- Tytuł:
- Investigations of Fermi Surfaces and Effective Masses of the Organic Superconductors (BEDO-TTF)$\text{}_{2}$ReO$\text{}_{4}$(H$\text{}_{2}$O) and κ-(BEDT-TTF)$\text{}_{2}$I$\text{}_{3}$ by Shubnikov-de Haas and de Haas-van Alphen Measurements
- Autorzy:
-
Schweitzer, D.
Balthes, E.
Karlich, S.
Heinen, I.
Keller, H.
Strunz, W.
Biberacher, W.
Jansen, A.G.M.
Steep, E. - Powiązania:
- https://bibliotekanauki.pl/articles/1933332.pdf
- Data publikacji:
- 1995-04
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
71.25.Jd
71.25.Hc
74.70.Kn - Opis:
- The Fermi surfaces and effective masses of (BEDO-TTF)$\text{}_{2}$ReO$\text{}_{4}$(H$\text{}_{2}$0) and κ-(BEDT-TTF)$\text{}_{2}$I$\text{}_{3}$ were investigated by Shubnikov–de Haas (SdH) and de Haas–van Alphen (dHvA) measurements in magnetic fields up to 27 T in the temperature range from 0.5 K to 4.2 K. Two small closed pockets (0.7% and 1.5% of the first Brillouin zone) are observed in (BEDO-TTF)$\text{}_{2}$ReO$\text{}_{4}$(H$\text{}_{2}$0) corresponding very well with two cross-sectional areas of the Fermi surfaces obtained for a hole and an electron pocket from tight binding calculations. In contrast, in κ-(BEDT-TTF)$\text{}_{2}$I$\text{}_{3}$ two relatively large closed sections (13% and 85% of the first Brillouin zone) of the Fermi surfaces are observed, again confirming the tight binding calculations. For κ-(BEDT-TTF)$\text{}_{2}$I$\text{}_{3}$ in magnetic fields above 12 T the effective mass for the larger orbit, as obtained from the temperature dependence of the SdH-oscillation amplitudes, is magnetic field dependent as long as the field is arranged perpendicular to the conducting planes (Θ = 0°). In contrast, from dHvA measurements - which were performed by turning the magnetic field by 27° with respect to the SdH experiments - the observed effective mass is field independent. We suppose that the occurrence of anyons at temperatures below 1 K and in fields above 12 T might be the reason for the observed field dependence of the effective mass in the SdH investigations under the special angle 0°.
- Źródło:
-
Acta Physica Polonica A; 1995, 87, 4-5; 749-759
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
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