• Shin, S.
• Kobayashi, K.
• Sakano, M.
• Miyamoto, K.
• Kimura, A.
• Miyahara, H.
• Okuda, T.
• Taniguchi, M.
• Koizumi, K.
• Kaneko, Y.
• Onose, Y.
• Namatame, H.
• Sonobe, T.
• Arita, R.
• Murakami, Y.
• Bahramy, Mohammad Saeed
• Tokura, Y.
• Kumai, R.
• Ishizaka, K.
• Shimojima, T.
• Murakawa, H.
• Nagaosa, N.

Abstract

There has been increasing interest in phenomena emerging from relativistic electrons in a solid, which have a potential impact on spintronics and magnetoelectrics. One example is the Rashba effect, which lifts the electron-spin degeneracy as a consequence of spin–orbit interaction under broken inversion symmetry. A high-energy-scale Rashba spin splitting is highly desirable for enhancing the coupling between electron spins and electricity relevant for spintronic functions. Here we describe the finding of a huge spin–orbit interaction effect in a polar semiconductor composed of heavy elements, BiTeI, where the bulk carriers are ruled by large Rashba-like spin splitting. The band splitting and its spin polarization obtained by spin- and angle-resolved photoemission spectroscopy are well in accord with relativistic first-principles calculations, confirming that the spin splitting is indeed derived from bulk atomic configurations. Together with the feasibility of carrier-doping control, the giant-Rashba semiconductor BiTeI possesses excellent potential for application to various spin-dependent electronic functions.

Topics

• impedance spectroscopy
• semiconductor
• spin polarization