Volume 85, Number 4, February 2009
Article Number 47001
Number of page(s) 5
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 16 February 2009
EPL, 85 (2009) 47001
DOI: 10.1209/0295-5075/85/47001

Theory of the optical absorption of light carrying orbital angular momentum by semiconductors

G. F. Quinteiro and P. I. Tamborenea

Departamento de Física “J. J. Giambiagi”, Universidad de Buenos Aires - Ciudad Universitaria, Pabellón I, C1428EGA, Ciudad de Buenos Aires, Argentina

received 20 November 2008; accepted in final form 25 January 2009; published February 2009
published online 16 February 2009

We develop a free-carrier theory of the optical absorption of light carrying orbital angular momentum (twisted light) by bulk semiconductors. We obtain the optical transition matrix elements for Bessel-mode twisted light and use them to calculate the wave function of photo-excited electrons to first-order in the vector potential of the laser. The associated net electric currents of first and second-order on the field are obtained. It is shown that the magnetic field produced at the center of the beam for the $\ell$ = 1 mode is of the order of a millitesla, and could therefore be detected experimentally using, for example, the technique of time-resolved Faraday rotation.

78.20.Bh - Theory, models, and numerical simulation.
78.20.Ls - Magnetooptical effects.
78.40.Fy - Semiconductors.

© EPLA 2009