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In quantum theory, the inescapable interaction between a system and its surroundings would lead to a loss of coherence and leakage of information into the environment. An effective approach to retain the quantum characteristics of the…

Quantum Physics · Physics 2025-08-29 Guohui Dong , Yao Yao

Issues related to quantum entanglement in systems of indistinguishable particles, as discussed in the information theoretic approach, are extended to anyonic statistics. Local and non-local measurements discussed in this framework are…

Quantum Physics · Physics 2021-10-28 Ramadas N , V V Sreedhar

We propose a method to construct universal order parameters for quantum phase transitions in many-body lattice systems. The method exploits the $H$-orthogonality of a few near-degenerate lowest states of the Hamiltonian describing a given…

Statistical Mechanics · Physics 2015-01-09 Qian-Qian Shi , Huan-Qiang Zhou , Murray T. Batchelor

We study the adiabatic limit in the density matrix approach for a quantum system coupled to a weakly dissipative medium. The energy spectrum of the quantum model is supposed to be non-degenerate. In the absence of dissipation, the geometric…

Quantum Physics · Physics 2015-06-26 A. C. Aguiar Pinto , K. M. Fonseca Romero , M. T. Thomaz

A useful concept for finding numerically the dominant correlations of a given ground state in an interacting quantum lattice system in an unbiased way is the correlation density matrix. For two disjoint, separated clusters, it is defined to…

Strongly Correlated Electrons · Physics 2015-05-14 W. Münder , A. Weichselbaum , A. Holzner , J. von Delft , C. L. Henley

We report the creation of a wide range of quantum states with controllable degrees of entanglement and entropy using an optical two-qubit source based on spontaneous parametric downconversion. The states are characterised using measures of…

Quantum Physics · Physics 2009-11-07 A. G. White , D. F. V. James , W. J. Munro , P. G. Kwiat

Presented here is a matrix inversion method utilizing quantum searching algorithm. In this method, huge Hilbert space as a whole spanned by myriad of eigen states is searched and evaluated efficiently by sequential reduction in dimension…

Quantum Physics · Physics 2007-05-23 Atsushi Miyauchi

Quantum information is a rapidly advancing area of interdisciplinary research. It may lead to real-world applications for communication and computation unavailable without the exploitation of quantum properties such as nonorthogonality or…

Quantum Physics · Physics 2009-11-10 Samuel L. Braunstein , Peter van Loock

We present the exact solution of the one-dimensional extended Hubbard model in the atomic limit within the Green's function and equation of motion formalism. We provide a comprehensive and systematic analysis of the model by considering all…

Strongly Correlated Electrons · Physics 2008-07-25 F. Mancini , F. P. Mancini

An expansion method for perturbation of the zero temperature grand canonical density matrix is introduced. The method achieves quadratically convergent recursions that yield the response of the zero temperature density matrix upon variation…

Materials Science · Physics 2009-11-10 Anders M. N. Niklasson , Matt Challacombe

We study quantum information masking of arbitrary dimensional states. Given a set of fixed reducing pure states, we study the linear combinations of them, such that they all have the same marginal states with the given ones. We define the…

Quantum Physics · Physics 2021-10-01 Bao-Zhi Sun , Shao-Ming Fei , Xianqing Li-Jost

Although effective for two dimensional (2D) systems, some approximations may fail in describing the properties of one-dimensional (1D) models, which belong to a different universality class. In this paper, we analyze the adequacy of the…

Strongly Correlated Electrons · Physics 2007-05-23 Adolfo Avella , Ferdinando Mancini , Maria del Mar Sanchez-Lopez

We are interested in assessing the order of a finite-state Hidden Markov Model (HMM) with the only two assumptions that the transition matrix of the latent Markov chain has full rank and that the density functions of the emission…

Statistics Theory · Mathematics 2023-11-29 Marie Du Roy de Chaumaray , Salima El Kolei , Marie-Pierre Etienne , Matthieu Marbac

We study measures of quantum information when the space spanned by the set of accessible observables is not closed under products, i.e., we consider systems where an observer may be able to measure the expectation values of two operators,…

High Energy Physics - Theory · Physics 2018-08-15 Sudip Ghosh , Suvrat Raju

We develop information-theoretic measures of spatial structure and pattern in more than one dimension. As is well known, the entropy density of a two-dimensional configuration can be efficiently and accurately estimated via a converging…

Statistical Mechanics · Physics 2009-11-07 David P. Feldman , James P. Crutchfield

Density matrix embedding theory (DMET) provides a framework to describe ground-state expectation values in strongly correlated systems, but its extension to dynamical quantities is still an open problem. We show one route to obtaining…

Strongly Correlated Electrons · Physics 2025-11-13 Shuoxue Li , Chenghan Li , Huanchen Zhai , Garnet Kin-Lic Chan

In traditional QCD sum rules, the simple hadron spectral density model of ``delta-function-type ground state + theta-function-type continuous spectrum" determines that there is no perfect parameter selection. In recent years, inverse…

High Energy Physics - Phenomenology · Physics 2024-07-16 Zhen-Xing Zhao , Yi-Peng Xing , Run-Hui Li

This review focuses on the field of quantum entanglement applied to condensed matter physics systems with strong correlations, a domain which has rapidly grown over the last decade. By tracing out part of the degrees of freedom of…

Strongly Correlated Electrons · Physics 2016-08-11 Nicolas Laflorencie

Motivated by recent quantum gas microscope experiments for fermions in optical lattices, we present proof of principle calculations showing that it is possible to obtain the complete information about the quantum state on a small subsystem…

Strongly Correlated Electrons · Physics 2019-09-16 Stephan Humeniuk

The resources needed to conventionally characterize a quantum system are overwhelmingly large for high- dimensional systems. This obstacle may be overcome by abandoning traditional cornerstones of quantum measurement, such as general…

Quantum Physics · Physics 2016-05-17 Gregory A. Howland , Samuel H. Knarr , James Schneeloch , Daniel J. Lum , John C. Howell