APPLICATIONS OF TECHNOLOGY:
- Method to explore and test material properties under ultrafast external fields
- Light-driven novel device applications that combine photonic and electronic processes (e.g., photo-transistors and spin-transistors)
- Minimizes lithography
- Enables complex operations across an integrated wafer without intricate arrangements of gating structures
- Applicable to any two-dimensional material with minimal effort (i.e. both exfoliated and molecular beam epitaxy grown samples)
- Electric field gating is one of the most fundamental tuning knobs for all modern solid-state technology and is the foundation of many solid-state devices such as transistors. However, current methods for in-situ back-gated devices are difficult to fabricate, introduce unwanted contaminants, and are unsuited for picosecond time-resolved electric field studies.
Researchers at Berkeley Lab have invented a novel way to generate ultrafast back-gating by leveraging the surface band bending inherent to many semiconductor materials.
The architecture includes a standard bulk semiconductor material and a layered material on the surface. Researchers have successfully applied this method to a quantum well Rashba system, which is currently considered to be one of the most promising candidates for spin-based devices (e.g., Datta Das spin-transistor). They have demonstrated that they can induce an ultrafast gate and drive time-dependent Rashba and quantum well dynamics never observed before, with switching faster than 10 GHz. As a result, it is very simple to trigger measurements and device outputs to the output of the light source, enabling ultrafast gating experiments as well as precision device synchronization.
This development establishes the ultrafast gate as a viable approach for creating novel quantum well and spintronic devices.
DEVELOPMENT STAGE: Proven principle
STATUS: Patent pending.
OPPORTUNITIES: Available for licensing or collaborative research.