English
Related papers

Related papers: Quantum operator entropies under unitary evolution

200 papers

We propose a generalization of the quantum entropy introduced by Wigner and von Neumann in 1929 [Zeitschrift f\"ur Physik 57, 30 (1929)]. Our generalization is applicable to both quantum pure states and mixed states. When the dimension $N$…

Quantum Physics · Physics 2019-05-22 Zhigang Hu , Zhenduo Wang , Biao Wu

The entropy of a quantum operation, defined as the von Neumann entropy of the corresponding Choi-Jamio{\l}kowski state, characterizes the coupling of the principal system with the environment. For any quantum channel $\Phi$ acting on a…

Quantum Physics · Physics 2020-06-02 Jakub Czartowski , Daniel Braun , Karol Życzkowski

In this paper we analyze the entropy and entropy production of a non-isolated quantum system described within the quantum Brownian motion framework. This is a very general and paradigmatic framework for describing non-isolated quantum…

Statistical Mechanics · Physics 2020-09-09 G. A. Weiderpass , A. O. Caldeira

We define a quantum entropy conditioned on post-selection which has the von Neumann entropy of pure states as a special case. This conditional entropy can take negative values which is consistent with part of a quantum system containing…

Quantum Physics · Physics 2014-09-05 Sina Salek , Roman Schubert , Karoline Wiesner

We introduce a framework to study discrete-variable (DV) quantum systems based on qudits. It relies on notions of a mean state (MS), a minimal stabilizer-projection state (MSPS), and a new convolution. Some interesting consequences are: The…

Quantum Physics · Physics 2023-06-21 Kaifeng Bu , Weichen Gu , Arthur Jaffe

The classical thermostatics of equilibrium processes is shown to possess a quantum-mechanical dual theory with a finite-dimensional Hilbert space of quantum states. Specifically, the kernel of a certain Hamiltonian operator becomes the…

Mathematical Physics · Physics 2017-04-05 D. Cabrera , P. Fernandez de Cordoba , J. M. Isidro , J. Vazquez Molina

We present a partition of quantum observables in an open quantum system which is inherited from the division of the underlying Hilbert space or configuration space. It is shown that this partition leads to the definition of an inhomogeneous…

Quantum Physics · Physics 2024-08-20 Caleb M. Webb , Charles A. Stafford

In the above mentioned paper by J. Dunkel and S. A. Trigger [Phys. Rev. {\bf A 71}, 052102, (2005)] a hypothesis has been pursued that the loss of information associated with the quantum evolution of pure states, quantified in terms of an…

Quantum Physics · Physics 2009-11-11 Piotr Garbaczewski

We give a simple proof of the uncertainty principle with quantum side information, as in [Berta et al. Nature Physics 6, 659 (2010)], invoking the monotonicity of the relative entropy. Our proof shows that the entropic uncertainty principle…

Quantum Physics · Physics 2011-12-08 Patrick J. Coles , Li Yu , Michael Zwolak

The entanglement production in bipartite quantum systems is studied for initially unentangled product eigenstates of the subsystems, which are assumed to be quantum chaotic. Based on a perturbative computation of the Schmidt eigenvalues of…

The Second Law of Thermodynamics states that the entropy of a closed system is non-decreasing. Discussing the Second Law in the quantum world poses new challenges and provides new opportunities, involving fundamental…

Quantum Physics · Physics 2016-12-01 A. V. Lebedev , D. Oehri , G. B. Lesovik , G. Blatter

We give an exact formula for the rate of change of the von Neumann entropy for the conditional state of a quantum system undergoing continuous measurement. Here we employ Paycha's Formula \cite{Paycha} which gives the noncommutative Taylor…

Quantum Physics · Physics 2024-07-30 John E. Gough , Nina H. Amini

In this paper, we investigate the time evolution of entanglement entropy and mutual information for the spatially-infinite systems where we act with a primary operator on the vacuum state and then time-evolve it with the sequence of the…

High Energy Physics - Theory · Physics 2025-12-23 Weibo Mao , Akihiro Miyata , Masahiro Nozaki , Farzad Omidi

Entropy is one of the central quantities in thermodynamics, whose flow between two systems determines the statistics of energy transfers. In quantum systems entropy is non-linear in density matrix whose time evolution is cumbersome. Using…

Mesoscale and Nanoscale Physics · Physics 2019-12-06 Mohammad H. Ansari

Entropic force has been drawing the attention of theoretical physicists following E. Verlinde's work in 2011 to derive Newton's second law and Einstein's field equations of general relativity. In this paper, we extend the idea of entropic…

Quantum Physics · Physics 2024-12-03 Jayarshi Bhattacharya , Gautam Gangopadhyay , Sunandan Gangopadhyay

The entanglement between the position and coin state of a $N$-dimensional quantum walker is shown to lead to a thermodynamic theory. The entropy, in this thermodynamics, is associated to the reduced density operator for the evolution of…

Quantum Physics · Physics 2015-06-22 Alejandro Romanelli , Raul Donangelo , Renato Portugal , Franklin L. Marquezino

We study the time evolution of the reduced Wigner function for a class of quantum Brownian motion models. We derive two generalized uncertainty relations. The first consists of a sharp lower bound on the uncertainty function, $U = (\Delta…

General Relativity and Quantum Cosmology · Physics 2011-08-11 C. Anastopoulos , J. J. Halliwell

Motivated by the notion that the mathematics of gravity can be reproduced from a statistical requirement of maximal entropy, we study the consequence of introducing an entropic source term in the Einstein-Hilbert action. For a spatially…

General Relativity and Quantum Cosmology · Physics 2024-03-20 Soumya Chakrabarti

We propose that the constants of Nature we observe (which appear as parameters in the classical action) are quantum observables in a kinematical Hilbert space. When all of these observables commute, our proposal differs little from the…

General Relativity and Quantum Cosmology · Physics 2019-01-09 John D. Barrow , Joao Magueijo

In the setup of isolated quantum systems, it is proved that the thermodynamic entropy and the diagonal entropy must increase extensively in any nontrivial quantum quench. The extensive increase of the thermodynamic entropy is shown for any…

Statistical Mechanics · Physics 2016-10-26 Takashi Mori
‹ Prev 1 8 9 10 Next ›