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Measuring the Spin-Lattice Relaxation Magnetic Field Dependence of Hyperpolarized [1-13C]pyruvate
Published on: September 13, 2019
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Ultralong 100 ns spin relaxation time in graphite at room temperature
B G Márkus1,2,3, M Gmitra4,5, B Dóra6
1Stavropoulos Center for Complex Quantum Matter, Department of Physics and Astronomy, University of Notre Dame, Notre Dame, IN, 46556, USA.
Nature Communications
|May 17, 2023
Summary
Electron spin dynamics in graphite were studied. Researchers found significantly longer spin lifetimes (T1) than expected, suggesting graphite is a promising material for spintronics applications.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Electron spin dynamics in graphite remain poorly understood despite decades of research.
- Previous assumptions suggested longitudinal (T1) and transverse (T2) relaxation times are equal in graphite, but T1 has never been experimentally measured.
Purpose of the Study:
- To investigate the unresolved problem of electron spin dynamics in graphite.
- To measure the longitudinal (T1) and transverse (T2) relaxation times and compare them.
- To explore the potential of graphite for spintronics applications.
Main Methods:
- Detailed band structure calculations incorporating spin-orbit coupling.
- Saturation Electron Spin Resonance (ESR) measurements.
- Density Functional Theory (DFT) calculations to analyze spin admixture.
Main Results:
- A significant difference between T1 and T2 relaxation times was observed, contradicting previous assumptions.
- Spins with perpendicular polarization exhibit an exceptionally long lifetime of 100 ns at room temperature, ten times longer than in optimal graphene.
- An ultralong spin diffusion length of approximately 70 μm across graphite planes is predicted.
Conclusions:
- Graphite demonstrates unexpected electron spin behavior with potential for advanced spintronics.
- Thin graphite films and multilayer AB graphene stacks are identified as excellent platforms for 2D van der Waals compatible spintronics.
- Anisotropic spin admixture in graphite Bloch states provides a qualitative explanation for the observed spin relaxation.
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