Photogalvanic effects in heteropolar nanotubes
We show that an electrical shift current is generated when electrons are photoexcited from the valence to conduction bands on a BN nanotube. This photocurrent follows the light pulse envelope and its symmetry is controlled by the atomic structure of the nanotube. We find that the shift current has an intrinsic quantum mechanical signature in which the chiral index of the tube determines the direction of the current along the tube axis. We identify the discrete lattice effects in the tangent plane of the tube that lead to an azimuthal component of the shift current. The nanotube shift current can lead to ultrafast optoelectronic and optomechanical applications.
Kral
P
Department of Chemical Physics, Weizmann Institute of Science, 76100 Rehovot, Israel.
Mele
EJ
Tomanek
D