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Ultraslow Electron Spin Dynamics in GaAs Quantum Wells Probed by Optically Pumped NMR

N. N. Kuzma·P. Khandelwal·S. E. Barrett·L. N. Pfeiffer·K. W. West
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Abstract

Optically pumped nuclear magnetic resonance (OPNMR) measurements were performed in two different electron-doped multiple quantum well samples near the fractional quantum Hall effect ground state nu=1/3. Below 0.5K, the spectra provide evidence that spin-reversed charged excitations of the nu=1/3 ground state are localized over the NMR time scale of ~40 microseconds. Furthermore, by varying NMR pulse parameters, the electron spin temperature (as measured by the Knight shift) could be driven above the lattice temperature, which shows that the value of the electron spin-lattice relaxation time lies between 100 microseconds and 500 milliseconds at nu=1/3.

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N. N. Kuzma, P. Khandelwal, S. E. Barrett, L. N. Pfeiffer, K. W. West. 1999-07-20. Ultraslow Electron Spin Dynamics in GaAs Quantum Wells Probed by Optically Pumped NMR. https://doi.org/10.1126/science.281.5377.686

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