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VOLUME 72 (2000) | ISSUE 3 |
PAGE 205
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Does the "quantized nesting model" properly describe the magnetic-field-induced spin-density-wave transitions?
Lebed A.G.
PACS: 71.70.Kn
Theoretical reinvestigation of a so-called field-induced spin-density-wave (FISDW) phase diagram in a magnetic field in quasi-one-dimensional compounds (TMTSF)jX (X=PFe, СЮ4, AsFe, etc.) has revealed some novel qualitative features. Among them, axe: 1) the FISDW wave vector is never strictly quantized; 2) the FISDW phase diagram consists of two regions: a) "Quantum FISDW", where there exist jumps of the FISDW wave vectors between different FISDW-subphases, b) "Quasiclassical FISDW", where the jumps disappear above some critical points and only one FISDW phase (characterizing by a wave vector oscillating with a magnetic field) exists. Both these features are due to taking account of a breaking of an electron-hole symmetry. They contradict to the previous text-book theoretical results (including the calculations of the "Three Dimensional Quantum Hall Effect") performed by means of the "Quantized Nesting Model" which explicitly assumes the existence of the electron-hole symmetry. We stress that some effects related to the phenomena described above were experimentally observed but were not properly interpreted.
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