Magnetic quantum oscillations in the charge-density-wave state of the organic metals alpha-(BEDT-TTF())2MHg(SCN)(4) with M=K and Tl

作者：Kartsovnik M V^*; Zverev V N; Andres D; Biberacher W; Helm T; Grigoriev P D; Ramazashvili R; Kushch N D; Mueller H

来源：Low Temperature Physics, 2014, 40(4): 377-383.

DOI：10.1063/1.4869592

The low-temperature charge-density-wave (CDW) state in the layered organic metals alpha-(BEDT-TTF)(2)MHg(SCN)(4) has been studied by means of the Shubnikov-de Haas and de Haas-van Alphen effects. In addition to the dominant a-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 alpha-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 alpha-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.

• 出版日期2014-4