Quasiparticles of spatially anisotropic triangular antiferromagnets in a magnetic field

TL;DR

This paper investigates the spectral properties of anisotropic triangular antiferromagnets in a magnetic field, revealing quasiparticle modes that explain unusual experimental features in Cs_2CuCl_4.

Contribution

It introduces a weak-interchain-coupling approach combined with exact chain solutions to identify quasiparticles in anisotropic triangular antiferromagnets under magnetic fields.

Findings

Identification of quasiparticle modes with distinctive features

Quantitative explanation of experimental observations in Cs_2CuCl_4

Revelation of anomalous incommensurate ordering and high-energy modes

Abstract

The spectral properties of the spin-1/2 Heisenberg antiferromagnet on an anisotropic triangular lattice in a magnetic field are investigated using a weak-interchain-coupling approach combined with exact solutions of a chain. Dominant modes induced by interchain interactions in a magnetic field behave as quasiparticles which show distinctive features such as anomalous incommensurate ordering and high-energy modes. In terms of them, various unusual features observed in the anisotropic triangular antiferromagnet Cs_2CuCl_4 in a magnetic field are quantitatively explained in a unified manner.