8 papers
Low Energy Singlets in the Heisenberg Kagome Antiferromagnet
Ran Budnik, Assa Auerbach
The spin half Heisenberg antiferromagnet on the Kagome lattice, is mapped by Contractor Renormalization to a Spin-Pseudospin Hamiltonian on the triangular superlattice. Variational…
Andreev Peaks and Massive Magnons in Cuprate SNS junctions
Assa Auerbach, Ehud Altman
The projected SO(5) theory (pSO(5)) is used to resolve the puzzle of two distinct energy gaps in high T Superconductor-Normal-Superconductor junctions. Counter to conventional…
Appearance of spontaneous macroscopic magnetization at the superconducting transition of YBCO
R. Carmi, E. Polturak, G. Koren +1
We report the observation of a weak spontaneous magnetic field appearing at the transition temperature of into the superconducting state. The effect is obser…
Coulomb interactions and delocalization in quantum Hall constrictions
Leonid P. Pryadko, Efrat Shimshoni, Assa Auerbach
We study a geometry-dependent effect of long-range Coulomb interactions on quantum Hall (QH) tunneling junctions. In an X-shaped geometry, duality relates junctions with opening an…
Hall Resistivity and Dephasing in the Quantum Hall Insulator
Leonid P. Pryadko, Assa Auerbach
The longstanding problem of the Hall resistivity rho(x,y) in the Hall insulator phase is addressed using four-lead Chalker-Coddington networks. Electron interaction effects are int…
Quantum Magnetism Approaches to Strongly Correlated Electrons
A. Auerbach
Problems of strongly interacting electrons can be greatly simplified by reducing them to effective quantum spin models. The initial step is renormalization of the Hamiltonian into…