Angle-dependent magnetoresistance oscillations and charge density wave in the organic conductor α-(BEDT-TTF)2KHg(SCN)4

Abstract

We have performed full stereographic study on angle-dependent magnetoresistance oscillations (AMROs) in the layered organic conductor, α-(BEDT-TTF)2KHg(SCN)4, which shows a charge density wave (CDW) transition at Tc. AMROs originating from normal Fermi surfaces (FSs) and reconstructed ones appear above Tc and much below Tc, respectively. We have observed mixing of these AMROs just below Tc in the CDW phase. Observed features strongly suggest magnetic breakdown in reconstructed FSs. In fact, they are reproduced by a quantum-mechanical model on AMROs under weak periodic potential. The possibility of the unconventional CDW, in which the CDW gap has nodal points on the Fermi surface, is excluded in this compound. © 2013 The Physical Society of Japan.