Photocurrents induced by structured light

Advances in manipulating the structure of optical beams enable the study of interaction between structured light and low-dimensional semiconductor systems. We explore the photocurrents in two-dimensional systems excited by such inhomogeneous radiation with structured field. Besides the contribition associated with the intensity gradient, the photocurrent contains contributions driven by the gradients of the Stokes polarization parameters and the phase of the electromagnetic field. We develop a microscopic theory of the photocurrents induced by structured light and derive analytical expressions for all the photocurrent contributions at intraband transport of electrons. The theory is applied to analyze the radial and azimuthal photocurrents excited by twisted light beams carrying orbital angular momentum, and possible experiments to detect the photocurrents are discussed.