Recently, a research team from the Shanghai Institute of Optics and Fine Mechanics at the Chinese Academy of Sciences has made a significant theoretical leap in harnessing ultrafast light fields to control petahertz (PHz) photocurrents in two-dimensional material devices. As conventional semiconductor technology nears its physical boundaries, the burgeoning field of "optoelectronics" has stepped into the limelight. This field capitalizes on the power of ultra-intense and ultrafast lasers to precisely direct electron movement, paving the way for signal processing speeds to soar into the PHz realm.

Previous research endeavors have predominantly relied on the "single-particle picture," overlooking the crucial interplay between electrons. To bridge this knowledge gap, the research team turned to a nonequilibrium Green's function theoretical framework. This approach allowed them to simulate how the complex, many-body interactions among electrons, when subjected to intense laser driving, influence their ultrafast dynamics.

The study uncovered that photocurrents, predominantly shaped by many-body effects, ignite electron interactions. These interactions, in turn, lead to a renormalization of the material's band structure and trigger interference phenomena during the generation of photoelectrons. Furthermore, the team ingeniously introduced two laser pulses with orthogonal polarizations. This innovation enabled them to separate the "injection" and "control" processes of photocurrent, achieving an ultra-high-speed current modulation frequency that nears 1 PHz.

Leveraging this groundbreaking approach, the team proposed a conceptual blueprint for constructing PHz optoelectronic logic gates. They also charted a new technological course for measuring electron decoherence times. This research marks a pivotal transition in optoelectronics, propelling it from the "single-particle picture" to a new era defined by "many-body correlations." It lays down essential theoretical groundwork and offers innovative technological avenues for designing cutting-edge, ultrafast, and low-power optoelectronic devices. The relevant findings have been published in Physical Review B.