Research output: Contribution to journal › Article › peer-review
Origin of two-dimensional electronic states at Si- And Gd-terminated surfaces of GdRh2Si2 (001). / Vyazovskaya, A. Yu.; Otrokov, M. M.; Koroteev, Yu. M.; Kummer, K.; Güttler, M.; Vyalikh, D. V.; Chulkov, E. V.
In: Physical Review B, Vol. 100, No. 7, 075140, 20.08.2019.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Origin of two-dimensional electronic states at Si- And Gd-terminated surfaces of GdRh2Si2 (001)
AU - Vyazovskaya, A. Yu.
AU - Otrokov, M. M.
AU - Koroteev, Yu. M.
AU - Kummer, K.
AU - Güttler, M.
AU - Vyalikh, D. V.
AU - Chulkov, E. V.
PY - 2019/8/20
Y1 - 2019/8/20
N2 - We present a first-principles study of the GdRh2Si2(001) surface electronic structure. Two surfaces, Si- and Gd-terminated, are considered. The origin of the two-dimensional (2D) electronic states at both terminations is investigated by tracing the band structure evolution by going from individual Si, Rh, and Gd atomic layers to (non)stoichiometric ultrathin films and, finally, to thicker GdRh2Si2 slabs. We find the conic-like (Dirac-like) resonance state located in the vicinity of the Γ point at the Si termination to form via the Tamm mechanism and explain the reasons for the differences in dispersion and energy position of the resonance states at the Si and Gd terminations. Then, we show how the butterfly-like dispersion of the Shockley state, residing in the bulk projected band gap near the M point, appears due to the interaction of the bands localized in the surface and subsurface Gd-Si-Rh-Si blocks of the Si termination. Also, a giant sign-alternating atomic relaxation near both the Si- and Gd-terminated surfaces is revealed and its effect on the dispersion and energy position of the 2D states is discussed. In this way we shed light on the origin of the 2D states and explain their dispersion seen in angle-resolved photoemission spectroscopy experiments.
AB - We present a first-principles study of the GdRh2Si2(001) surface electronic structure. Two surfaces, Si- and Gd-terminated, are considered. The origin of the two-dimensional (2D) electronic states at both terminations is investigated by tracing the band structure evolution by going from individual Si, Rh, and Gd atomic layers to (non)stoichiometric ultrathin films and, finally, to thicker GdRh2Si2 slabs. We find the conic-like (Dirac-like) resonance state located in the vicinity of the Γ point at the Si termination to form via the Tamm mechanism and explain the reasons for the differences in dispersion and energy position of the resonance states at the Si and Gd terminations. Then, we show how the butterfly-like dispersion of the Shockley state, residing in the bulk projected band gap near the M point, appears due to the interaction of the bands localized in the surface and subsurface Gd-Si-Rh-Si blocks of the Si termination. Also, a giant sign-alternating atomic relaxation near both the Si- and Gd-terminated surfaces is revealed and its effect on the dispersion and energy position of the 2D states is discussed. In this way we shed light on the origin of the 2D states and explain their dispersion seen in angle-resolved photoemission spectroscopy experiments.
KW - Crystal atomic structure
KW - Dispersions
KW - ELECTRONIC STATES
KW - electronic structure
KW - Energy gap
KW - gadolinium
KW - Gadolinium compounds
KW - Photoelectron spectroscopy
KW - Rhodium compounds
KW - Silicon
KW - Ultrathin films
KW - SUPERCONDUCTIVITY
KW - QUANTUM
KW - BEHAVIOR
KW - TEMPERATURE
KW - YBRH2SI2
UR - http://www.scopus.com/inward/record.url?scp=85072063317&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.100.075140
DO - 10.1103/PhysRevB.100.075140
M3 - Article
AN - SCOPUS:85072063317
VL - 100
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 7
M1 - 075140
ER -
ID: 49497807