It is shown that the transverse susceptibility of a one-dimensional spin S Ising system can be calculated by combining linear response theory with the transfer matrix technique. Closed form expressions for infinite chains are obtained for S= 1 / 2 and S=1, and numerical results are displayed for S= 1 / 2 to S= 5 / 2 .
Exact expressions for the wave-number dependent longitudinal and transverse susceptibilities of the one-dimensional Ising model with competing interactions are obtained by combining the linear response theory with the transfer matrix method. The longitudinal susceptibility exhibits a characteristic wave-number dependence, while the transverse susceptibility is independent of wave-number. Special attention is paid to the condition under which the longitudinal susceptibility has a maximum value at nonzero wave-number. Furthermore, the phase diagram of a system with weakly coupled Ising chains is considered in connection with the one-dimensional susceptibility.
We study the transverse susceptibility of the fully frustrated antiferromagnetic Ising Δ-chain, extending Minami's transfer-matrix method to the transverse susceptibility of general-type Ising linear-chains [J. Phys. Soc. Jpn. 67 (1998), 2255]. For the transverse fields Γ1 in tip spin sites and Γ2 in bottom spin sites, we calculate zero-field transverse susceptibilities χxtip = lim Γ1 →0Mxtip/Γ1 and χxbottom = lim Γ2 →0Mxbottom/Γ2 while keeping the ratio Γ1/Γ2 fixed, where Mxtip (bottom) denotes the magnetization for tip (bottom) spin sites. Both the transverse susceptibilities follow Curie's law at low temperatures. We also calculate χxbottom(Γ1 > 0), the transverse susceptibility of the bottom spin chain under a finite tip-spin transverse field, to understand the Curie-type behavior in zero-field susceptibility. Using the second-order perturbation theory, we also discuss the Γ1 dependence of χxbottom (Γ1) at zero temperature.