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We consider generic interacting chain of qubits, which are coupled at the edges to baths of fixed polarizations. We can determine the nonequilibrium steady states, described by the fixed point of the Lindblad Master Equation. Under rather…

Quantum Physics · Physics 2015-06-12 Vladislav Popkov , Roberto Livi

We study the transport and equilibration properties of a classical Heisenberg chain, whose couplings are random variables drawn from a one-parameter family of power-law distributions. The absence of a scale in the couplings makes the system…

Statistical Mechanics · Physics 2023-10-09 Adam J. McRoberts , Federico Balducci , Roderich Moessner , Antonello Scardicchio

A strongly coupled spin chain can mediate long-distance effective couplings or entanglement between remote qubits, and can be used as a quantum data bus. We study how the fidelity of a spin-1/2 Heisenberg chain as a spin bus is affected by…

Quantum Physics · Physics 2013-04-25 Sangchul Oh , Yun-Pil Shim , Jianjia Fei , Mark Friesen , Xuedong Hu

We introduce a numerical method of the adaptive time-dependent density-matrix renormalization-group to compute one-dimensional quantum spin systems with periodic boundary condition. We check our algorithm to study the dynamic correlation in…

Statistical Mechanics · Physics 2011-06-01 Jie Ren

We analytically and numerically study spin transport in a one-dimensional Heisenberg model in linear-response regime at infinite temperature. It is shown that as the anisotropy parameter Delta is varied spin transport changes from ballistic…

Strongly Correlated Electrons · Physics 2011-06-03 Marko Znidaric

We study the finite-temperature dynamical spin susceptibility of the one-dimensional (generalized) anisotropic Heisenberg model within the hydrodynamic regime of small wave vectors and frequencies. Numerical results are analyzed using the…

Strongly Correlated Electrons · Physics 2012-09-10 J. Herbrych , R. Steinigeweg , P. Prelovšek

We investigate the low-energy properties of antiferromagnetic quantum XXZ spin chains with couplings following two-letter aperiodic sequences, by an adaptation of the Ma-Dasgupta-Hu renormalization-group method. For a given aperiodic…

Strongly Correlated Electrons · Physics 2007-05-23 André P. Vieira

We predict the emergence of turbulent scaling in the quench dynamics of the two-dimensional Heisenberg model for a wide range of initial conditions and model parameters. In the isotropic Heisenberg model, we find that the spin-spin…

Statistical Mechanics · Physics 2021-08-11 Joaquin F. Rodriguez-Nieva

The one dimensional spin-1/2 Heisenberg antiferromagnet in a weak magnetic field h is studied using the bosonization method. We derive a set of renormalization group equations. The fixed point is reached when the field is scaled to the…

Strongly Correlated Electrons · Physics 2009-10-31 Ping Sun , D. Schmeltzer

The low temperature phase diagram of 1D disordered quantum systems like charge or spin density waves, superfluids and related systems is considered by a full finite T renormalization group approach, presented here for the first time. At…

Strongly Correlated Electrons · Physics 2009-11-07 Andreas Glatz , Thomas Nattermann

We study the distribution of finite size pseudo-critical points in a one-dimensional random quantum magnet with a quantum phase transition described by an infinite randomness fixed point. Pseudo-critical points are defined in three…

Disordered Systems and Neural Networks · Physics 2008-03-12 Ferenc Iglói , Yu-Cheng Lin , Heiko Rieger , Cécile Monthus

We demonstrate that the concept of quantum typicality allows for significant progress in the study of real-time spin dynamics and transport in quantum magnets. To this end, we present a numerical analysis of the spin-current autocorrelation…

Strongly Correlated Electrons · Physics 2014-03-31 Robin Steinigeweg , Jochen Gemmer , Wolfram Brenig

We study the critical behavior of Ising quantum magnets with broadly distributed random couplings (J), such that $P(\ln J) \sim |\ln J|^{-1-\alpha}$, $\alpha>1$, for large $|\ln J|$ (L\'evy flight statistics). For sufficiently broad…

Statistical Mechanics · Physics 2009-10-31 D. Karevski , Y-C. Lin , H. Rieger , N. Kawashima , F. Iglói

The temperature dependence of the static magnetic susceptibility of exchange-disordered antiferromagnetic Heisenberg spin-1/2 finite chains with an odd number of spins is investigated as a function of size and type of disorder in the…

Strongly Correlated Electrons · Physics 2009-01-29 C. M. Chaves , Thereza Paiva , J. d'Albuquerque e Castro , Belita Koiller

Bulk magnetism in solids is fundamentally quantum mechanical in nature. Yet in many situations, including our everyday encounters with magnetic materials, quantum effects are masked, and it often suffices to think of magnetism in terms of…

Strongly Correlated Electrons · Physics 2009-11-13 N. B. Christensen , H. M. Ronnow , D. F. McMorrow , A. Harrison , T. G. Perring , M. Enderle , R. Coldea , L. P. Regnault , G. Aeppli

Generalised hydrodynamics predicts universal ballistic transport in integrable lattice systems when prepared in generic inhomogeneous initial states. However, the ballistic contribution to transport can vanish in systems with additional…

Statistical Mechanics · Physics 2017-07-14 Marko Ljubotina , Marko Znidaric , Tomaz Prosen

S=1/2 quantum spin chains and ladders with random exchange coupling are studied by using an effective low-energy field theory and transfer matrix methods. Effects of the nonlocal correlations of exchange couplings are investigated…

Disordered Systems and Neural Networks · Physics 2007-05-23 K. Takeda , I. Ichinose

We develop a finite-temperature perturbation theory for quasi-one-dimensional quantum spin systems, in the manner suggested by H.J. Schulz (1996) and use this formalism to study their dynamical response. The corrections to the random-phase…

Strongly Correlated Electrons · Physics 2009-11-07 Marc Bocquet

We study the thermodynamics of one-dimensional quantum spin-1/2 Heisenberg ferromagnetic system with random antiferromagnetic impurity bonds. In the dilute impurity limit, we generalize the modified spin-wave theory for random spin chains,…

Disordered Systems and Neural Networks · Physics 2009-11-07 Xin Wan , Kun Yang , R. N. Bhatt

We study the distribution of dynamical quantities in various one-dimensional, disordered models the critical behavior of which is described by an infinite randomness fixed point. In the {\it disordered contact process}, the quenched…

Disordered Systems and Neural Networks · Physics 2015-06-18 Róbert Juhász