Transverse susceptibility of the one-dimensional antiferromagnetic XY model. Application to Cs2CoCl4

Abstract

The transverse susceptibility of the one-dimensional antiferromagnetic $\mathrm{XY}$ model is calculated for a sequence of finite chains with periodic boundary conditions. The infinite-chain susceptibility is obtained by extrapolation, and good convergence is found for most temperatures. The results are compared with the $c$-axis susceptibility of ${\mathrm{Cs}}_2$Co${\mathrm{Cl}}_4$, which has been measured over the temperature interval 40 mK-4.2 K. The agreement is excellent, confirming that this compound can be well approximated by a set of weakly coupled antiferromagnetic $\mathrm{XY}$ chains.