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We provide a generalized treatment of uncertainties, von Neumann entropy, and squeezing in entangled bipartite pure state of two-level atoms. We observe that when the bipartite state is entangled, though the von Neumann entropy of the…

Quantum Physics · Physics 2025-06-04 Ram Narayan Deb

We review studies of entanglement entropy in systems with quenched randomness, concentrating on universal behavior at strongly random quantum critical points. The disorder-averaged entanglement entropy provides insight into the quantum…

Disordered Systems and Neural Networks · Physics 2015-05-13 Gil Refael , Joel E. Moore

We propose a simple approach to the calculation of the entanglement entropy of a spherically symmetric quantum system composed of two separate regions. We consider bound states of the system described by a wave function that is scale…

Quantum Physics · Physics 2019-02-12 Maurizio Melis

We investigate quantum dynamical systems defined on a finite dimensional Hilbert space and subjected to an interaction with an environment. The rate of decoherence of initially pure states, measured by the increase of their von Neumann…

Quantum Physics · Physics 2009-11-10 Robert Alicki , Artur Lozinski , Prot Pakonski , Karol Zyczkowski

We generalize the concept of the Wehrl entropy of quantum states which gives a basis-independent measure of their localization in phase space. We discuss the minimal values and the typical values of these R{enyi-Wehrl entropies for pure…

Quantum Physics · Physics 2009-11-07 Sven Gnutzmann , Karol Zyczkowski

Here we deconstruct, and then in a reasoned way reconstruct, the concept of "entropy of a system," paying particular attention to where the randomness may be coming from. We start with the core concept of entropy as a COUNT associated with…

General Physics · Physics 2017-05-10 Tommaso Toffoli

We use large-$N$ diagrammatic techniques to calculate the relative entropy of symmetric random states drawn from the Wishart ensemble. These methods are specifically designed for symmetric sectors, allowing us to determine the relative…

High Energy Physics - Theory · Physics 2024-11-28 Mostafa Ghasemi

The von Neumann entropy and the subentropy of a mixed quantum state are upper and lower bounds, respectively, on the accessible information of any ensemble consistent with the given mixed state. Here we define and investigate a set of…

Quantum Physics · Physics 2007-05-23 Sarah R. Nichols , William K. Wootters

The entropy accumulation theorem states that the smooth min-entropy of an $n$-partite system $A = (A_1, \ldots, A_n)$ is lower-bounded by the sum of the von Neumann entropies of suitably chosen conditional states up to corrections that are…

Quantum Physics · Physics 2019-07-23 Frédéric Dupuis , Omar Fawzi

We consider quantum algebras of observables associated with subregions in theories of Einstein gravity coupled to matter in the $G_N\rightarrow 0$ limit. When the subregion is spatially compact or encompasses an asymptotic boundary, we…

High Energy Physics - Theory · Physics 2024-02-07 Kristan Jensen , Jonathan Sorce , Antony Speranza

Typically, the entropy of an isolated system in equilibrium is calculated by counting the number of accessible microstates, or in more general cases by using the Gibbs formula. In irreversible processes entropy spontaneously increases and…

Statistical Mechanics · Physics 2020-04-16 Taha A Malik , Rafael Lopez-Mobilia

A system composed of identical spins and described by a quantum mechanical pure state is analyzed within the statistical framework presented in Part I of this work. We explicitly derive the typical values of the entropy, of the energy, and…

Quantum Physics · Physics 2010-07-22 Barbara Fresch , Giorgio J. Moro

The 1D Mueller dipole model, its high energy limit, and its generalization were investigated. To address the ambiguity stemming from different definitions of the pseudorapidity ranges in experimental measurements, we propose the entropy as…

High Energy Physics - Phenomenology · Physics 2026-04-21 Krzysztof Kutak , Sándor Lökös

It is shown that the volume entropy of a Hilbert geometry associated to an $n$-dimensional convex body of class $C^{1,1}$ equals $n-1$. To achieve this result, a new projective invariant of convex bodies, similar to the centro-affine area,…

Differential Geometry · Mathematics 2010-05-21 Gautier Berck , Andreas Bernig , Constantin Vernicos

The large time, small mass, asymptotic behavior of the average mass distribution $\pb$ is studied in a $d$-dimensional system of diffusing aggregating particles for $1\leq d \leq 2$. By means of both a renormalization group computation as…

Statistical Mechanics · Physics 2009-11-07 Supriya Krishnamurthy , R. Rajesh , Oleg Zaboronski

Most states in the Hilbert space are maximally entangled. This fact has proven useful to investigate - among other things - the foundations of statistical mechanics. Unfortunately, most states in the Hilbert space of a quantum many body…

Quantum Physics · Physics 2015-05-30 Alioscia Hamma , Siddhartha Santra , Paolo Zanardi

We consider scattering processes where a quantum system is comprised of an inner subsystem and of a boundary, and is subject to Haar-averaged random unitaries acting on the boundary-environment Hilbert space only. We show that, regardless…

Quantum Physics · Physics 2023-08-30 Michele Avalle , Alessio Serafini

We show how to determine the maximum and minimum possible values of one measure of entropy for a given value of another measure of entropy. These maximum and minimum values are obtained for two standard forms of probability distribution (or…

Quantum Physics · Physics 2007-05-23 Dominic W. Berry , Barry C. Sanders

We develop a quantum relative entropy method for the mean-field limit of quantum many-body systems. For closed systems governed by the von Neumann equation, we prove a quantitative stability estimate between the $N$-body density matrix and…

Mathematical Physics · Physics 2026-05-12 Gaoyue Guo , Hao Liang , Zhenfu Wang

We consider ensembles of pure Gaussian states parametrized by single-mode marginals and (optionally) specific mode-mode correlations. Such ensembles provide a model for the final states when isolated quantum systems thermalize, as they can…

Quantum Physics · Physics 2026-03-24 Erik Aurell , Lucas Hackl , Mario Kieburg