Disordered quantum antiferromagnetism in doped semiconductors: Density of states approach

We present a theoretical study of the exchange interaction in a system of spatially disordered magnetic moments. A typical example of such a system is an impurity semiconductor whose magnetic properties are associated with the exchange interaction of the impurity atoms. In this study, we consider the case of antiferromagnetic exchange interaction, which we describe by the Heisenberg Hamiltonian. To calculate the magnetic properties of the disordered system, we employ the joint density of states method. Our calculations demonstrate good quantitative agreement with the experimental dependence of the Si:P magnetic susceptibility on temperature in a wide range of impurity concentrations and temperatures. The obtained results may be important for a deeper understanding of the metal-dielectric transition nature.