English
Related papers

Related papers: Quantum Circuits, Feature Maps, and Expanded Pseud…

200 papers

Quantum entropy is an important measure for describing the uncertainty of a quantum state, more uncertainty in subsystems implies stronger quantum entanglement between subsystems. Our goal in this work is to quantify bipartite entanglement…

Quantum Physics · Physics 2022-04-18 Xue Yang , Yan-Han Yang , Li-Ming Zhao , Ming-Xing Luo

We present a technique for enhancing the estimation of quantum state properties by incorporating approximate prior knowledge about the quantum state of interest. This method involves performing randomized measurements on a quantum processor…

Non-linear properties of quantum states, such as entropy or entanglement, quantify important physical resources and are frequently used in quantum information science. They are usually calculated from a full description of a quantum state,…

Quantum algorithms for computing classical nonlinear maps are widely known for toy problems but might not suit potential applications to realistic physics simulations. Here, we propose how to compute a general differentiable invertible…

Quantum Physics · Physics 2021-05-18 I. Y. Dodin , E. A. Startsev

Analytically continuing the von Neumann entropy from R\'enyi entropies is a challenging task in quantum field theory. While the $n$-th R\'enyi entropy can be computed using the replica method in the path integral representation of quantum…

High Energy Physics - Theory · Physics 2023-05-03 Chih-Hung Wu , Ching-Che Yen

Quantum information theory, particularly its entropic formulations, has made remarkable strides in characterizing quantum systems and tasks. However, a critical dimension remains underexplored: computational efficiency. While classical…

Quantum Physics · Physics 2026-05-05 Noam Avidan , Thomas A. Hahn , Joseph M. Renes , Rotem Arnon

For a closed-loop control system with a digital channel between the sensor and the controller, the notion of invariance entropy quantifies the smallest average rate of information above which a given compact subset of the state space can be…

Optimization and Control · Mathematics 2021-11-19 Mahendra Singh Tomar , Christoph Kawan , Majid Zamani

Entanglement is a defining property of quantum systems. For a subsystem of a larger quantum system, one can formally define an operator known as the modular Hamiltonian, which is closely linked to the entanglement properties of that…

Quantum Physics · Physics 2025-08-26 Ian T. Lim , Isaac H. Kim

We study fidelity and fidelity susceptibility by addition of entanglement of entropy in the one-dimensional quantum compass model in a transverse magnetic field numerically. The whole four recognized gapped regions in the ground state phase…

Strongly Correlated Electrons · Physics 2014-06-13 Mostafa Motamedifar , Somayyeh Nemati , Saeed Mahdavifar , Saber Farjami Shayesteh

Following arXiv:2210.12963 [hep-th], we investigate aspects of the time evolution operator regarded as a density operator and associated entanglement-like structures in various quantum systems. These involve timelike separations and…

High Energy Physics - Theory · Physics 2024-04-29 K. Narayan , Hitesh K. Saini

Quantum state tomography is an integral part of quantum computation and offers the starting point for the validation of various quantum devices. One of the central tasks in the field of state tomography is to reconstruct with high fidelity,…

Quantum Physics · Physics 2022-12-21 Rishabh Gupta , Manas Sajjan , Raphael D. Levine , Sabre Kais

In the study of quantum limits to parameter estimation, the high dimensionality of the density operator and that of the unknown parameters have long been two of the most difficult challenges. Here we propose a theory of quantum…

Quantum Physics · Physics 2020-08-05 Mankei Tsang , Francesco Albarelli , Animesh Datta

Understanding the limitations imposed by noise on current and next-generation quantum devices is a crucial step towards demonstrating practical quantum advantage. In this work, we investigate the accumulation of entropy density as a…

Quantum Physics · Physics 2026-01-16 Marine Demarty , James Mills , Kenza Hammam , Raul Garcia-Patron

The density matrix is a positive semidefinite operator of trace 1 characterizing the state of a quantum system. We consider the inverse problem to reconstruct such density matrices from indirect measurements, also known as quantum state…

Numerical Analysis · Mathematics 2026-03-06 Florian Oberender , Thorsten Hohage

Pseudo-random operators consist of sets of operators that exhibit many of the important statistical features of uniformly distributed random operators. Such pseudo-random sets of operators are most useful whey they may be parameterized and…

Quantum Physics · Physics 2009-11-10 Joseph Emerson

The von Neumann entropy plays a vital role in quantum information theory. The von Neumann entropy determines, e.g., the capacities of quantum channels. Also, entropies of composite quantum systems are important for future quantum networks,…

Quantum Physics · Physics 2018-10-31 Christian Majenz

We extend algorithmic information theory to quantum mechanics, taking a universal semicomputable density matrix (``universal probability'') as a starting point, and define complexity (an operator) as its negative logarithm. A number of…

Quantum Physics · Physics 2009-11-06 Peter Gacs

Entropy plays a crucial role in both physics and information science, encompassing classical and quantum domains. In this work, we present the Quantum Neural Entropy Estimator (QNEE), a novel approach that combines classical neural network…

Quantum Physics · Physics 2023-12-19 Sangyun Lee , Hyukjoon Kwon , Jae Sung Lee

This paper introduces a numerical framework for establishing lower bounds on the conditional von-Neumann entropy in device-independent quantum cryptography and randomness extraction scenarios. Leveraging a hierarchy of semidefinite programs…

Quantum Physics · Physics 2025-08-22 Gereon Koßmann , René Schwonnek

TThe organization and structure of bipartite mixed-state quantum entanglement (QE) are more complex and less well understood compared to bipartite pure-state QE. Bipartite mixed-state QEs and their measures play a crucial role in both…

Quantum Physics · Physics 2025-10-14 Jing-Min Zhu