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All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
Tunneling in double barrier junctions with "hot spots".
D Herranz1, F G Aliev, C Tiusan
1Departamento Física Materia Condensada, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
Physical Review Letters
|September 28, 2010
Summary
We observed quantum well states in magnetic tunnel junctions with soft breakdown. These states cause resistance oscillations at room temperature, explained by a novel tunneling model.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Spintronics
Background:
- Epitaxial Fe/MgO/Fe/MgO/Fe double magnetic tunnel junctions are crucial for spintronic devices.
- Soft barrier breakdown, or 'hot spots,' in MgO layers affects device performance.
- Nitrogen doping and continuous middle Fe layers offer unique junction properties.
Purpose of the Study:
- Investigate electronic transport in novel Fe/MgO/Fe/MgO/Fe junctions.
- Analyze the impact of soft breakdown (hot spots) on transport properties.
- Understand the formation of quantum well states under specific junction conditions.
Main Methods:
- Fabrication of epitaxial Fe(100)/MgO/Fe/MgO/Fe double magnetic tunnel junctions.
- Utilized nitrogen doping in MgO barriers to achieve soft breakdown around 0.5 V.
- Measured resistance as a function of bias voltage at room temperature.
Main Results:
- Observed quasiperiodic resistance oscillations as a function of bias voltage in junctions with hot spots.
- Attributed oscillations to the formation of quantum well states in the continuous middle Fe layer.
- Confirmed room-temperature oscillations in both parallel and antiparallel magnetic configurations and for both bias polarizations.
Conclusions:
- A simple model of tunneling through hot spots qualitatively explains the observed quantum phenomena.
- The findings provide insights into the electronic transport mechanisms in complex magnetic tunnel junctions.
- This research contributes to the understanding and design of advanced spintronic devices.
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