Shift Current Response in Twisted Multilayer Graphene
ORAL
Abstract
Twisted bilayer graphene (TBG) has shown to be an excellent material for photovoltaic applications in the terahertz range due to its nontrivial band topology of flat bands. In twisted multilayer graphene (TMG), we observe the presence of multiple flat bands hybridizing with each other through a self-generated displacement field. We investigate the role of these additional flat bands in TMG in enhancing the shift current response. Our numerical calculation indicates that the additional transitions among different flat bands and to the dispersive Dirac cone led to an overall enhancement of shift current response. A new peak in shift current conductivity occurs at a wide range of fillings at frequency determined by the mean energy of the two bands near K and K’ points. In addition, we explore the connection between charge inhomogeneity in the moiré unit cell and the magnitude of shift current response.
–
Presenters
-
Sihan Chen
Caltech
Authors
-
Sihan Chen
Caltech
-
Cyprian K Lewandowski
Florida State University
-
Swati Chaudhary
Northeastern University, University at Texas at Austin, Caltech, The University of Texas at Austin, Northeastern University, Massachusetts Institute of Technology, University of Texas at Austin, The university of Texas at Austin
-
Gil Refael
Caltech