Magnetic Splitting of the Zero Bias Peak in a Quantum Point Contact with a Variable Aspect Ratio
| Autor: | Steven Herbert, Michael R. Melloch, Andrei Kogan, Tai-Min Liu, Bryan Hemingway |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Physics
Condensed Matter - Mesoscale and Nanoscale Physics Condensed matter physics Quantum point contact Coulomb blockade FOS: Physical sciences Heterojunction Zero field splitting Condensed Matter Physics Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 01 natural sciences 010305 fluids & plasmas Electronic Optical and Magnetic Materials Quantum dot 0103 physical sciences Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Zeeman energy Kondo effect 010306 general physics Fermi gas |
| DOI: | 10.48550/arxiv.0910.0570 |
| Popis: | We report a zero-bias peak in the differential conductance of a Quantum Point Contact (QPC), which splits in an external magnetic field. The peak is observed over a range of device conductance values starting significantly below $2e^2/h$. The observed splitting closely matches the Zeeman energy and shows very little dependence on gate voltage, suggesting that the mechanism responsible for the formation of the peak involves electron spin. Precision Zeeman energy data for the experiment are obtained from a separately patterned single-electron transistor located a short distance away from the QPC. The QPC device has four gates arranged in a way that permits tuning of the longitudinal potential, and is fabricated in a GaAs/AlGaAs heterostructure containing 2-dimenional electron gas. We show that the agreement between the peak splitting and the Zeeman energy is robust with respect to moderate distortions of the QPC potential. We also show that the mechanism that leads to the formation of the ZBP is different from the conventional Kondo effect found in quantum dots. Comment: 10 pages, 6 figures |
| Databáze: | OpenAIRE |
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