Derivation of effective low-energy Hamiltonians for chemically complex materials from first principles

Abstract

List of Figures xiii List of Tables xviii2.1 Quasi-one-dimensional, temperature-dependent magnetic susceptibility of coupled spin-1/2 Heisenberg antiferromagnetic chains using the CRPA (Equation 2.14) and one-dimensional data from Eggert et al. [8,9] (in the place of χ chain ). The interchain coupling values are represented as a sum of all interchain couplings in the system, J ⊥i , divided by the intrachain coupling, J. In this case, the interchain couplings are all unfrustrated (c.f. Figure 2.2a). The dashed lines indicate that the CRPA is valid only above the temperature at which the system orders due to the interchain coupling (k B T i J ⊥i