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Related papers: Reflected entropy, symmetries and free fermions

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We investigate the question of whether the entropy and the Renyi entropies of the vacuum state reduced to a region of the space can be represented in terms of correlators in quantum field theory. In this case, the positivity relations for…

Quantum Physics · Physics 2014-11-20 H. Casini

We consider the entropy and decoherence in fermionic quantum systems. By making a Gaussian Ansatz for the density operator of a collection of fermions we study statistical 2-point correlators and express the entropy of a system fermion in…

High Energy Physics - Theory · Physics 2012-11-06 Tomislav Prokopec , Michael G. Schmidt , Jan Weenink

We develop a covariant formalism to investigate the mixed state entanglement structure of time-dependent boosted subsystems in $\textrm{T}\bar{\textrm{T}}$ deformed CFT$_2$s through the reflected entropy. To this end we utilize the…

High Energy Physics - Theory · Physics 2024-02-13 Debarshi Basu , Vinayak Raj

The entanglement entropy of two gapless non-interacting fermion subsystems is computed approximately in a way that avoids the introduction of replicas and a geometric interpretation of the reduced density matrix. We exploit the similarity…

Statistical Mechanics · Physics 2013-05-29 G. C. Levine , B. A. Friedman

We implement an extended version of reflection positivity (Wick-rotated unitarity) for invertible topological quantum field theories and compute the abelian group of deformation classes using stable homotopy theory. We apply these field…

High Energy Physics - Theory · Physics 2022-12-20 Daniel S. Freed , Michael J. Hopkins

The entanglement entropy of a subsystem of a quantum system is expressed, in the replica approach, through analytic continuation with respect to n of the trace of the n-th power of the reduced density matrix. This trace can be thought of as…

High Energy Physics - Theory · Physics 2008-12-18 Michele Caraglio , Ferdinando Gliozzi

We present a new class of local quenches described by mixed states, parameterized universally by two parameters. We compute the evolutions of entanglement entropy for both a holographic and Dirac fermion CFT in two dimensions. This turns…

High Energy Physics - Theory · Physics 2019-11-22 Arpan Bhattacharyya , Tadashi Takayanagi , Koji Umemoto

Entanglement and the R\'enyi entropies for Dirac fermions on 2 dimensional torus in the presence of chemical potential, current source, and topological Wilson loop are unified in a single framework by exhausting all the ingredients of the…

High Energy Physics - Theory · Physics 2022-01-19 Bom Soo Kim

We consider the universal part of entanglement entropy across a plane in flat space for a QFT, giving a non-perturbative expression in terms of a spectral function. We study the change in entanglement entropy under a deformation by a…

High Energy Physics - Theory · Physics 2015-06-22 Vladimir Rosenhaus , Michael Smolkin

In the framework of Quantum Field Theory, we provide a rigorous, operator algebraic notion of entanglement entropy associated with a pair of open double cones $O \subset \tilde O$ of the spacetime, where the closure of $O$ is contained in…

Mathematical Physics · Physics 2020-03-18 Roberto Longo , Feng Xu

We present a thorough analysis of the entanglement entropies related to different symmetry sectors of free quantum field theories (QFT) with an internal U(1) symmetry. We provide explicit analytic computations for the charged moments of…

High Energy Physics - Theory · Physics 2020-08-25 Sara Murciano , Giuseppe Di Giulio , Pasquale Calabrese

Identifying spatial quantum correlations in mixed states is challenging because thermal mixed-state contributions obscure the entanglement encoded in subsystem entropy. Here, we introduce the entanglement projected entropy, a diagnostic for…

Quantum Physics · Physics 2026-05-26 Jia-Wen Tao , Hui-Ke Jin

We study the universal scaling behavior of the entanglement entropy of critical theories in $2+1$ dimensions. We specially consider two fermionic scale-invariant models, free massless Dirac fermions and a model of fermions with quadratic…

Strongly Correlated Electrons · Physics 2015-02-24 Xiao Chen , Gil Young Cho , Thomas Faulkner , Eduardo Fradkin

A significant step towards a rigorous understanding of perturbative gravitational entropy was recently achieved by a series of works showing that a proper accounting of gauge invariance and observer degrees of freedom converts the Type III…

High Energy Physics - Theory · Physics 2025-07-09 Julian De Vuyst , Stefan Eccles , Philipp A. Hoehn , Josh Kirklin

A large class of strongly correlated quantum systems can be described in certain large-N limits by quadratic in field actions along with self-consistency equations that determine the two-point functions. We use the replica approach and the…

Strongly Correlated Electrons · Physics 2024-02-20 Siqi Shao , Yashar Komijani

We introduce a subsystem generalization of the spectral form factor via pseudo entropy, the von-Neumann entropy for the reduced transition matrix. We consider a transition matrix between the thermofield double state and its time-evolved…

High Energy Physics - Theory · Physics 2021-12-22 Kanato Goto , Masahiro Nozaki , Kotaro Tamaoka

Motivated by the appearance of a `reflection symmetry' in transport experiments and the absence of statistical periodicity in relativistic quantum field theories, we propose a series of relativistic composite fermion theories for the…

Strongly Correlated Electrons · Physics 2018-11-05 Hart Goldman , Eduardo Fradkin

Statistical formulations of thermodynamic entropy, such as those by Boltzmann and Gibbs, were originally developed for classical systems and are well understood in that context. However, the foundational aspects of quantum statistical…

Quantum Physics · Physics 2025-10-08 Smitarani Mishra , Shaon Sahoo

We provide a prescription to construct R\'{e}nyi and von Neumann entropy of a system of interacting fermions from a knowledge of its correlation functions. We show that R\'{e}nyi entanglement entropy of interacting fermions in arbitrary…

Statistical Mechanics · Physics 2024-01-09 Saranyo Moitra , Rajdeep Sensarma

Numerical studies of the reduced density matrix of a gapped spin-1/2 Heisenberg antiferromagnet on a two-leg ladder find that it has the same form as the Gibbs density matrix of a gapless spin-1/2 Heisenberg antiferromagnetic chain at a…

Strongly Correlated Electrons · Physics 2013-08-28 Xiao Chen , Eduardo Fradkin