A tunable phonon-exciton Fano system in bilayer graphene.
Fano resonances are features in absorption, scattering or transport spectra resulting from the interaction of discrete and continuum states. They have been observed in a variety of systems. Here, we report a many-body Fano resonance in bilayer graphene that is continuously tunable by means of electrical gating. Discrete phonons and continuous exciton (electron-hole pair) transitions are coupled by electron-phonon interactions, yielding a new hybrid phonon-exciton excited state. It may also be possible to control the phonon-exciton coupling with an optical field. This tunable phonon-exciton system could allow novel applications such as phonon lasers.
Tang
Tsung-Ta
TT
Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA.
Zhang
Yuanbo
Y
Park
Cheol-Hwan
CH
Geng
Baisong
B
Girit
Caglar
C
Hao
Zhao
Z
Martin
Michael C
MC
Zettl
Alex
A
Crommie
Michael F
MF
Louie
Steven G
SG
Shen
Y Ron
YR
Wang
Feng
F