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Related papers: Geometry of quantum systems: density states and en…

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In this paper we study the para-hyperK\"ahler geometry of the deformation space of MGHC anti-de Sitter structures on $\Sigma\times\mathbb R$, for $\Sigma$ a closed oriented surface. We show that a neutral pseudo-Riemannian metric and three…

Differential Geometry · Mathematics 2025-04-24 Filippo Mazzoli , Andrea Seppi , Andrea Tamburelli

Quantum coherence and distributed correlations among subparties are often considered as separate, although operationally linked to each other, properties of a quantum state. Here, we propose a measure able to quantify the contributions…

Quantum Physics · Physics 2018-12-11 Gian Luca Giorgi , Roberta Zambrini

We explore the conceptual usefulness of Riemannian geometric tools induced by the statistical concept of distinguishability in quantifying the effect of a depolarizing channel on quantum states. Specifically, we compare the geometries of…

Mathematical Physics · Physics 2012-05-01 Carlo Cafaro , Stefano Mancini

In this paper we give a method to associate a graph with an arbitrary density matrix referred to a standard orthonormal basis in the Hilbert space of a finite dimensional quantum system. We study the related issues like classification of…

Quantum Physics · Physics 2007-08-28 Ali Saif M. Hassan , Pramod Joag

The geometric properties of quantum states are crucial for understanding many physical phenomena in quantum mechanics, condensed matter physics, and optics. The central object describing these properties is the quantum geometric tensor,…

Mathematical Physics · Physics 2026-01-21 Marius A. Oancea , Thomas B. Mieling , Giandomenico Palumbo

Quantum entanglement is a defining signature and resource of quantum theory, but its standard definition presupposes a globally fixed decomposition into subsystems. We develop a geometric framework that detects when such a decomposition…

Algebraic Geometry · Mathematics 2026-01-27 Kazuki Ikeda

The study of conditional $q$-entropies in composite quantum systems has recently been the focus of considerable interest, particularly in connection with the problem of separability. The $q$-entropies depend on the density matrix $\rho$…

Quantum Physics · Physics 2009-11-10 J. Batle , A. R. Plastino , M. Casas , A. Plastino

The topology of the embedding of the coadjoint orbits of the unitary group U(H) of an in-finite dimensional complex Hilbert space H, as canonically determined subsets of the B-space T_s of symmetric trace class operators, is investigated.…

Mathematical Physics · Physics 2018-04-26 Pavel Bona

The entanglement in a pure state of N qudits (d-dimensional distinguishable quantum particles) can be characterised by specifying how entangled its subsystems are. A generally mixed subsystem of m qudits is obtained by tracing over the…

Quantum Physics · Physics 2009-11-07 Vivien M Kendon , Karol Zyczkowski , William J Munro

The unitary group acting on the Hilbert space of three quantum bits admits a Lie subgroup, of elements which permute with the symmetric group of permutations. Under the action of such Lie subgroup, the Hilbert space splits into three…

Quantum Physics · Physics 2021-11-16 Francesca Albertini , Domenico D'Alessandro

The complex geometry underlying the Schr\"odinger dynamics of coherent states for non-Hermitian Hamiltonians is investigated. In particular two seemingly contradictory approaches are compared: (i) a complex WKB formalism, for which the…

Mathematical Physics · Physics 2012-07-12 Eva-Maria Graefe , Roman Schubert

We reconsider the geometry of pure and mixed states in a finite quantum system. The rangesof eigenvalues of the density matrices delimit a regular simplex (Hypertetrahedron TN) in any dimension N; the polytope isometry group is the…

Quantum Physics · Physics 2009-11-13 Luis J. Boya , Kuldeep Dixit

Optimal universal entanglement processes are discussed which entangle two quantum systems in an optimal way for all possible initial states. It is demonstrated that the linear character of quantum theory which enforces the peaceful…

Quantum Physics · Physics 2007-05-23 G. Alber

The space of states and operators for a large class of background independent theories of quantum spacetime dynamics is defined. The SU(2) spin networks of quantum general relativity are replaced by labelled compact two-dimensional…

General Relativity and Quantum Cosmology · Physics 2016-08-25 Fotini Markopoulou , Lee Smolin

The properties which give quantum mechanics its unique character - unitarity, complementarity, non-commutativity, uncertainty, nonlocality - derive from the algebraic structure of Hermitian operators acting on the wavefunction in complex…

Quantum Physics · Physics 2022-09-14 Tim Palmer

This paper presents an introduction to geometric representations of quantum states in which each distinct quantum state, pure and mixed, corresponds to a unique point in a Euclidean space. Beginning with a review of some underappreciated…

Quantum Physics · Physics 2026-02-17 Athanasios Kostikas , Yaroslav Valchyshen , Paul Cadden-Zimansky

When a quantum pure state is drawn uniformly at random from a Hilbert space, the state is typically highly entangled. This property of a random state is known as generic entanglement of quantum states and has been long investigated from…

Quantum Physics · Physics 2020-06-23 Yoshifumi Nakata , Mio Murao

Let $G$ be a semisimple Lie group, ${\frak g}$ its Lie algebra. For any symmetric space $M$ over $G$ we construct a new (deformed) multiplication in the space $A$ of smooth functions on $M$. This multiplication is invariant under the action…

High Energy Physics - Theory · Physics 2008-02-03 J. Donin , S. Shnider

Entanglement asymmetry is an observable in quantum systems, constructed using quantum-information methods, suited to detecting symmetry breaking in states -- possibly out of equilibrium -- relative to a subsystem. In this paper we define…

High Energy Physics - Theory · Physics 2026-01-27 Francesco Benini , Pasquale Calabrese , Michele Fossati , Amartya Harsh Singh , Marco Venuti

There are various statements in the physics literature about the stratification of quantum states, for example into orbits of a unitary group, and about generalized differentiable structures on it. Our aim is to clarify and make precise…

Operator Algebras · Mathematics 2021-12-28 Francesco D'Andrea , Davide Franco