Trionic optical potential for electrons in semiconductors

Laser-induced optical potentials for atoms have led to remarkable advances in precision measurement, quantum information and towards addressing fundamental questions in condensed-matter physics. Here, we describe analogous optical potentials for electrons in quantum wells and wires that can be generated by optically driving the transition between a single electron and a three-body electron–exciton bound state, known as a trion. The existence of a bound trion state adds a term to the a.c. Stark shift of the material proportional to the light intensity at the position of the electron. According to our theoretical calculations, this shift can be large relative to the thermal equilibrium temperature of the electron, resulting in a relatively strong optical potential that could be used to trap, guide and manipulate individual electrons within a semiconductor quantum well or wire. These potentials can be thought of as artificial nanostructures on the scale of 100 nm that can be spin dependent and reconfigurable in real time. Our results suggest the possibility of integrating ultrafast optics and gate voltages in new resolved-carrier semiconductor optoelectronic devices, with potential applications in fields such as nanoelectronics, spintronics and quantum information processing.