Quasi-One-Dimensional Spin-Density-Wave States with Two Kinds of Periodic Potentials and a Interchain Misfit

TL;DR

This paper investigates the phase diagram of quasi-one-dimensional spin density wave states under two types of periodic potentials, revealing various ordered and disordered phases influenced by temperature and chemical potential.

Contribution

It introduces a classical phase variable approach to analyze SDW states with incommensurate wave vectors and multiple potentials, mapping out a comprehensive phase diagram.

Findings

Identification of multiple SDW phases including commensurate and incommensurate states.

Discovery of a disordered phase at certain temperature and chemical potential ranges.

Characterization of phase transitions influenced by interchain misfit and potentials.

Abstract

Spin density wave (SDW) states of a quasi-one-dimensional system with an incommensurate wave vector perpendicular to the chain have been studied in the presence of two kinds of commensurate potentials, which originate in a quarter-filled band and dimerization along the chain. In terms of a phase variable of the SDW order parameter, we treat classically the two-dimensional Hamiltonian, which includes both acoustic excitations with long wave length and a vortex excitation with short wave length. A phase diagram on the plane of temperature and chemical potential (where the latter corresponds to the deviation of the transverse wave vector from the commensurate one) exhibits a variety of states given by the commensurate SDW state without charge density, the commensurate SDW state with charge density, the incommensurate SDW state and the disordered state.