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In this paper, we study a holographic description of weak measurements in conformal field theories (CFTs). Weak measurements can be viewed as a soft projection that interpolates between an identity operator and a projection operator, and…

High Energy Physics - Theory · Physics 2023-12-29 Xinyu Sun , Shao-Kai Jian

While non-Hermitian bulk systems and their sensitivity to boundary conditions have been extensively studied, how a non-Hermitian boundary affects the entanglement structure of Hermitian critical systems remains largely unexplored. Here we…

Quantum Physics · Physics 2025-10-20 Yao Zhou , Peng Ye

We study bipartite post measurement entanglement entropy after selective measurements in quantum chains. We first study the quantity for the critical systems that can be described by conformal field theories. We find a connection between…

Strongly Correlated Electrons · Physics 2017-02-01 Khadijeh Najafi , M. A. Rajabpour

We study an inhomogeneous critical Ising chain in a transverse field whose couplings decay exponentially from the center. In the strong inhomogeneity limit we apply Fisher's renormalization group to show that the ground state is formed by…

Strongly Correlated Electrons · Physics 2022-11-17 Nadir Samos Sáenz de Buruaga , Silvia N. Santalla , Javier Rodríguez-Laguna , Germán Sierra

The resilience of quantum entanglement to a classicality-inducing environment is tied to fundamental aspects of quantum many-body systems. The dynamics of entanglement has recently been studied in the context of measurement-induced…

Quantum Physics · Physics 2020-10-21 Oliver Lunt , Arijeet Pal

We study the entanglement entropy of the quantum trajectories of a free fermion chain under continuous monitoring of local occupation numbers. We propose a simple theory for entanglement entropy evolution from disentangled and highly…

Statistical Mechanics · Physics 2019-08-28 Xiangyu Cao , Antoine Tilloy , Andrea De Luca

Adaptive quantum circuits-where a quantum many-body state is controlled using measurements and conditional unitary operations-are a powerful paradigm for state preparation and quantum error correction tasks. They can support two types of…

Quantum Physics · Physics 2025-06-30 Thomas Iadecola , Justin H. Wilson , J. H. Pixley

We calculate the entanglement entropy of strongly correlated low-dimensional fermions in metallic, superfluid and antiferromagnetic insulating phases. The entanglement entropy reflects the degrees of freedom available in each phase for…

Strongly Correlated Electrons · Physics 2009-11-11 V. V. França , K. Capelle

We numerically study the entanglement dynamics of free fermions on a cubic lattice with potential disorder following a quantum quench. We focus, in particular, on the metal-insulator transition at a critical disorder strength and compare…

Disordered Systems and Neural Networks · Physics 2020-11-20 Y. Zhao , D. Feng , Y. Hu , S. Guo , J. Sirker

Consider a generic quantum spin chain that can be mapped to free quadratic fermions via Jordan-Wigner (JW) transformation. In the presence of arbitrary boundary magnetic fields, this Hamiltonian is no longer a quadratic Hamiltonian after JW…

Strongly Correlated Electrons · Physics 2022-06-15 Arash Jafarizadeh , M. A. Rajabpour

Finding new critical states of matter is an important subject in modern many-body physics. Here we study the effect of measurement and postselection on the critical ground state of a Luttinger liquid theory and show that it can lead to…

Quantum Physics · Physics 2023-05-09 Xinyu Sun , Hong Yao , Shao-Kai Jian

We study the ground-state entanglement Hamiltonian of several disjoint intervals for the massless Dirac fermion on the half-line. Its structure consists of a local part and a bi-local term that couples each point to another one in each…

Statistical Mechanics · Physics 2023-02-08 Federico Rottoli , Sara Murciano , Erik Tonni , Pasquale Calabrese

We study two entanglement measures in a large family of isotropic many-body states including incompressible quantum Hall liquids and quantum critical systems: the logarithmic negativity (LN), and mutual information (MI). For pure states,…

Strongly Correlated Electrons · Physics 2025-12-09 Chia-Chuan Liu , Juliette Geoffrion , William Witczak-Krempa

We study the entanglement entropies in one-dimensional open critical systems, whose effective description is given by a conformal field theory with boundaries. We show that for pure-state systems formed by the ground state or by the excited…

Statistical Mechanics · Physics 2013-09-02 L. Taddia , J. C. Xavier , F. C. Alcaraz , G. Sierra

"Weak measurements" -- involving a weak unitary interaction between a quantum system and a meter followed by a projective measurement -- are investigated when the system has a non-Hermitian Hamiltonian. We show in particular how the…

Quantum Physics · Physics 2012-12-21 A. Matzkin

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 explore the nonunitary dynamics of $(2+1)$-dimensional free fermions and show that the obtained steady state is critical regardless the strength of the nonunitary evolution. Numerical results indicate that the entanglement entropy has a…

Statistical Mechanics · Physics 2021-05-13 Qicheng Tang , Xiao Chen , W. Zhu

We study the dynamics under continuous measurements for free fermions in a quasiperiodic potential by using the Aubry-Andr\'{e}-Harper model with hopping rate $J$ and potential strength $V$. On the basis of the quantum trajectory method, we…

Quantum Gases · Physics 2025-08-20 Toranosuke Matsubara , Kazuki Yamamoto , Akihisa Koga

The effects of different forms of weak measurements on the nature of the measurement induced phase transition are theoretically studied in hybrid random quantum circuits of qubits. We use a combination of entanglement measures, ancilla…

Quantum Physics · Physics 2024-12-10 Kemal Aziz , Ahana Chakraborty , J. H. Pixley

We study the properties of mixed states obtained from eigenstates of many-body lattice Hamiltonians after tracing out part of the lattice. Two scenarios emerge for generic systems: (i) the diagonal entropy becomes equivalent to the…

Statistical Mechanics · Physics 2015-06-04 Lea F. Santos , Anatoli Polkovnikov , Marcos Rigol