Magnetoresistance and magnetic breakdown in the quasi-two-dimensional conductors (BEDT-TTF)2_2MHg(SCN)4_4[M=K,Rb,Tl]

The magnetic field dependence of the resistance of (BEDT-TTF)$_2$MHg(SCN)$_4$[M=K,Rb,Tl] in the density-wave phase is explained in terms of a simple model involving magnetic breakdown and a reconstructed Fermi surface. The theory is compared to measurements in pulsed magnetic fields up to 51 T. The value implied for the scattering time is consistent with independent determinations. The energy gap associated with the density-wave phase is deduced from the magnetic breakdown field. Our results have important implications for the phase diagram.Comment: 5 pages, RevTeX + epsf, 3 figures. To appear in Physical Review B, Rapid Communications, September 15, 199

Magneto-oscillations in the high-magnetic-field state of (TMTSF)(2)ClO4

We report a systematic study of the anomalous rapid oscillation (RO) phenomena in the quasi-one-dimensional organic metal (TMTSF)(2)ClO4 in pulsed magnetic fields up to 51 T. We argue that the temperature and magnetic-field dependence of the RO amplitudes in the high-field state result from the reconstructed, nested Fermi surface topology at low temperatures in high magnetic fields. In this topology, the RO amplitudes depend on competing magnetic breakdown and Bragg reflection probabilities, along with Lifshitz-Kosevich reduction factors

Central-cell corrections for Si and S in GaAs in a strong magnetic field

The central-cell correction has been determined experimentally for the two donor impurities S and Si in GaAs. Data have been obtained for magnetic fields to 39 T, corresponding to γ~6. The observed behavior is in good agreement with theory. The analysis permits accurate evaluation of zero-field central-cell corrections, yielding 0.110 and 0.059 meV for S and Si, respectively