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Studying the physics of quantum correlations has gained new interest after it has become possible to measure entanglement entropies of few body systems in experiments with ultracold atomic gases. Apart from investigating trapped atom…

Quantum Physics · Physics 2020-09-22 Arkadiusz Kuroś , Anna Okopińska

Consider the question: what statistical ensemble corresponds to minimal prior knowledge about a quantum system ? For the case where the system is in fact known to be in a pure state there is an obvious answer, corresponding to the unique…

Quantum Physics · Physics 2009-10-31 Michael J. W. Hall

In a robotic swarm, parameters such as position and proximity to the target can be described in terms of probability amplitudes. This idea led to recent studies on a quantum approach to the definition of the swarm, including a block-matrix…

Robotics · Computer Science 2026-03-17 Maria Mannone , Mahathi Anand , Peppino Fazio , Abdalla Swikir

Entanglement is the fundamental difference between classical and quantum systems and has become one of the guiding principles in the exploration of high- and low-energy physics. The calculation of entanglement entropies in interacting…

Quantum Physics · Physics 2022-08-17 Patrick Emonts , Ivan Kukuljan

We propose a method to probe the local density of states (LDOS) of atomic systems that provides both spatial and energy resolution. The method combines atomic and tunneling techniques to supply a simple, yet quantitative and operational,…

Mesoscale and Nanoscale Physics · Physics 2018-11-22 Daniel Gruss , Chih-Chun Chien , Julio Barreiro , Massimiliano Di Ventra , Michael Zwolak

We show that the von Neumann's algorithm of reduction (i.e. the algorithm of calculating the density matrix of the observable subsystem from the density matrix of the closed quantum system) corresponds to the special approximation at which…

Quantum Physics · Physics 2007-05-23 N. K. Solovarov

In this paper we study the effect of non-trivial spatial topology on quantum entanglement by examining the degenerate ground states of a topologically ordered system on torus. Using the string-net (fixed-point) wave-function, we propose a…

Strongly Correlated Electrons · Physics 2016-08-17 Zhu-Xi Luo , Yu-Ting Hu , Yong-Shi Wu

Clarifying the interplay of interactions and disorder is fundamental to the understanding of many quantum systems, including superfluid helium in porous media, granular and thin-film superconductors, and light propagating in disordered…

Quantum Gases · Physics 2010-05-17 B. Deissler , M. Zaccanti , G. Roati , C. D'Errico , M. Fattori , M. Modugno , G. Modugno , M. Inguscio

To describe non-equilibrium transport processes in a quantum device with infinite baths, we propose to formulate the problems as a reduced-order problem. Starting with the Liouville-von Neumann equation for the density-matrix, the…

Mesoscale and Nanoscale Physics · Physics 2019-11-04 Weiqi Chu , Xiantao Li

We study the ground state properties of the one-dimensional extended Hubbard model at half-filling from the perspective of its particle reduced density matrix. We focus on the reduced density matrix of $2$ fermions and perform an analysis…

Strongly Correlated Electrons · Physics 2022-04-11 Diego L. B. Ferreira , Thiago O. Maciel , Reinaldo O. Vianna , Fernando Iemini

Quantum embedding methods enable the study of large, strongly correlated quantum systems by (usually self-consistent) decomposition into computationally manageable subproblems, in the spirit of divide-and-conquer methods. Among these,…

Strongly Correlated Electrons · Physics 2025-03-14 Alicia Negre , Fabian Faulstich , Raehyun Kim , Thomas Ayral , Lin Lin , Eric Cancès

Model reduction plays a critical role in system control, with established methods such as balanced truncation widely used for linear systems. However, extending these methods to nonlinear settings, particularly polynomial dynamical systems…

Dynamical Systems · Mathematics 2025-06-25 Xin Mao , Can Chen

Entanglement is a uniquely quantum resource giving rise to many quantum technologies. It is therefore important to detect and characterize entangled states, but this is known to be a challenging task, especially for multipartite mixed…

Quantum Physics · Physics 2025-12-25 Rain Lenny , Amit Te'eni , Bar Y. Peled , Avishy Carmi , Eliahu Cohen

Considering disordered electron systems we suggest a scheme that allows us to include an electron-electron interaction into a supermatrix sigma-model. The method is based on replacing the initial model of interacting electons by a fully…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 G. Schwiete , K. B. Efetov

Long-range order in quantum many-body systems is usually associated with equilibrium situations. Here, we experimentally investigate the quasicondensation of strongly-interacting bosons at finite momenta in a far-from-equilibrium case. We…

Motivated by recent experimental progress in the realization of synthetic gauge fields in systems of ultracold atoms, we consider interacting bosons on the dice lattice with half flux per plaquette. All bands of the non-interacting spectrum…

Quantum Gases · Physics 2014-07-23 Matjaz Payrits , Ryan Barnett

Quantum entanglement plays a key role in quantum computation and quantum information processing. It is of great significance to find efficient and experimentally friend separability criteria to detect entanglement. In this paper, we firstly…

Quantum Physics · Physics 2024-05-09 Yiding Wang , Tinggui Zhang , Xiaofen Huang , Shao-Ming Fei

We introduce a sequence of numerical tests that can determine the entanglement or separability of a state even when there is not enough information to completely determine its density matrix. Given partial information about the state in the…

Quantum Physics · Physics 2012-12-14 Federico M. Spedalieri

In this paper, we investigate the possibility of testing the weakly interacting massive particle (WIMP) dark matter (DM) models by applying the simplest phenomenological model which introduces an interaction term between dark energy (DE)…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-15 Wei Cheng , Yuan He , Jin-Wang Diao , Yu Pan , Jun Zeng , Jia-Wei Zhang

Entanglement in continuous-variable non-Gaussian states provides irreplaceable advantages in many quantum information tasks. However, the sheer amount of information in such states grows exponentially and makes a full characterization…