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Lissajous Rocking Ratchet: Realization in a Semiconductor Quantum Dot
Sergey Platonov1, Bernd Kästner2, Hans W Schumacher2
1Center for NanoScience and Fakultät für Physik, LMU-Munich, 80539 München, Germany.
Physical Review Letters
|September 19, 2015
Summary
We introduce a Lissajous rocking ratchet that breaks time-reversal symmetry (TRS) to create directed electron flow without bias. This novel quantum dot system allows precise control over current direction using modulated tunnel barriers, enabling new electronic applications.
Area of Science:
- Quantum electronics
- Condensed matter physics
- Nanotechnology
Background:
- Breaking time-reversal symmetry (TRS) without net bias can induce directed transport phenomena like ratchets.
- Quantum dots with modulated barriers are suitable systems for exploring such effects.
Purpose of the Study:
- To theoretically and experimentally introduce a Lissajous rocking ratchet.
- To demonstrate control over directed single-electron tunneling current by manipulating barrier modulations.
Main Methods:
- Utilizing a semiconductor quantum dot with periodically modulated dot-lead tunnel barriers.
- Investigating the effects of frequency and phase relations between two barrier modulations.
- Theoretical modeling and experimental realization of the ratchet effect.
Main Results:
- Demonstrated directed single-electron tunneling current by breaking TRS.
- Showcased full control over current direction via frequency and phase tuning of barrier modulations.
- Established the Lissajous rocking ratchet concept.
Conclusions:
- The Lissajous rocking ratchet offers a novel method for generating directed current in quantum systems.
- This concept is adaptable to various systems like nanoelectrical, nanoelectromechanical, and superconducting circuits.
- Potential applications include on-chip comparison of radio-frequency signals.
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