Coherent Photocurrent Injection through Quantum Interference between Stimulated Electronic Raman Scattering and Single-Photon Absorption in Intrinsic Graphene

The physical picture for photocurrent injection and coherent control in intrinsic graphene under two-color laser excitation remains obscure. Previously, photocurrent injection of intrinsic graphene was attributed to the quantum interference between two electronic transition pathways of single-photon and two-photon absorptions as well as layer-to-layer coupling. Here, we show that quantum interference between stimulated electronic Raman scattering and single-photon absorption plays a very important role in contributing to the total photocurrent, while interlayer coupling does not sufficiently affect the photocurrent injection, which is in contrast to the previous interpretation of the experimental results on photocurrent injection and coherent control. Our findings may change the basic understanding of the physical picture of electron transitions and photocurrent injection, which may benefit the design and fabrication of graphene-based optoelectronic devices.