Author(s): Zhou, M (Zhou, Ma)

Source: PHYSICAL REVIEW B Volume: 103 Issue: 15 Article Number: 155429 DOI: 10.1103/PhysRevB.103.155429 Published: APR 27 2021

Abstract: By using the single-band and multiband effective Hamiltonian for monolayer XSe (X=In,Ga), we calculate the density-density response function of monolayer XSe (X=In,Ga) and study its plasmon dispersion within the random-phase approximation. At long wavelengths (q -> 0), plasmon dispersion shows the local classical behavior omega = omega(0)root q. Although, monolayer XSe (X=In,Ga) has a nonparabolic "Mexican hat" topmost valence band dispersion which is so different from the parabolic band structure in two-dimensional electron gas, the corresponding density dependence of the plasmon energy is still of the form omega(0) proportional to root(n) (n is the carrier concentration) as in a conventional two-dimensional electron gas (2DEGs). However, the Fermi energy (vertical bar mu vertical bar) dependence of the plasmon energy is of the form omega(0) proportional to vertical bar mu vertical bar(1/4), which is different from the conventional 2DEGs (omega(0) proportional to root(vertical bar mu vertical bar) over bar).

Accession Number: WOS:000646765400007

ISSN: 2469-9950

eISSN: 2469-9969

Full Text: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.103.155429