Ultrafast valley polarization in bilayer graphene
Abstract
We study theoretically the interaction of a bilayer graphene with a circularly polarized ultrafast optical pulse of a single oscillation at an oblique incidence. The normal component of the pulse breaks the inversion symmetry of the system and opens up a dynamical bandgap due to which a valley-selective population of the conduction band becomes sensitive to the angle of incident of the pulse. We show that the magnitude of the valley polarization can be controlled by the angle of incidence, the amplitude, and the angle of in-plane polarization of the chiral optical pulse. Subsequently, a sequence of a circularly polarized pulse followed by a linearly polarized femtosecond-long pulse can be used to control and probe the valley polarization created by the preceding pulse. Our protocol provides a favorable platform to design ultrafast all-optical valleytronic information processing.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 27, 2021
- Source ID
- 10.1063/5.0060138
Entities
People
- Pardeep Kumar
- Thakshila M. Herath
- Vadym Apalkov
Organizations
- Air Force Office of Scientific Research
- Georgia State University
- Max Planck Institute for the Science of Light
- National Science Foundation
- Office of Naval Research
- United States Department of Energy