Посилання:Magnetic quantum oscillations in the charge-density-wave state of the organic metals α-(BEDT-TTF)₂MHg(SCN)₄ with M = K and Tl / M.V. Kartsovnik, V.N. Zverev, D. Andres, W. Biberacher, T. Helm, P.D. Grigoriev, R. Ramazashvili, N.D. Kushch, H. Müller // Физика низких температур. — 2014. — Т. 40, № 4. — С. 484-491. — Бібліогр.: 65 назв. — англ.
Підтримка:This work has been supported by the German Research
Foundation grant KA 1652/4-1, by the Russian Foundation
for Basic Research grants Nos. 12-02-00312 and 13-02-
00178, and by SIMTECH Program grant 246937. The experiments
in fields above 15 T were supported by the
LNCMI-CNRS, member of the European Magnetic Field
Laboratory (EMFL). The visit of P.D.G. to the LPT Toulouse
was supported by l’Agence Nationale de la Recherche
under the program ANR-11-IDEX-0002-02, reference
ANR-10-LABX-0037-NEXT.
The low-temperature charge-density-wave (CDW) state in the layered organic metals α-(BEDT-TTF)₂MHg(SCN)₄
has been studied by means of the Shubnikov–de Haas and de Haas–van Alphen effects. In addition to the dominant
α-frequency, which is also observed in the normal state, both the magnetoresistance and magnetic torque possess a
slowly oscillating component. These slow oscillations provide a firm evidence for the CDW-induced reconstruction
of the original cylindrical Fermi surface. The α-oscillations of the interlayer magnetoresistance exhibit an anomalous
phase inversion in the CDW state, whereas the de Haas–van Alphen signal maintains the normal phase. We argue
that the anomaly may be attributed to the magnetic-breakdown origin of the α-oscillations in the CDW state.
A theoretical model illustrating the possibility of a phase inversion in the oscillating interlayer conductivity in the
presence of a spatially fluctuating magnetic breakdown gap is proposed.