162 citations · 1k across the 26 of their papers we have counts for
13 papers · 1 filter
Superfluid clusters, percolation and phase transitions in the disordered, two dimensional Bose-Hubbard model
Astrid Niederle, Heiko Rieger
The Bose glass (BG) phase is the Griffiths region of the disordered Bose Hubbard model (BHM), characterized by finite, quasi-superfluid clusters within a Mott insulating background…
Domain Growth in Random Magnets
Raja Paul, Sanjay Puri, Heiko Rieger
We study the kinetics of domain growth in ferromagnets with random exchange interactions. We present detailed Monte Carlo results for the nonconserved random-bond Ising model, whic…
Universal properties of shortest paths in isotropically correlated random potentials
Roland Schorr, Heiko Rieger
We consider the optimal paths in a -dimensional lattice, where the bonds have isotropically correlated random weights. These paths can be interpreted as the ground state configu…
Strongly disordered spin ladders
R. Mélin, Y. -C. Lin, P. Lajkó +2
The effect of quenched disorder on the low-energy properties of various antiferromagnetic spin ladder models is studied by a numerical strong disorder renormalization group method…
Ground states versus low-temperature equilibria in random field Ising chains
G. Schröder, T. Knetter, M. J. Alava +1
We discuss with the aid of random walk arguments and exact numerical computations the magnetization properties of one-dimensional random field chains. The ground state structure is…
Ground-States of Two Directed Polymers
V. T. Petaja, M. J. Alava, H. Rieger
Joint ground states of two directed polymers in a random medium are investigated. Using exact min-cost flow optimization the true two-line ground-state is compared with the single…
Random antiferromagnetic quantum spin chains: Exact results from scaling of rare regions
F. Igloi, R. Juhasz, H. Rieger
We study XY and dimerized XX spin-1/2 chains with random exchange couplings by analytical and numerical methods and scaling considerations. We extend previous investigations to dyn…
Critical exponents of random XX and XY chains: Exact results via random walks
H. Rieger, R. Juhasz, F. Igloi
We study random XY and (dimerized) XX spin-1/2 quantum spin chains at their quantum phase transition driven by the anisotropy and dimerization, respectively. Using exact expression…
Random quantum magnets with long-range correlated disorder: Enhancement of critical and Griffiths-McCoy singularities
H. Rieger, F. Igloi
We study the effect of spatial correlations in the quenched disorder on random quantum magnets at and near a quantum critical point. In the random transverse field Ising systems di…
Griffiths-McCoy Singularities in the Random Transverse-Field Ising Spin Chain
F. Igloi, R. Juhasz, H. Rieger
We consider the paramagnetic phase of the random transverse-field Ising spin chain and study the dynamical properties by numerical methods and scaling considerations. We extend our…
Average persistence in random walks
H. Rieger, F. Igloi
We study the first passage time properties of an integrated Brownian curve both in homogeneous and disordered environments. In a disordered medium we relate the scaling properties…
Application of a minimum cost flow algorithm to the three-dimensional gauge glass model with screening
J. Kisker, H. Rieger
We study the three-dimensional gauge glass model in the limit of strong screening by using a minimum cost flow algorithm, enabling us to obtain EXACT ground states for systems of l…
Ground state properties of solid-on-solid models with disordered substrates
H. Rieger, U. Blasum
We study the glassy super-rough phase of a class of solid-on-solid models with a disordered substrate in the limit of vanishing temperature by means of exact ground states, which w…