TY - JOUR

T1 - Anomalously large gap and induced out-of-plane spin polarization in magnetically doped 2D Rashba system

T2 - V-doped BiTeI

AU - Shikin, A. M.

AU - Rybkina, A. A.

AU - Klimovskikh, I. I.

AU - Tereshchenko, O. E.

AU - Bogomyakov, A. S.

AU - Kokh, K. A.

AU - Kimura, A.

AU - Skirdkov, P. N.

AU - Zvezdin, K. A.

AU - Zvezdin, A. K.

PY - 2017/6/1

Y1 - 2017/6/1

N2 - We have studied an energy gap opening at the Kramers point of quasi-2D Rashba semiconductor BiTeI with magnetic doping and influence of circularly polarized synchrotron radiation (SR) on the induced out-of-plane spin polarization of the gapped state. By means of angle- and spinresolved photoemission spectroscopy we have shown that below a Curie temperature, at 15-20 K, a spontaneous anomalously large energy gap at the Kramers point appears up to 90 and 125 meV depending on the V concentration (0.5 and 2%, respectively). Nevertheless, spin-resolved measurements show only a weak out-of-plane spin polarization both for the V 3d-resonances and the Rashba states owing to the presence of magnetic domains with opposite magnetic moments spontaneously generated without external magnetic field. Above a Curie temperature the out-of-plane spin polarization for the V 3d-resonances and 2D Rashba electron gas can be also induced by circularly polarized SR reversed in dependence on the chirality of circular polarization. It is followed by opening the energy gap at the Kramers point that confirms the induced magnetization. We connect the SR-induced out-of-plane spin polarization with a SR-derived hole generation leading to corresponding uncompensated spin accumulation in 2D Rashba electron gas with transferring the induced torque to the diluted V 3d-ions. The theoretical estimations corroborate well the experimental results.

AB - We have studied an energy gap opening at the Kramers point of quasi-2D Rashba semiconductor BiTeI with magnetic doping and influence of circularly polarized synchrotron radiation (SR) on the induced out-of-plane spin polarization of the gapped state. By means of angle- and spinresolved photoemission spectroscopy we have shown that below a Curie temperature, at 15-20 K, a spontaneous anomalously large energy gap at the Kramers point appears up to 90 and 125 meV depending on the V concentration (0.5 and 2%, respectively). Nevertheless, spin-resolved measurements show only a weak out-of-plane spin polarization both for the V 3d-resonances and the Rashba states owing to the presence of magnetic domains with opposite magnetic moments spontaneously generated without external magnetic field. Above a Curie temperature the out-of-plane spin polarization for the V 3d-resonances and 2D Rashba electron gas can be also induced by circularly polarized SR reversed in dependence on the chirality of circular polarization. It is followed by opening the energy gap at the Kramers point that confirms the induced magnetization. We connect the SR-induced out-of-plane spin polarization with a SR-derived hole generation leading to corresponding uncompensated spin accumulation in 2D Rashba electron gas with transferring the induced torque to the diluted V 3d-ions. The theoretical estimations corroborate well the experimental results.

KW - 2D Rashba system

KW - Angle-resolved photoemission spectroscopy

KW - Electronic structure

KW - Magnetically-doped 2D system

KW - Spin polarization

KW - Spin-resolved photoemission spectroscopy

KW - spin-resolved photoemission spectroscopy

KW - DIRAC-FERMION

KW - spin polarization

KW - TOPOLOGICAL INSULATOR

KW - TEXTURE

KW - electronic structure

KW - SURFACE

KW - FERROMAGNETISM

KW - magnetically-doped 2D system

KW - LAYER

KW - angle-resolved photoemission spectroscopy

UR - http://www.scopus.com/inward/record.url?scp=85021294560&partnerID=8YFLogxK

U2 - 10.1088/2053-1583/aa65bd

DO - 10.1088/2053-1583/aa65bd

M3 - Article

AN - SCOPUS:85021294560

VL - 4

JO - 2D Materials

JF - 2D Materials

SN - 2053-1583

IS - 2

M1 - 025055

ER -