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Related papers: Extendibility of Fermionic Gaussian States

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Exploring universal entanglement structure in many-body systems is both fundamental and challenging, particularly when the system undergoes non-unitary operations. In this work, we uncover a universal mechanism for realizing maximal…

Quantum Physics · Physics 2025-12-19 Jiyuan Fang , Qicheng Tang , Xueda Wen

This paper considers the extension of the non-Markovian stochastic approach for quantum open systems strongly coupled to a fermionic bath, to the models in which the system operators commute with the fermion bath. This technique can also be…

Quantum Physics · Physics 2013-04-19 Xinyu Zhao , Wufu Shi , Lian-Ao Wu , Ting Yu

We introduce regular series expansion for weakly- and moderately-correlated fermionic systems, based on Fluctuating Local Field approach. The method relies on the explicit account of leading fluctuating mode(s) and is therefore suitable for…

Strongly Correlated Electrons · Physics 2024-12-25 Ya. S. Lyakhova , S. D. Semenov , A. I. Lichtenstein , A. N. Rubtsov

We investigate the subsystem Schatten distance, trace distance and fidelity between the quasiparticle excited states of the free and the nearest-neighbor coupled fermionic and bosonic chains and the ferromagnetic phase of the spin-1/2 XXX…

Statistical Mechanics · Physics 2022-08-11 Jiaju Zhang , M. A. Rajabpour

Tensor network methods have progressed from variational techniques based on matrix-product states able to compute properties of one-dimensional condensed-matter lattice models into methods rooted in more elaborate states such as projected…

Strongly Correlated Electrons · Physics 2021-08-23 C. Krumnow , L. Veis , J. Eisert , Ö. Legeza

In this paper, we investigate the bound states of $2+1$ fermionic trimers on a three-dimensional lattice at strong coupling. Specifically, we analyze the discrete spectrum of the associated three-body discrete Schr\"odinger operator…

Spectral Theory · Mathematics 2025-02-04 Janikul Abdullaev , Ahmad Khalkhuzhaev , Shokhrukh Yu. Kholmatov

We consider a free fermion chain with uniform nearest-neighbor hopping and let it evolve from an arbitrary initial state with a fixed macroscopic number of particles. We then prove that, at a sufficiently large and typical time, the…

Statistical Mechanics · Physics 2026-04-13 Hal Tasaki

System of Dirac fermions with random-varying mass is studied in detail. We reformulate the system by transfer-matrix formalism. Eigenvalues and wave functions are obtained numerically for various configurations of random telegraphic mass…

Disordered Systems and Neural Networks · Physics 2009-10-31 Koujin Takeda , Toyohiro Tsurumaru , Ikuo Ichinose , Masaomi Kimura

We study a model for a quantum critical point in two spatial dimensions between a semimetallic phase, characterized by a stable quadratic Fermi node, and an ordered phase, in which the spectrum develops a band gap. The quantum critical…

Strongly Correlated Electrons · Physics 2020-09-02 Shouryya Ray , Matthias Vojta , Lukas Janssen

We extend the study of finite-entanglement scaling from one-dimensional gapless models to two-dimensional systems with a Fermi surface. In particular, we show that the entanglement entropy of a contractible spatial region with linear size…

Strongly Correlated Electrons · Physics 2024-01-11 Quinten Mortier , Ming-Hao Li , Jutho Haegeman , Nick Bultinck

We establish tight upper and lower bounds for the Entanglement of Formation of an arbitrary two-mode Gaussian state employing necessary properties of Gaussian channels. Both bounds are strictly given by the Entanglement of Formation of…

Quantum Physics · Physics 2014-06-09 Fernando Nicacio , Marcos Cesar de Oliveira

We consider $m$ spinless Fermions in $l > m$ degenerate single-particle levels interacting via a $k$-body random interaction with Gaussian probability distribution and $k <= m$ in the limit $l$ to infinity (the embedded $k$-body random…

Condensed Matter · Physics 2009-10-31 Luis Benet , Thomas Rupp , Hans A. Weidenmueller

De Finetti theorems show how sufficiently exchangeable states are well-approximated by convex combinations of i.i.d. states. Recently, it was shown that in many quantum information applications a more relaxed de Finetti reduction (i.e. only…

Quantum Physics · Physics 2020-01-27 Cécilia Lancien , Andreas Winter

We review the theory of continuous-variable entanglement with special emphasis on foundational aspects, conceptual structures, and mathematical methods. Much attention is devoted to the discussion of separability criteria and entanglement…

Quantum Physics · Physics 2009-07-02 Gerardo Adesso , Fabrizio Illuminati

We discuss classical algorithms for approximating the largest eigenvalue of quantum spin and fermionic Hamiltonians based on semidefinite programming relaxation methods. First, we consider traceless $2$-local Hamiltonians $H$ describing a…

Quantum Physics · Physics 2019-10-08 Sergey Bravyi , David Gosset , Robert Koenig , Kristan Temme

We present a new variational method for investigating the ground state and out of equilibrium dynamics of quantum many-body bosonic and fermionic systems. Our approach is based on constructing variational wavefunctions which extend Gaussian…

Quantum Physics · Physics 2018-03-14 Tao Shi , Eugene Demler , J. Ignacio Cirac

The concept of symmetric extendibility has recently drawn attention in the context of tolerable error rates in quantum cryptography, where it can be used to decide whether quantum states shared between two parties can be purified by means…

Quantum Physics · Physics 2009-12-09 Kedar S. Ranade

In the problem of asymptotic binary i.i.d. state discrimination, the optimal asymptotics of the type I and the type II error probabilities is in general an exponential decrease to zero as a function of the number of samples; the set of…

Quantum Physics · Physics 2023-01-18 Gergely Bunth , Gábor Maróti , Milán Mosonyi , Zoltán Zimborás

Tensor network quantum states are powerful tools for strongly correlated systems, tailored to capture local correlations such as in ground states with entanglement area laws. When applying tensor network states to interacting fermionic…

Strongly Correlated Electrons · Physics 2025-01-10 Ang-Kun Wu , Benedikt Kloss , Wladislaw Krinitsin , Matthew T. Fishman , J. H. Pixley , E. M. Stoudenmire

We reconsider the Gram-Hadamard bound as it is used in constructive quantum field theory and many body physics to prove convergence of Fermionic perturbative expansions. Our approach uses a recursion for the amplitudes of the expansion,…

Mathematical Physics · Physics 2016-05-25 Martin Lohmann