We show that hot carriers scattered by optic phonons in graphene undergo an anomalous parametric resonance when modulated by an ac field, at about half of the frequency ωF=2πeFvf/ωop, corresponding to ballistic acceleration up to the phonon energy ωF=2πeFvf/ωop in the presence of a dc field F. The resonance occurs in the terahertz range and is tunable with dc electric fields. Dephasing between the current and the ac field also exhibits a nonzero minimum at resonance for weak elastic scattering, while increasing monotonously with ac frequency for strong elastic scattering. The overall effect would also manifest in a long-range spatially varying periodic potential.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Apr 19 2013|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics