Switching the persistent spin helix’s orientation in gate-controlled GaAs double quantum wells

Employing time-resolved Kerr rotation microscopy, we demonstrate electrical control over the orientation of the persistent spin helix in a double Ga⁢As quantum well structure equipped with independent front and back gates. We map spin polarization patterns under varying gate voltages and show that coordinated tuning of two gates enables switching between two orthogonal persistent spin helix (PSH) orientations. This is achieved by inverting the Rashba spin-orbit coupling parameter while maintaining a stable electron density, thus overcoming the leakage-current limitations inherent to single-gate systems. A Fourier analysis of the spin maps provides quantitative extraction of spin-orbit coupling strengths, revealing that the Dresselhaus term remains nearly constant while the Rashba parameter is controlled by the difference between the gate voltages. These results establish dual-gate quantum well architectures as an effective platform for precise PSH manipulation and highlight their potential for spintronic applications such as spin-logic devices and long-distance spin interconnects.

S. Chander, B.W. Grobecker, A.V. Poshakinskiy, S. Anghel, T. Mano, J.N. Moore, G. Yusa, M. Betz, “Switching the persistent spin helix’s orientation in gate-controlled GaAs double quantum wells”, Phys. Rev. Applied 25, 034064 (2026).