arXiv subjects

A. G. Abanov

Publications and source records attributed to A. G. Abanov.

21 records · Page 2Linked to original sources

arXiv1997

Tunneling and orthogonality catastrophe in the topological mechanism of superconductivity

We compute the angular dependence of the order parameter and tunneling amplitude in a model exhibiting topological superconductivity and sketch its derivation as a model of a doped Mott insulator. We show that ground states differing by an odd number of particles are orthogonal and the order parameter is in the d-representation, although the gap in the electronic spectrum has no nodes. We also develop an operator algebra, that allowes one to compute off-diagonal correlation functions.

cond-mat.supr-con↗

arXiv1996

Period doubling in the 2D Antiferromagnet. New gauge-fields and their anomalies

We construct an effective gauge field theory model describing a 2D quantum antiferromagnet in the flux phase ground state. Due to period doubling the number of gauge fields is four rather than the naively expected single one. These additional gauge fields correspond to field configurations in which the flux is staggered, which should be taken into account to enforce single occupancy within the magnetic unit cell. We calculate a new type of quantum anomaly, present in such a model. In particular this leads to a generalized local flux hypothesis, which is tested numerically.

cond-mat.str-el↗

arXiv1994

Enhancement of Anisotropy due to Fluctuations in Quasi-One-Dimensional Antiferromagnets

It is shown that the observed anisotropy of magnetization at high magnetic fields in RbMnBr3 , a quasi-one-dimensional antiferromagnet on a distorted stacked triangular lattice, is due to quantum and thermal fluctuations. These fluctuations are taken into account in the framework of linear spin-wave theory in the region of strong magnetic fields. In this region the divergent one-dimensional integrals are cut off by magnetic field and the bare easy-plane anisotropy. Logarithmical dependence on the cutoff leads to the "enhancement" of the anisotropy in magnetization. Comparison between magnetization data and our theory with parameters obtained from neutron scattering experiments has been done.

cond-mat↗