Light-induced quantum tunnelling current in graphene

TL;DR

This paper demonstrates ultrafast, light-induced quantum tunnelling currents in graphene phototransistors, enabling petahertz-speed switching and logic operations under ambient conditions, advancing ultrafast optoelectronic device technology.

Contribution

It reports the first observation of light-induced quantum tunnelling in graphene, achieving sub-femtosecond switching and logic gate implementation at room temperature.

Findings

Achieved 630 attosecond current switching in graphene.

Controlled tunnelling current via laser power modulation.

Demonstrated logic gates using light-induced tunnelling.

Abstract

In the last decade, advancements in attosecond spectroscopy have allowed us to study electron motion dynamics in condensed matter. The access to these electron dynamics and, consequently, its control by an ultrafast light field paves the way for establishing ultrafast optoelectronics. Here, we report the generation of light-induced quantum tunnelling current in graphene phototransistors by ultrafast laser pulses in an ambient environment. This tunnelling effect provides access to the instantaneous field-driven current to demonstrate the current switching (ON and OFF) on a 630 attosecond (1.6 petahertz speed). Moreover, we controlled the tunnelling current and enhanced the graphene phototransistor conductivity by controlling the density of the photoexcited charge carriers at different pump laser powers. Furthermore, we exploited this capability to demonstrate various logic gates. The demonstrated light-induced tunnelling current and ultrafast switching were attained under standard room temperature and pressure conditions. Therefore, the presented scientific advancement in this work is at the technology readiness level suitable for its immediate integration into the development of ultrafast, nearly six orders of magnitude faster, optical transistors, lightwave electronics, and optical quantum computers.