Nanometer-scale exchange interactions between spin centers in diamond

Abstract

Exchange interactions between isolated pairs of spin centers in diamond have been calculated, based on an accurate atomistic electronic structure for diamond and any impurity atoms, for spin-center separations of up to 2 nm. The exchange interactions exceed dipolar interactions for spin-center separations of less than 3 nm. NV- spin centers, which involve two lattice sites which differ from the host, interact very differently depending on the relative orientations of the symmetry axis of the spin center and the radius vector connecting the pair. Exchange interactions between transition-metal dopants behave similarly to those of NV- centers. The Mn-Mn exchange interaction decays with a much longer length scale than the Cr-Cr and Ni-Ni exchange interactions, exceeding dipolar interactions for Mn-Mn separations of less than 5 nm. Calculations of these highly anisotropic and spin-center-dependent interactions provide the potential for the design of spin-spin interactions for novel nanomagnetic structures.