Gergely T. Zimanyi

Zero Droplet Stiffness Exponent $\theta$ is Revealed in Short Range Spin Glasses when Probed with Large Avalanches Induced by Long Range Interactions (2009)

Pazmandi, Ferenc, Zimanyi, Gergely T.

We probe the droplet excitations in short range spin glasses by adding a perturbative long range interaction that decays with distance as a power law: $J/r^{\sigma}$. It is shown that if the power...

Density of States and Critical Behavior of the Coulomb Glass (2008)

Surer, Brigitte, Katzgraber, Helmut G., Zimanyi, Gergely T., Allgood, Brandon A., Blatter, Gianni

We present zero-temperature simulations for the single-particle density of states of the Coulomb glass. Our results in three dimensions are consistent with the Efros and Shklovskii prediction for the...

Hysteretic memory effects in disordered magnets (2005)

Katzgraber, Helmut G., Zimanyi, Gergely T.

We study the return point as well as the complementary point memory effects numerically with paradigmatic models for random magnets and show that already simple systems with Ising spin symmetry can...

Extracting the intrinsic switching field distribution in perpendicular media: a comparative analysis (2005)

Winklhofer, Michael, Zimanyi, Gergely T.

We introduce a new method based on the first-order-reversal-curve (FORC) diagram to extract the intrinsic (microscopic) switching-field distribution (SFD) of perpendicular recording media (PRM). To...

Is the Multichannel Kondo Model Appropriate to Describe the Single Electron Transistor? (2000)

Zarand, Gergely, Zimanyi, Gergely T., Wilhelm, Frank

We investigate the low-temperature dynamics of single electron boxes and transistors close to their degeneracy point using renormalization group methods. We show that intermode scattering is a...

Phase-Locking of Vortex Lattices Interacting with Periodic Pinning (1999)

Reichhardt, Charles, Scalettar, Richard T., Zimanyi, Gergely T., Gronbech-Jensen, Niels

We examine Shapiro steps for vortex lattices interacting with periodic pinning arrays driven by AC and DC currents. The vortex flow occurs by the motion of the interstitial vortices through the...

Superconducting single-charge transistor in a tunable dissipative environment (1999)

Wilhelm, Frank K., Schoen, Gerd, Zimanyi, Gergely T.

We study a superconducting single-charge transistor, where the coherence of Cooper pair tunneling is destroyed by the coupling to a tunable dissipative environment. Sequential tunneling and...

Self-organized criticality in the hysteresis of the Sherrington - Kirkpatrick model (1999)

Pazmandi, Ferenc, Zarand, Gergely, Zimanyi, Gergely T.

We study hysteretic phenomena in random ferromagnets. We argue that the angle dependent magnetostatic (dipolar) terms introduce frustration and long range interactions in these systems. This makes it...

Superconducting SCT in a tunable dissipative environment (1999)

Frank K. Wilhelm, Gerd Schön, Gergely T. Zimanyi

We investigate a superconducting single-charge transistor, which is capacitively coupled to an ohmic 2-dimensional electron gas, whose resistivity can be controlled by a back gate and introduces an...

The Phase Diagram of Disordered Vortices from London Langevin Simulations (1998)

Van Otterlo, Anne, Scalettar, Richard T., Zimanyi, Gergely T.

We study the phase diagram of vortex matter in disordered type-II superconductors. We performed numerical simulations in the London Langevin approximation, using a new realistic representation of the...

A New Quantum Phase Transition in the Coupled Quantum Dots System (1997)

Andrei, Natan, Zimanyi, Gergely T., Schoen, Gerd

We study two quantum dots in the limit of strong dot-lead coupling and weak dot-dot tunneling. The model maps on Ising-coupled Kondo impurities. We argue that a new quantum critical fixed point...

The Superconductor-Insulator Transition in a Tunable Dissipative Environment (1997)

Wagenblast, Karl-Heinz, Van Otterlo, Anne, Schoen, Gerd, Zimanyi, Gergely T.

We study the influence of a tunable dissipative environment on the dynamics of Josephson junction arrays near the superconductor-insulator transition. The experimental realization of the environment...

Revisiting the Theory of Finite Size Scaling in Disordered Systems: \nu Can Be Less Than 2/d (1997)

Pazmandi, Ferenc, Scalettar, Richard T., Zimanyi, Gergely T.

For phase transitions in disordered systems, an exact theorem provides a bound on the finite size correlation length exponent: \nu_{FS}

Direct Mott Insulator-to-Superfluid Transition in the Presence of Disorder (1997)

Pazmandi, Ferenc, Zimanyi, Gergely T.

We introduce a new renormalization group theory to examine the quantum phase transitions upon exiting the insulating phase of a disordered, strongly interacting boson system. For weak disorder we...

Quantum Fluctuations and Resistivity of Thin Superconducting Wires (1996)

Zaikin, Andrei D., Golubev, Dmitrii S., Van Otterlo, Anne, Zimanyi, Gergely T.

We present a microscopic study of the quantum fluctuations of the superconducting order parameter in thin homogeneous superconducting wires at all temperatures below $T_C$. The rate of quantum phase...

The Moving Glass Phase of Dirty Type II Superconductors (1996)

Moon, Kyungsun, Scalettar, Richard T., Zimanyi, Gergely T.

We study numerically the motion of vortices in dirty type II superconductors. In two dimensions at strong driving currents, vortices form highly correlated ``static channels''. The static structure...

Theory for Quantum Spin and Vortex Glasses (1996)

Pazmandi, Ferenc, Zimanyi, Gergely T., Scalettar, Richard T.

We develop a theory for the quantum vortex glass, with both the coupling strengths and the site energies disordered. This model is closely related to XY spin glasses and bosons in random media. For...

Tunneling in the Electron Box in the Nonperturbative Regime (1994)

Falci, G., Heins, J., Schoen, Gerd, Zimanyi, Gergely T.

We study charging effects and tunneling in the single electron box. Tunneling mixes different charge states and in the nonperturbative regime the charge in the island may be strongly screened. When...