Orbitally quantized density-wave states perturbed from equilibrium

TL;DR

This paper explores how magnetic field changes induce a critical, metastable state in orbitally quantized density-wave systems, leading to persistent currents and potential three-dimensional chiral metallic behavior.

Contribution

It introduces a theoretical framework for the critical state in orbitally quantized density-wave phases, analogous to vortex states in superconductors, supported by experimental verification.

Findings

Verification of the critical state in alpha-(BEDT-TTF)MHg(SCN)4 salts

Identification of persistent currents in the bulk of the material

Proposal of a three-dimensional chiral metal phase

Abstract

We consider the effect that a change in the magnetic induction B has in causing an orbitally quantized field-induced spin- or charge density wave (FISDW or FICDW) state to depart from thermodynamic equilibrium. The competition between elastic forces of the density wave (DW) and pinning leads to the realization of a critical state that is in many ways analogous to that realized within the vortex state of type II superconductors. Such a critical state has been verified experimentally in charge-transfer salts of the composition alpha-(BEDT-TTF)MHg(SCN)4, but should be a generic property of all orbitally quantized DW phases. The metastable state consists of a balance between the DW pinning force and the Lorentz force on extended currents associated with drifting cyclotron orbits, resulting in the establishment of persistent currents throughout the bulk and to the possibly of a three-dimensional `chiral metal' that extends deep into the interior of a crystal.