Spins in low-dimensional material systems: Transport, gate control and conversion

Professor Masashi Shiraishi, the Department of Electronic Science and Engineering, Kyoto University, Japan is in Leeds presenting his research.

Transport, control and conversion of spins in condensed matters have been pivotal concepts in spintronics. Spin transport is the most fundamental concept to realize spin-dependent phenomena, spin control mainly by gating enables information switching using a spin degree of freedom, and spin conversion allows detection of spins, a dissipative physical quantity. Whilst bulk metallic and semiconducting systems have been to date major material stages to realise the aforementioned concepts, low-dimensional materials systems such as atomically-flat two-dimensional materials [1-3], two-dimensional electron gases formed at an interface of a heterostructure [4,5], topologically-protected Dirac surface states in topological insulators [6,7] and ultrathin films [8] are becoming attractive materials stages to pursue novel spintronic concepts and phenomena. I will introduce the attractiveness of these new materials systems, cover an overview of the central achievements, and focus on recent investigation to pioneer novel spintronic physics in the low-dimensional materials systems.

[1] B. Raes, S.O. Valenzuela et al., “Determination of the spin-lifetime anisotropy in graphene using oblique spin precession”, Nature Commun. 7, 11444 (2016).
[2] S. Dushenko, M. Shiraishi et al., “Gate-tunable spin-charge conversion and the role of spinorbit interaction in graphene”, Phys. Rev. Lett. 116, 166102 (2016).
[3] A.W. Cummings, S. Roche et al., “Giant spin lifetime anisotropy in graphene induced by proximity effects”, Phys. Rev. Lett. 119, 206601 (2017).
[4] R. Ohshima, M. Shiraishi et al., “Strong evidence for d-electron spin transport at room temperature at a LaAlO3/SrTiO3 interface”, Nature Mater. 16, 609 (2017).
[5] E. Lesne, M. Bibes et al., “Highly efficient and tunable spin-to-charge conversion through Rashba coupling at oxide interface”, Nature Mater. 15, 1261 (2016).
[6] Y. Shiomi, E. Saitoh et al., Spin-electricity conversion induced by spin injection into topological insulators”, Phys. Rev. Lett. 113, 196601 (2014).
[7] Yuichiro Ando, M. Shiraishi et al., “Electrical detection of the spin polarization due to charge flow in the surface state of the topological insulator Bi1.5Sb0.5Te1.7Se1.3”, Nano Lett. 14, 6226 (2014).
[8] S. Dushenko, M. Shiraishi et al., “Tunable inverse spin Hall effect in nanometer-thick platinum films by ionic gating”, Nature Commun. 9, 3118 (2018).

Host: Dr Satoshi Sasaki