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Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping
Published on: June 3, 2015
Resonance energy and charge pumping through quantum SINIS contacts
N B Kopnin1, A S Mel'nikov, V M Vinokur
1Low Temperature Laboratory, Helsinki University of Technology, P.O. Box 2200, FIN-02015 HUT, Finland.
Physical Review Letters
|May 23, 2006
Summary
We discovered quantum pumping in a superconductor junction, driven by spectral flow and minigap changes. This process generates large direct current peaks at specific rational voltages.
Area of Science:
- Condensed matter physics
- Quantum phenomena
- Superconductivity
Background:
- Quantum pumping enables controlled charge transport without external gates.
- Superconductor/insulator/normal-metal/insulator/superconductor (SINIS) junctions are crucial for studying quantum effects.
Purpose of the Study:
- To propose and investigate a novel quantum pumping mechanism in a voltage-biased SINIS junction.
- To explore the role of spectral flow and minigap dynamics in quantum pumping.
Main Methods:
- Theoretical modeling of quantum pumping in a SINIS junction.
- Analysis of spectral flow and minigap evolution with applied voltage.
- Investigating the relationship between Josephson frequency and energy spectrum.
Main Results:
- A quantum pumping mechanism mediated by spectral flow is proposed.
- The sequential closing of minigaps in the energy spectrum drives the pumping.
- Giant peaks in the pumped direct current are observed at rational voltages.
Conclusions:
- The proposed mechanism offers a new route for generating quantized charge transport.
- The observed giant peaks at rational voltages provide experimental signatures for this pumping mechanism.
- This work advances the understanding of quantum transport in hybrid superconducting systems.
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