1999 Fiscal Year Final Research Report Summary
Theory of micro-wave absorption of 2-dimensional Wigner crystals
| Project/Area Number |
10640307
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
固体物性Ⅰ(光物性・半導体・誘電体)
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| Research Institution | Osaka University |
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Principal Investigator |
SAITOH Motohiko Graduate School of Science, Osaka University Professor, 大学院・理学研究科, 教授 (80012441)
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| Project Period (FY) |
1998 – 1999
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| Keywords | Wigner crystals / two-dimensional electrons / plasma resonance / micro-wave absorption / ripplons / liquid helium surface |
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| Research Abstract |
1.It is pointed out that 2-dimensional electrons located at the interface of semiconductor hetero-structures such as Si-MOS experience the localized-delocalized transition by the influence of impurities in oxides. We have shown by using the path-integral formalism that when electrons form an electron crystal or Wigner lattice, the Wigner phonon spectra have an energy gap in the long wave-length limit, and that the electrons are localized. The line-shape of the micro-wave absorption is not of the Lorentzian type but asymmetric owing to the density of states of the Wigner phonons.
2.Kono et al. measured the plasmon resonance of quasi-2-dimensional electrons on liquid helium 3 at very low temperatures and found that (a) the resonance position is almost independent of temperature, and (b) the line-width is roughly proportional to temperature. By assuming that the 2-dimensional electrons form a Wigner crystal which interacts with the surface capillary waves or ripplons of liquid helium, we have calculated the line-width of the plasmon resonance by the linear ac conductivity formula obtained by the path-integral method. The results show that the line-width is proportional to temperature and is in good agreement with experiments. This temperature dependence comes from the number of scatterers, i. e., of thermally excited ripplons.
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Research Products
(4 results)
