Magnetic quantum oscillations in the charge-density-wave state of the organic metals $\alpha$-(BEDT-TTF)${}_2$MHg(SCN)${}_4$ with M = K and Tl

Abstract

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 alpha-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.

19 pages, 4 figures; submitted to Low Temperature Physics, special issue "New Trends of Fermiology" dedicated to the 60-th anniversary of the Lifshitz-Kosevich theory

References in corpus (2)

• Quasiparticle mass enhancement close to the quantum critical point in BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• Longitudinal interlayer magnetoresistance in quasi-2D metals

Cited by in corpus (3)

• Linear magnetoresistance in the charge density wave state of quasi-two-dimensional rare-earth tritellurides
• Enhancements of the 3/2 and 5/2 frequencies of de Haas-van Alphen oscillations near the Lifshitz transition in the two-dimensional compensated metal with overtilted Dirac cones
• Charge-localization-driven metal-insulator phase transition in layered molecular conductors