Spin Currents in a Coherent Exciton Gas

• Main Authors: High, A. A., Hammack, A. T., Leonard, J. R., Yang, Sen, Butov, L. V., Ostatnický, T., Vladimirova, M., Kavokin, A. V., Liew, Timothy Chi Hin, Campman, K. L., Gossard, A. C.
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2017
• Subjects: Excitons; Spin currents
• Online Access: https://hdl.handle.net/10356/85902; http://hdl.handle.net/10220/43887
• Institution: Nanyang Technological University

We report the observation of spin currents in a coherent gas of indirect excitons. The realized long-range spin currents originate from the formation of a coherent gas of bosonic pairs—a new mechanism to suppress the spin relaxation. The spin currents result in the appearance of a variety of polarization patterns, including helical patterns, four-leaf patterns, spiral patterns, bell patterns, and periodic patterns. We demonstrate control of the spin currents by a magnetic field. We also present a theory of coherent exciton spin transport that describes the observed exciton polarization patterns and indicates the trajectories of the spin currents.