Drift transport of helical spin coherence with tailored spin–orbit interactions

• Published in: Nature communications 2016-03, Vol.7 (1), p.10722-10722, Article 10722
• Main Authors: Kunihashi, Y., Sanada, H., Gotoh, H., Onomitsu, K., Kohda, M., Nitta, J., Sogawa, T.
• Format: Article
• Language: English
• Subjects: 639/301/119/1000; 639/766/119/1001; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms10722

Most future information processing techniques using electron spins in non-magnetic semiconductors will require both the manipulation and transfer of spins without their coherence being lost. The spin–orbit effective magnetic field induced by drifting electrons enables us to rotate the electron spins in the absence of an external magnetic field. However, the fluctuations in the effective magnetic field originating from the random scattering of electrons also cause undesirable spin decoherence, which limits the length scale of the spin transport. Here we demonstrate the drift transport of electron spins adjusted to a robust spin structure, namely a persistent spin helix. We find that the persistent spin helix enhances the spatial coherence of drifting spins, resulting in maximized spin decay length near the persistent spin helix condition. Within the enhanced distance of the spin transport, the transport path of electron spins can be modulated by employing time-varying in-plane voltages. Spin-orbit effects in non-magnetic semiconductors allow for the manipulation of electronic spins in the absence of an applied magnetic field. Here, the authors exploit a persistent spin helix state in single quantum wells to enhance the coherence length of electronic drift transport.