• 文献标题:   Collective excitations in spin-polarized bilayer graphene
  • 文献类型:   Article
  • 作  者:   MEN NV, KHANH NQ, PHUONG DTK
  • 作者关键词:   plasmon, graphene, spinpolarization
  • 出版物名称:   JOURNAL OF PHYSICSCONDENSED MATTER
  • ISSN:   0953-8984 EI 1361-648X
  • 通讯作者地址:  
  • 被引频次:   3
  • DOI:   10.1088/1361-648X/abcf01
  • 出版年:   2021

▎ 摘  要

We calculate the plasmon frequency omega and damping rate gamma of plasma oscillations in a spin-polarized BLG system. Using the long wavelength approximation for dynamical dielectric function, we obtain an analytical expression for plasmon frequency showing that degree of spin polarization P has negligible effect on the long wavelength plasmon frequency. Numerical calculations demonstrate that the plasmon frequency increases (decreases) noticeably (slightly) with the increase in spin polarization in large (small) wave-vector q region. We also find that the damping rate and the shape of gamma as a function of q depend strongly on P. The increase in carrier density decreases significantly both plasmon frequency and damping rate independently of the spin polarization. The numerically calculated critical wave vector, at which the plasmon dispersion curve hits the edge of electron-hole continuum, decreases with P and can be used to experimentally determine the degree of spin polarization.