Dissipationless Circulating Currents and Fringe Magnetic Fields Near a Single Spin Embedded in a Two-Dimensional Electron Gas

The combination of spin-orbit coupling with broken spatial inversion symmetry in semiconductors (e.g. zinc-blende quantum-wells and surfaces) and localized spin states originated from a single magnetic defect is a promising system to realize future semiconductor spintronics devices [1]. We present a theory of dissipationless circulating current induced by a magnetic defect in a two-dimensional electron gas with both Bychkov-Rashba and Dresselhaus spin-orbit coupling [2]. The shape and spatial extent of these dissipationless circulating currents depend dramatically on the relative strengths of spin-orbit fields with differing spatial symmetry, offering the potential to use an electric gate to manipulate nanoscale magnetic fields and couple magnetic defects. The spatial structure of the fringing magnetic field emerging from the current is calculated and provides a direct way to measure the spin-orbit fields of the host, as well as the defect spin orientation, through scanning nanoscale magnetometry [3].

[1] Wolfowicz, G., Heremans, F.J., Anderson, C.P. et al. Nat Rev Mater 6, 906–925 (2021). 

[2] Berman, D.H. and Flatté, M. E., Phys. Rev. Lett. 105, 157202 (2010).

[3] Casola, F. and van der Sar, T. and Yacoby, A. Nature Reviews Materials, 3(1), 17088 (2018).