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Updated: Apr 18, 2026

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
Quantum ratchet in two-dimensional semiconductors with Rashba spin-orbit interaction
Yee Sin Ang1, Zhongshui Ma2, Chao Zhang3
1School of Physics, University of Wollongong, New South Wales 2522, Australia.
Researchers developed a quantum ratchet using asymmetrical quantum tunneling in a two-dimensional electron gas. This device generates a direct electron current from an alternating force without external magnetic fields or symmetry breaking.
Area of Science:
- Quantum physics
- Condensed matter physics
- Spintronics
Background:
- Ratchet mechanisms convert random motion into directed motion.
- Quantum effects can be harnessed for novel electronic devices.
- Rashba spin-orbit interaction influences electron behavior in confined systems.
Purpose of the Study:
- To demonstrate a simple scattering quantum ratchet.
- To utilize asymmetrical quantum tunneling for current generation.
- To investigate electron transport in two-dimensional electron gas (2DEG) with Rashba spin-orbit interaction (R2DEG).
Main Methods:
- Simulating electron tunneling across an asymmetrical potential barrier.
- Incorporating interface scattering potentials of unequal strengths.
- Analyzing intra-spin and inter-spin-subband tunneling probabilities.
Main Results:
- Observed unequal inter-spin-subband tunneling probabilities for opposite directions.
- Demonstrated directional electron flow when driven by a periodic force.
- Achieved rectification of an alternating current (a.c.) driving force.
Conclusions:
- A scattering quantum ratchet in R2DEG is feasible and conceptually simple.
- The device converts a.c. driving force into a rectified current.
- No additional symmetry breaking or external magnetic field is required.
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