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arXiv · 1612.07302

Nuclear magnetic resonance and nuclear spin relaxation in AlAs quantum well probed by ESR

A. V. Shchepetilnikov·D. D. Frolov·Yu. A. Nefyodov·I. V. Kukushkin·D. S. Smirnov·L. Tiemann·C. Reichl·W. Dietsche·W. Wegscheider
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Abstract

The study of nuclear magnetic resonance and nuclear spin-lattice relaxation was conducted in an asymmetrically doped to $n\sim1.8\times10^{11}$ cm$^{-2}$ 16 nm AlAs quantum well grown in the $[001]$-direction. Dynamic polarization of nuclear spins due to the hyperfine interaction resulted in the so-called Overhauser shift of the two-dimensional conduction electron spin resonance. The maximum shifts achieved in the experiments are several orders of magnitude smaller than in GaAs-based heterostructures indicating that hyperfine interaction is weak. The nuclear spin-lattice relaxation time extracted from the decay of Overhauser shift over time turned out to depend on the filling factor of the two-dimensional electron system. This observation indicates that nuclear spin-lattice relaxation is mostly due to the interaction between electron and nuclear spins. Overhauser shift diminishes resonantly when the RF-radiation of certain frequencies was applied to the sample. This effect served as an indirect, yet powerful method for nuclear magnetic resonance detection: NMR quadrupole splitting of $^{75}$As nuclei was clearly resolved. Theoretical calculations performed describe well these experimental findings.

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A. V. Shchepetilnikov, D. D. Frolov, Yu. A. Nefyodov, I. V. Kukushkin, D. S. Smirnov, L. Tiemann, C. Reichl, W. Dietsche, W. Wegscheider. 2016-12-21. Nuclear magnetic resonance and nuclear spin relaxation in AlAs quantum well probed by ESR. https://doi.org/10.1103/physrevb.94.241302

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