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Related papers: Multifractality in non-unitary random dynamics

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We investigate the dynamics of two-dimensional quantum spin systems under the combined effect of random unitary gates and local projective measurements. When considering steady states, a measurement-induced transition occurs between two…

Statistical Mechanics · Physics 2020-10-16 Xhek Turkeshi , Rosario Fazio , Marcello Dalmonte

We introduce and study a class of models of free fermions hopping between neighbouring sites with random Brownian amplitudes. These simple models describe stochastic, diffusive, quantum, unitary dynamics. We focus on periodic boundary…

Statistical Mechanics · Physics 2019-04-17 M. Bauer , D. Bernard , T. Jin

Random bond Hamiltonians of the $\pi$ flux state on the square lattice are investigated. It has a special symmetry and all states are paired except the ones with zero energy. Because of this, there are always zero-modes. The states near…

Condensed Matter · Physics 2009-10-28 Yasuhiro Hatsugai , Xiao-Gang Wen , Mahito Kohmoto

We present a comprehensive study of the destruction of quantum multifractality in the presence of perturbations. We study diverse representative models displaying multifractality, including a pseudointegrable system, the Anderson model and…

Chaotic Dynamics · Physics 2015-10-01 R. Dubertrand , I. García-Mata , B. Georgeot , O. Giraud , G. Lemarié , J. Martin

We propose a non-linear, hybrid quantum-classical scheme for simulating non-equilibrium dynamics of strongly correlated fermions described by the Hubbard model in a Bethe lattice in the thermodynamic limit. Our scheme implements…

Quantum Physics · Physics 2016-09-14 J. M. Kreula , S. R. Clark , D. Jaksch

Here we present a non-Hermitian framework for modeling state-vector collapse under unified dynamics described by Schr\"odinger's equation. Under the premise of non-Hermitian Hamiltonian dynamics, we argue that collapse has to occur when the…

Quantum Physics · Physics 2025-05-30 Luis E. F. Foa Torres , Stephan Roche

Entanglement transitions in quantum dynamics present a novel class of phase transitions in non-equilibrium systems. When a many-body quantum system undergoes unitary evolution interspersed with monitored random measurements, the…

Quantum Physics · Physics 2021-10-08 Oliver Lunt , Marcin Szyniszewski , Arijeet Pal

We explore the dynamical phases of unitary Clifford circuits with variable-range interactions, coupled to a monitoring environment. We investigate two classes of models, distinguished by the action of the unitary gates, which either are…

Quantum Physics · Physics 2022-06-08 Shraddha Sharma , Xhek Turkeshi , Rosario Fazio , Marcello Dalmonte

We study free fermion systems under adaptive quantum dynamics consisting of unitary gates and projective measurements followed by corrective unitary operations. We further introduce a classical flag for each site, allowing for an active or…

Quantum Physics · Physics 2025-04-09 Vikram Ravindranath , Zhi-Cheng Yang , Xiao Chen

Many-body quantum dynamics defined on a spatial lattice and in discrete time -- either as stroboscopic Floquet systems or quantum circuits -- has been an active area of research for several years. Being discrete in space and time, a natural…

Quantum Physics · Physics 2024-11-04 Pieter W. Claeys , Austen Lamacraft

Multifractal dimensions allow for characterizing the localization properties of states in complex quantum systems. For ergodic states the finite-size versions of fractal dimensions converge to unity in the limit of large system size.…

Statistical Mechanics · Physics 2019-10-30 Arnd Bäcker , Masudul Haque , Ivan M. Khaymovich

We investigate the problem of evaluating the output probabilities of Clifford circuits with nonstabilizer product input states. First, we consider the case when the input state is mixed, and give an efficient classical algorithm to…

Quantum Physics · Physics 2019-10-25 Kaifeng Bu , Dax Enshan Koh

We investigate the interplay between unitary and non-unitary driven many-body dynamics in (1+1)-dimensional quantum critical systems described by conformal field theory (CFT). By formulating a coherent state approach, we demonstrate that…

Strongly Correlated Electrons · Physics 2025-09-29 Bastien Lapierre , Pietro Pelliconi , Shinsei Ryu , Julian Sonner

Nonstabilizerness, or quantum magic, presents a valuable resource in quantum error correction and computation. We study the dynamics of locally injected magic in unitary Clifford circuits, where the total magic is conserved. However, the…

Quantum Physics · Physics 2025-11-27 Mircea Bejan , Pieter W. Claeys , Jiangtian Yao

A numerical approach is presented that allows to compute nonequilibrium steady state properties of strongly correlated quantum many-body systems. The method is imbedded in the Keldysh Green's function formalism and is based upon the idea of…

Strongly Correlated Electrons · Physics 2011-10-26 Michael Knap , Wolfgang von der Linden , Enrico Arrigoni

The electronic behavior in graphene under arbitrary uniaxial deformations, such as foldings or flexural fields is studied by including in the Dirac equation pseudoelectromagnetic fields. General foldings are thus studied by showing that…

Mesoscale and Nanoscale Physics · Physics 2023-03-23 Abdiel E. Champo , Gerardo G. Naumis

Through a combination of rigorous analytical derivations and extensive numerical simulations, this work reports an exotic multifractal behavior, dubbed "logarithmic multifractality", in effectively infinite-dimensional systems undergoing…

Disordered Systems and Neural Networks · Physics 2025-03-04 Weitao Chen , Olivier Giraud , Jiangbin Gong , Gabriel Lemarié

We study measurement-induced phase transitions in quantum circuits consisting of kicked Ising models with postselected weak measurements, whose dynamics can be mapped onto a classical dynamical system. For a periodic (Floquet) non-unitary…

Quantum Physics · Physics 2025-07-08 Bastien Lapierre , Liang-Hong Mo , Shinsei Ryu

We investigate the generation of quantum states and unitary operations that are ``random'' in certain respects. We show how to use such states to estimate the average fidelity, an important measure in the study of implementations of quantum…

Quantum Physics · Physics 2007-05-23 Christoph Dankert

How much does local and time-periodic dynamics resemble a random unitary? In the present work we address this question by using the Clifford formalism from quantum computation. We analyse a Floquet model with disorder, characterised by a…