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Spin-dependent quasiparticle transport in aluminum single-electron transistors
A J Ferguson1, S E Andresen, R Brenner
1Australian Research Centre of Excellence for Quantum Computer Technology, University of New South Wales, Sydney NSW 2052, Australia. andrew.ferguson@unsw.edu.au
Physical Review Letters
|October 10, 2006
Summary
Zeeman splitting influences quasiparticle transport in normal-superconducting-normal aluminum single-electron transistors. This effect enables control over spin-dependent tunneling, suggesting potential for bipolar spin filter applications.
Area of Science:
- Condensed Matter Physics
- Quantum Transport
Background:
- Normal-superconducting-normal (NSN) junctions are crucial for studying quantum phenomena.
- Zeeman splitting, the energy shift of spin states in a magnetic field, impacts electronic behavior.
Purpose of the Study:
- To investigate the influence of Zeeman splitting on quasiparticle transport in aluminum single-electron transistors (SETs).
- To explore the spin-dependence of tunneling in NSN devices under the effect of Zeeman splitting.
Main Methods:
- Fabrication and characterization of aluminum single-electron transistors (SETs).
- Measurement of quasiparticle transport through the SETs under varying magnetic fields (to induce Zeeman splitting).
- Analysis of tunneling currents considering Coulomb blockade and spin effects.
Main Results:
- Zeeman splitting was found to induce spin-dependence in sequential tunneling processes.
- Specific transport regimes were identified where only one or both spin species could tunnel.
- Spin-dependence of single quasiparticle states was observed at lower bias voltages.
Conclusions:
- The interplay of Coulomb blockade and Zeeman splitting offers control over spin-dependent transport in NSN SETs.
- The observed spin-dependent tunneling phenomena suggest the potential for developing bipolar spin filters.
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