Nanowerk September 15, 2021
An international team of researchers (Germany, Spain, USA – the Flatiron Institute) predicted that a unique laser source could produce highly controllable electric currents in any bulk material. They focused on an intense laser beam comprised of only low-energy photons, which incorporates two circularly-polarized carrier frequencies. The polarization of the electromagnetic field of this beam plots a distinct shape in space and time. The combination of the two colors leads to a double-loop motion that pushes electrons in the solid in various directions. Together with the intense beam, the double-loop laser light produces many photons which are simultaneously absorbed, exciting the electrons to produce a current with little heating in the material. This makes a highly efficient conversion process with its direction and amplitude highly controllable as the photocurrent always emerges at a 90-degree angle to the laser. According to the researchers with their approach, photocurrents can be generated in a wide range of two- and three-dimensional materials, from diamond and silicon to graphene and other semi-metals…read more. Open Access TECHNICAL ARTICLEÂ
Bulk photocurrent generation in diamond by THz cocircular ω−2 fields…Credit: Phys. Rev. Lett. 127, 126601, 13 September 2021Â