Nanoscale structure of the orbital magnetic moment of a single dopant spin in a semiconductor*

The localized electron spin of a single impurity in a semiconductor is a promising system to realize quantum information schemes. In this work we investigate the orbital contribution to the magnetic moment originated from the spin-orbit induced circulating current [1] associated with the ground state of a single magnetic impurity in III-V semiconductors. In this project we developed a formalism employing Green's functions obtained by the Koster-Slater technique [2] with a sp³d⁵s^* empirical tight-binding Hamiltonian [3] to describe the host material. We calculated the circulating current and orbital moments of a single Mn dopant in GaAs. The spin-correlated orbital moments originates from the hybridization between the Mn(d⁵) spin-polarized electrons and the As dangling bonds leading to t₂-symmetric triplet acceptor states in the band-gap above the valence band edge.
[1] van Bree, J. and Silov, A.Yu and Koenraad, P.M. and Flatté, M. E., PRL 112, 187201 (2014).
[2] Tang, J.M. and Flatté, M.E., PRL. 92, 047201 (2004).
[3] Jancu, J.M. and Scholz, R. and Beltram, F. and Bassani, F., PRB 57, 6493 (1998).