Graphene-enhanced, internal-magnetic-field-generated Rabi oscillations in metal-coated Si-SiO2 photoconductive detectors

TL;DR

This paper demonstrates room-temperature Rabi oscillations in silicon-based photoconductive detectors enhanced by graphene, achieved through internal magnetic fields generated by laser excitation without external magnets.

Contribution

It introduces a novel, simple, low-cost silicon device with graphene buffer that enhances Rabi oscillations via internal magnetic fields at room temperature.

Findings

Rabi oscillations at 15 MHz and 25 MHz frequencies.

Graphene buffer layer triples the oscillation amplitude.

Device operates effectively at room temperature.

Abstract

We report our demonstration of Rabi oscillations in Si-SiO2-Al photoconductive devices with nanosecond laser pulses of a few nJ at room temperature without external magnetic fields. Zeeman splitting of spin quantum states of dopants in silicon is achieved with internal magnetic fields produced by the Al film under excitation of laser pulses. Rabi oscillation frequency is 15 MHz and 25 MHz when photocurrent direction is perpendicular and parallel, respectively, to the propagation direction of linearly-polarized, 532-nm, 7-ns laser pulses. Insertion of graphene buffer layer between Al and SiO2 provides a three-fold enhancement in Rabi oscillation amplitude. This simple-structured, low-cost device operated at room temperature should open a new avenue for future spin-based electronics and optoelectronics.