Light-Driven Ultrafast Electric Gating

Patent Status

Brief Description

The inventors have successfully applied this method to a quantum well Rashba system, as this is considered today one of the most promising candidates for spin-based devices, such as the Datta Das spin-transistor. The technology can induce an ultrafast gate and drive time-dependent Rashba and quantum well dynamics never observed before, with switching faster than 10GHz. This approach minimizes lithography and will enable light-driven electronic and spintronics devices such as transistors, spin-transistors, and photo-controlled Rashba circuitry. This method can be applied with minimal effort to any two-dimensional material, for both exfoliated and molecular beam epitaxy grown samples.

Suggested uses

Examples of device applications include:

• photo-transistors
• spin-transistors/spin-current filters (the inventor prototype demonstrated ultrafast gate controlled Rashba splitting)
• photodetection
• solar cells

Advantages

In contrast, the new method removes the need for a lithographed backgate. The gate is the substrate material itself, in which many semiconductor materials already used in typical semiconductor processing can serve as suitable SPV substrate candidates. Since the gate is operated with focused laser light, the geometry, location, and timing of the gating region is flexible, allowing for complex operations across an integrated wafer without intricate arrangements of gating structures. Moreover, the light-driven aspect of the gating method enables novel device creation for applications that combine photonic and electronic processes.

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