arXiv:cond-mat/0509771 · The European Physical Journal B

Persistent currents in two dimensions: New regimes induced by the interplay between electronic correlations and disorder

Z. A. Németh, J.-L. Pichard

Published May 1, 2005• 4 citations

DOI: 10.1140/epjb/e2005-00170-y

Related papers

Effect of a lattice upon an interacting system of electrons in two dimensions: Breakdown of scaling and decay of persistent currents

Houman Falakshahi, Z. Á Németh, J.‐L. Pichard

arXiv:cond-mat/0402560The European Physical Journal BMay 1, 20044 citations

Persistent current in a one-dimensional correlated disordered ring

Isao Tomita

Physica A Statistical Mechanics and its ApplicationsMay 1, 20026 citations

Intermediate Regime between the Fermi Glass and the Mott Insulator in one Dimension

Dietmar Weinmann A, Jean‐Louis Pichard, Peter Schmitteckert +1 more

We consider the ground state reorganization driven by an increasing nearest neighbor repulsion U for spinless fermions in a strongly disordered ring. When U -> 0, the electrons form a glass with Anderson localized states. At half filling, a regular array of charges (Mott insulator) is pinned by the random substrate when U -> \infty. Between those two insulating limits, we show that there is an intermediate regime where the electron glass becomes more liquid before crystallizing. The liquid-like behavior of the density-density correlation function is accompanied by an enhancement of the persistent current.

arXiv:cond-mat/9905017May 3, 19990 citations

Persistent currents in interacting lattice models

Michael Abraham, Richard Berkovits

Physica A Statistical Mechanics and its ApplicationsNov 1, 19938 citations

Interacting fermions in two dimension in simultaneous presence of disorder and magnetic field

Saptarshi Mandal, Sanjay Gupta

We study the revival of Hofstadter butterfly due to the competition between disorder and electronic interaction using mean field approximation of unrestricted Hartree Fock method at zero temperature for two dimensional square and honeycomb lattices. Interplay of disorder and electronic correlation to nullify each other is corroborated by the fact that honeycomb lattice needs more strength of electronic correlation owing to its less co-ordination number which enhances the effect of disorder. The extent of revival of the butterfly is better in square lattice than honeycomb lattice due to higher coordination number. The effect of disorder and interaction is also investigated to study entanglement entropy and entanglement spectrum. We find that for honeycomb lattice area law of entanglement entropy is obeyed in all cases but for square lattice there is some departure from area law for larger subsystems. The entanglement spectrum have the reflection symmetry of the original butterfly of the Hofstadter spectrum. The interaction induces a gap in the entanglement spectrum as well conforming the correspondence between physical spectrum and entanglement spectrum. The effect of disorder closes the interaction induced gap in the entanglement spectrum establishing the nullification of interaction due to disorder and vice versa.

arXiv:1911.03466Journal of Physics Condensed MatterMar 14, 20221 citation

The Interplay of Localization and Interactions in Quantum Many-Body Systems

Shankar Iyer

Disorder and interactions both play crucial roles in quantum transport. Decades ago, Mott showed that electron-electron interactions can lead to insulating behavior in materials that conventional band theory predicts to be conducting. Soon thereafter, Anderson demonstrated that disorder can localize a quantum particle through the wave interference phenomenon of Anderson localization. Although interactions and disorder both separately induce insulating behavior, the interplay of these two ingredients is subtle and often leads to surprising behavior at the periphery of our current understanding. Modern experiments probe these phenomena in a variety of contexts (e.g. disordered superconductors, cold atoms, photonic waveguides, etc.); thus, theoretical and numerical advancements are urgently needed. In this thesis, we report progress on understanding two contexts in which the interplay of disorder and interactions is especially important. The first is the so-called “dirty” or random boson problem. In the past decade, a strong-disorder renormalization group (SDRG) treatment by Altman, Kafri, Polkovnikov, and Refael has raised the possibility of a new unstable fixed point governing the superfluid-insulator transition in the one-dimensional dirty boson problem. This new critical behavior may take over from the weak-disorder criticality of Giamarchi and Schulz when disorder is sufficiently strong. We analytically determine the scaling of the superfluid susceptibility at the strong-disorder fixed point and connect our analysis to recent Monte Carlo simulations by Hrahsheh and Vojta. We then shift our attention to two dimensions and use a numerical implementation of the SDRG to locate the fixed point governing the superfluid-insulator transition there. We identify several universal properties of this transition, which are fully independent of the microscopic features of the disorder. The second focus of this thesis is the interplay of localization and interactions in systems with high energy density (i.e., far from the usual low energy limit of condensed matter physics). Recent theoretical and numerical work indicates that localization can survive in this regime, provided that interactions are sufficiently weak. Stronger interactions can destroy localization, leading to a so-called many-body localization transition. This dynamical phase transition is relevant to questions of thermalization in isolated quantum systems: it separates a many-body localized phase, in which localization prevents transport and thermalization, from a conducting (“ergodic”) phase in which the usual assumptions of quantum statistical mechanics hold. Here, we present evidence that many-body localization also occurs in quasiperiodic systems that lack true disorder.

May 30, 20130 citations