TY - JOUR

T1 - Collective electronic excitations on the MgB2(0001) surfaces

AU - Silkin, Vyacheslav M.

AU - Chulkov, Evgenii V.

AU - Echenique, Pedro M.

PY - 2019

Y1 - 2019

N2 - The surface excitation spectra of the B-terminated and Mg-terminated MgB2(0001) surfaces are studied in the ab initio time-dependent density functional theory approach. The band structure of both these surfaces is fully included into evaluation of the surface response function using a linear response approach. We find that different surface electronic structures for these surface terminations result in very different surface collective electronic excitations. Due to a number of surface states and peculiarity of the MgB2 dielectric properties several surface plasmons, such as surface plasmon, interband surface plasmon, acoustic surface plasmon, and others have been found. We trace their evolution with momentum transfer change on both surfaces. Whereas at vanishing momentum transfers the plasmons in both systems can be understood considering the bulk MgB2 dielectric function, upon momentum increase the collective excitations present very different behavior. We relay such behavior to the differences in the surface electronic structure of the studied terminations.

AB - The surface excitation spectra of the B-terminated and Mg-terminated MgB2(0001) surfaces are studied in the ab initio time-dependent density functional theory approach. The band structure of both these surfaces is fully included into evaluation of the surface response function using a linear response approach. We find that different surface electronic structures for these surface terminations result in very different surface collective electronic excitations. Due to a number of surface states and peculiarity of the MgB2 dielectric properties several surface plasmons, such as surface plasmon, interband surface plasmon, acoustic surface plasmon, and others have been found. We trace their evolution with momentum transfer change on both surfaces. Whereas at vanishing momentum transfers the plasmons in both systems can be understood considering the bulk MgB2 dielectric function, upon momentum increase the collective excitations present very different behavior. We relay such behavior to the differences in the surface electronic structure of the studied terminations.

KW - MgB

KW - Surface plasmon

KW - Surface states

KW - MgB2

UR - http://www.scopus.com/inward/record.url?scp=85071610494&partnerID=8YFLogxK

U2 - 10.1016/bs.aiq.2019.07.001

DO - 10.1016/bs.aiq.2019.07.001

M3 - Article

AN - SCOPUS:85071610494

VL - 80

SP - 147

EP - 174

JO - Advances in Quantum Chemistry

JF - Advances in Quantum Chemistry

SN - 0065-3276

ER -