Gonzalez , Daniel Gutiérrez-Ruiz , J. David Vergara

We introduce analogues of the Fubini-Study metrics and the corresponding Levi-Civita connections on quantum projective spaces. We define the quantum metrics as two-tensors, symmetric in the appropriate sense, in terms of the differential…

Quantum Algebra · Mathematics 2023-09-22 Marco Matassa

We develop a comprehensive axiomatic framework for quantum-inspired distance metrics on projective Hilbert spaces, providing a unified foundation that organizes and generalizes existing measures in quantum information theory. Starting from…

Quantum Physics · Physics 2026-03-03 Maryam Bagherian

We consider the geometry of quantum states associated with different classes of random matrix Hamiltonians, in particular ensembles that show integrability to chaotic transition in terms of the nearest neighbour energy level spacing…

Quantum Physics · Physics 2025-09-03 Ankit Gill , Keun-Young Kim , Kunal Pal , Kuntal Pal

As a fundamental concept in condensed matter physics, quantum geometry within the Riemannian metric elucidates various exotic phenomena, including the Hall effects driven by Berry curvature and quantum metric. In this work, we propose novel…

Mesoscale and Nanoscale Physics · Physics 2024-10-01 Miaomiao Wei , Longjun Xiang , Fuming Xu , Baigeng Wang , Jian Wang

We derive an explicit expressions for geometric description of state manifold obtained from evolution governed by a three parameter family of Hamiltonians covering most cases related to real interacting two-qubit systems. We discuss types…

Quantum Physics · Physics 2019-06-12 Andrzej M. Frydryszak , Maria Gieysztor , Andrij Kuzmak

We show how fermionic statistics can be naturally incorporated in tensor networks on arbitrary graphs through the use of graded Hilbert spaces. This formalism allows to use tensor network methods for fermionic lattice systems in a local…

Quantifying measurement precision in quantum systems is vital for advancing quantum technologies such as sensing, communication, and computation. The quantum Fisher information (QFI) sets the ultimate precision bound in Hermitian systems;…

Quantum Physics · Physics 2026-03-12 Javid Naikoo , Ravindra W. Chhajlany , Jan Kołodyński , Adam Miranowicz

This work introduces a geometrical object that generalizes the quantum geometric tensor; we call it $N$-bein. Analogous to the vielbein (orthonormal frame) used in the Cartan formalism, the $N$-bein behaves like a ``square root'' of the…

Quantum Physics · Physics 2024-08-16 Jorge Romero , Carlos A. Velasquez , J David Vergara

In this paper we consider the space of those probability distributions which maximize the $q$-R\'enyi entropy. These distributions have the same parameter space for every $q$, and in the $q=1$ case these are the normal distributions. Some…

Probability · Mathematics 2017-08-24 Attila Andai

The eigenvalues of a parameter-dependent Hamiltonian matrix form a band structure in parameter space. In such $N$-band systems, the quantum geometric tensor (QGT), consisting of the Berry curvature and quantum metric tensors, is usually…

Other Condensed Matter · Physics 2021-08-18 Ansgar Graf , Frédéric Piéchon

While the exact separability probability of 8/33 for two-qubit states under the Hilbert-Schmidt measure has been reported by Huong and Khoi [\href{https://doi.org/10.1088/1751-8121/ad8493}{J.Phys.A:Math.Theor.{\bf57}, 445304(2024)}],…

Quantum Physics · Physics 2026-03-13 Lin Zhang , Xiaohan Jiang , Bing Xie

The quantum metric, a key component of quantum geometry, plays a central role in a wide range of physical phenomena and has been extensively studied in periodic crystals and moir\'{e} materials. Here, we systematically investigate quantum…

Mesoscale and Nanoscale Physics · Physics 2025-07-08 Jundi Wang , Yuxiao Chen , Huaqing Huang

In this paper we study the structure of the Hilbert space for the recent noncommutative geometry models of gauge theories. We point out the presence of unphysical degrees of freedom similar to the ones appearing in lattice gauge theories…

High Energy Physics - Theory · Physics 2010-11-19 F. Lizzi , G. Mangano , G. Miele , G. Sparano