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This content will become publicly available on January 22, 2019

Title: Nonlocal optical response in topological phase transitions in the graphene family

We investigate the electromagnetic response of staggered two-dimensional materials of the graphene family, including silicene, germanene, and stanene, as they are driven through various topological phase transitions using external fields. Utilizing Kubo formalism, we compute their optical conductivity tensor taking into account the frequency and wave vector of the electromagnetic excitations, and study its behavior over the full electronic phase diagram of the materials. In particular, we find that the resonant behavior of the nonlocal Hall conductivity is strongly affected by the various topological phases present in these materials. We also consider the plasmon excitations in the graphene family and find that nonlocality in the optical response can affect the plasmon dispersion spectra of the various phases. Here, we find a regime of wave vectors for which the plasmon relations for phases with trivial topology are essentially indistinguishable, while those for phases with nontrivial topology are distinct and are redshifted as the corresponding Chern number increases. Finally, the expressions for the conductivity components are valid for the entire graphene family and can be readily used by others.
 [1] ; ORCiD logo [2] ; ORCiD logo [2] ;  [3]
  1. Inst. de Ciencia de Materiales de Madrid, Madrid (Spain). Materials Science Factory; Univ. of South Florida, Tampa, FL (United States). Dept. of Physics; GISC-Grupo Interdisciplinar de Sistemas Complejos, Madrid (Spain)
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. Univ. of South Florida, Tampa, FL (United States). Dept. of Physics
Publication Date:
Report Number(s):
Journal ID: ISSN 2475-9953; PRMHAR
Grant/Contract Number:
AC52-06NA25396; FG02-06ER46297
Accepted Manuscript
Journal Name:
Physical Review Materials
Additional Journal Information:
Journal Volume: 2; Journal Issue: 1; Journal ID: ISSN 2475-9953
American Physical Society (APS)
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Laboratory Directed Research and Development (LDRD) Program
Country of Publication:
United States
36 MATERIALS SCIENCE; Energy Sciences; Material Science
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1417711