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Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
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Defect-mediated spin relaxation and dephasing in graphene.
M B Lundeberg1, R Yang1, J Renard1
1Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T1Z4.
Physical Review Letters
|August 29, 2014
Summary
Magnetic defects, not spin-orbit interaction, cause rapid spin relaxation in graphene, hindering quantum spintronics. This quantum interference study identifies magnetic impurities as the main decoherence source in graphene spin transport.
Area of Science:
- Quantum physics
- Materials science
- Condensed matter physics
Background:
- Graphene is a promising material for quantum spintronics due to expected negligible hyperfine and spin-orbit interactions.
- Experimental spin transport in graphene reveals spin relaxation rates significantly faster than theoretical predictions.
Purpose of the Study:
- To investigate the primary sources of spin decoherence in graphene.
- To differentiate between magnetic and nonmagnetic contributions to spin relaxation.
- To clarify the role of spin-orbit interaction in graphene's spin dynamics.
Main Methods:
- Utilized quantum interference measurements.
- Developed techniques to disentangle magnetic and nonmagnetic decoherence sources.
- Performed spin transport experiments in single-layer graphene.
Main Results:
- Identified magnetic defects as the dominant cause of spin relaxation in graphene.
- Demonstrated that magnetic impurities mask the potential effects of spin-orbit interaction.
- Quantified the contribution of magnetic decoherence to spin relaxation.
Conclusions:
- Magnetic defects are the primary limitation for spin coherence in graphene, not intrinsic spin-orbit interactions.
- Understanding and mitigating magnetic impurities is crucial for realizing graphene's potential in quantum spintronics.
- Future research should focus on defect control and reduction in graphene fabrication.
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