Optically Pumped Nuclear Magnetic Resonance Measurements of the Electron Spin Polarization in GaAs Quantum Wells near Landau Level Filling Factorν=13
| Autor: | Ken W. West, P. Khandelwal, L. N. Pfeiffer, S. E. Barrett, N. N. Kuzma |
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| Rok vydání: | 1998 |
| Předmět: |
Physics
Condensed matter physics Filling factor General Physics and Astronomy Knight shift 02 engineering and technology Landau quantization Quantum Hall effect Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology Polarization (waves) 01 natural sciences Nuclear magnetic resonance Quantum spin Hall effect 0103 physical sciences Quasiparticle Condensed Matter::Strongly Correlated Electrons 010306 general physics 0210 nano-technology Quantum well |
| Zdroj: | Physical Review Letters. 81:673-676 |
| ISSN: | 1079-7114 0031-9007 |
| DOI: | 10.1103/physrevlett.81.673 |
| Popis: | The Knight shift of Ga-71 nuclei is measured in two different electron-doped multiple quantum well samples using optically pumped NMR. These data are the first direct measurements of the electron spin polarization, P(nu,T)= /max , near nu=1/3. The P(T) data at nu=1/3 probe the neutral spin-flip excitations of a fractional quantum Hall ferromagnet. In addition, the saturated P(nu) drops on either side of nu=1/3, even in a Btot=12 Tesla field. The observed depolarization is quite small, consistent with an average of about 0.1 spin-flips per quasihole (or quasiparticle), a value which does not appear to be explicable by the current theoretical understanding of the FQHE near nu=1/3. |
| Databáze: | OpenAIRE |
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