TY - JOUR
T1 - Magnetism, spin texture, and in-gap states
T2 - Atomic specialization at the surface of oxygen-deficient SrTiO3
AU - Altmeyer, Michaela
AU - Jeschke, Harald O.
AU - Hijano-Cubelos, Oliver
AU - Martins, Cyril
AU - Lechermann, Frank
AU - Koepernik, Klaus
AU - Santander-Syro, Andrés F.
AU - Rozenberg, Marcelo J.
AU - Valentí, Roser
AU - Gabay, Marc
N1 - Funding Information:
We would like to thank Vladislav Borisov for performing test calculations with QuantumEspresso. We especially thank Domenico di Sante, Silvia Picozzi, Michael Sing, and Ralph Claessen for useful discussions. M. A., H. O. J., and R. V. gratefully acknowledge the Deutsche Forschungsgemeinschaft (DFG) for financial support through SFB/TR 49 and FOR 1346. M. A. and R. V. were partially supported by the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara under National Science Foundation Grant No. PHY11-25915. A. F. S.-S. and M. G. acknowledge support from the Institut Universitaire de France and from the French National Research Agency (ANR) (Project LACUNES No. ANR-13-BS04-0006-01).
Publisher Copyright:
© 2016 American Physical Society.
PY - 2016/4/14
Y1 - 2016/4/14
N2 - Motivated by recent spin- and angular-resolved photoemission (SARPES) measurements of the two-dimensional electronic states confined near the (001) surface of oxygen-deficient SrTiO3, we explore their spin structure by means of ab initio density functional theory (DFT) calculations of slabs. Relativistic nonmagnetic DFT calculations display Rashba-like spin winding with a splitting of a few meV and when surface magnetism on the Ti ions is included, bands become spin-split with an energy difference ∼100 meV at the Γ point, consistent with SARPES findings. While magnetism tends to suppress the effects of the relativistic Rashba interaction, signatures of it are still clearly visible in terms of complex spin textures. Furthermore, we observe an atomic specialization phenomenon, namely, two types of electronic contributions: one is from Ti atoms neighboring the oxygen vacancies that acquire rather large magnetic moments and mostly create in-gap states; another comes from the partly polarized t2g itinerant electrons of Ti atoms lying further away from the oxygen vacancy, which form the two-dimensional electron system and are responsible for the Rashba spin winding and the spin splitting at the Fermi surface.
AB - Motivated by recent spin- and angular-resolved photoemission (SARPES) measurements of the two-dimensional electronic states confined near the (001) surface of oxygen-deficient SrTiO3, we explore their spin structure by means of ab initio density functional theory (DFT) calculations of slabs. Relativistic nonmagnetic DFT calculations display Rashba-like spin winding with a splitting of a few meV and when surface magnetism on the Ti ions is included, bands become spin-split with an energy difference ∼100 meV at the Γ point, consistent with SARPES findings. While magnetism tends to suppress the effects of the relativistic Rashba interaction, signatures of it are still clearly visible in terms of complex spin textures. Furthermore, we observe an atomic specialization phenomenon, namely, two types of electronic contributions: one is from Ti atoms neighboring the oxygen vacancies that acquire rather large magnetic moments and mostly create in-gap states; another comes from the partly polarized t2g itinerant electrons of Ti atoms lying further away from the oxygen vacancy, which form the two-dimensional electron system and are responsible for the Rashba spin winding and the spin splitting at the Fermi surface.
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U2 - 10.1103/PhysRevLett.116.157203
DO - 10.1103/PhysRevLett.116.157203
M3 - Article
AN - SCOPUS:84963877227
SN - 0031-9007
VL - 116
JO - Physical Review Letters
JF - Physical Review Letters
IS - 15
M1 - 157203
ER -