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Related papers: Entanglement in composite free-fermion systems

200 papers

The structure of entanglement in the ground state of the harmonic chain is studied. A class of two-mode squeezed states, useful for this purpose, is identified. The entanglement of the local modes at the ends of the chain, after tracing out…

Quantum Physics · Physics 2026-05-11 Andrew Steane , Haru Ishizaka

The ground state entanglement of the system, both in discrete-time and continuous-time cases, is quantified through the linear entropy. The result shows that the entanglement increases as the interaction between the particles increases in…

The system of two interacting bosons in a two-dimensional harmonic trap is compared with the system consisting of two noninteracting fermions in the same potential. In particular, we discuss how the properties of the ground state of the…

Quantum Gases · Physics 2018-03-21 Pere Mujal , Artur Polls , Bruno Juliá-Díaz

We study the time evolution of entanglement created by local or extended excitations upon the ground state of a free-fermion chain. A single particle or hole excitation produces a single bit of excess entropy for large times and subsystem…

Statistical Mechanics · Physics 2021-10-15 Viktor Eisler

We study the melting of a domain wall in free-fermion chains, where the periodic variation of the hopping amplitudes gives rise to a band structure. It is shown that the entanglement grows logarithmically in time, and the prefactor is…

Statistical Mechanics · Physics 2025-10-15 Viktor Eisler

We study the relationship between bipartite entanglement, subsystem particle number and topology in a half-filled free fermion system. It is proposed that the spin-projected particle numbers can distinguish the quantum spin Hall state from…

Mesoscale and Nanoscale Physics · Physics 2014-02-25 Y. F. Zhang , L. Sheng , R. Shen , Rui Wang , D. Y. Xing

Free fermions on Hamming graphs $H(d,q)$ are considered and the entanglement entropy for two types of subsystems is computed. For subsets of vertices that form Hamming subgraphs, an analytical expression is obtained. For subsets…

Quantum Physics · Physics 2021-03-30 Pierre-Antoine Bernard , Nicolas Crampe , Luc Vinet

Entanglement is one of the most fundamental features of quantum systems. In this work, we obtain the entanglement spectrum and entropy of Floquet noninteracting fermionic lattice models and build their connections with Floquet topological…

Quantum Physics · Physics 2022-12-07 Longwen Zhou

Topological phases of matter remain a focus of interest due to their unique properties -- fractionalisation, ground state degeneracy, and exotic excitations. While some of these properties can occur in systems of free fermions, their…

Strongly Correlated Electrons · Physics 2018-03-06 Konstantinos Meichanetzidis , Christopher J. Turner , Ashk Farjami , Zlatko Papić , Jiannis K. Pachos

This topical review article reports rapid progress on the generalization and application of entanglement in non-Hermitian free-fermion quantum systems. We begin by examining the realization of non-Hermitian quantum systems through the…

Quantum Physics · Physics 2026-01-14 Li-Mei Chen , Yao Zhou , Shuai A. Chen , Peng Ye

We study the ground-state entanglement Hamiltonian of free nonrelativistic fermions for semi-infinite domains in one dimension. This is encoded in the two-point correlations projected onto the subsystem, an operator that commutes with the…

Statistical Mechanics · Physics 2025-03-17 Viktor Eisler

We build upon work by C. K. Law [Phys. Rev. A 71, 034306 (2005)] to show in general that the entanglement between two fermions largely determines the extent to which the pair behaves like an elementary boson. Specifically, we derive upper…

Quantum Physics · Physics 2013-05-29 Christopher Chudzicki , Olufolajimi Oke , William K. Wootters

We observe that the many-body eigenstates of any quadratic, fermionic Hamiltonian with sublattice symmetry have quantized entanglement entropies between the sublattices: the entanglement comes in multiple singlets. Moreover, such systems…

Quantum Physics · Physics 2023-02-27 Henrik Wilming , Tobias J. Osborne

We study the entanglement properties of a closed chain of harmonic oscillators that are coupled via a translationally invariant Hamiltonian, where the coupling acts only on the position operators. We consider the ground state and thermal…

Quantum Physics · Physics 2009-11-07 K. Audenaert , J. Eisert , M. B. Plenio , R. F. Werner

We study the entanglement in momentum space of the ground state of a disordered one-dimensional fermion lattice model with attractive interaction. We observe two components in the entanglement spectrum, one of which is related to…

Disordered Systems and Neural Networks · Physics 2017-12-05 Bing-Tian Ye , Zhao-Yu Han , Liang-Zhu Mu , Heng Fan

We study the properties of the entanglement spectrum in gapped non-interacting non-Hermitian systems, and its relation to the topological properties of the system Hamiltonian. Two different families of entanglement Hamiltonians can be…

Mesoscale and Nanoscale Physics · Physics 2020-01-06 Loïc Herviou , Nicolas Regnault , Jens H. Bardarson

Free Fermions on vertices of distance-regular graphs are considered. Bipartition are defined by taking as one part all vertices at a given distance from a reference vertex. The ground state is constructed by filling all states below a…

Mathematical Physics · Physics 2020-10-09 Nicolas Crampe , Krystal Guo , Luc Vinet

There is an intimate relation between entanglement entropy and Riemann surfaces. This fact is explicitly noticed for the case of quadratic fermionic Hamiltonians with finite range couplings. After recollecting this fact, we make a…

Mathematical Physics · Physics 2016-05-02 F. Ares , J. G. Esteve , F. Falceto , A. R. de Queiroz

We examine the entanglement entropy of the even half of a translationally invariant finite chain or lattice in its ground state. This entropy measures the entanglement between the even and odd halves (each forming a "comb" of $n/2$ sites)…

Quantum Physics · Physics 2011-04-26 Raul Rossignoli , Norma Canosa , Juan Mauricio Matera

Entanglement and stabilizer entropy are both involved in the onset of complex behavior in quantum many-body systems. Their interplay is at the root of complexity of simulability, scrambling, thermalization and typicality. In this work, we…

Quantum Physics · Physics 2025-09-16 Jovan Odavić , Michele Viscardi , Alioscia Hamma