Aperiodic quantum oscillations of particle-hole asymmetric Dirac cones

Abstract

We report experimental measurements and theoretical analysis of Shubnikov-de Haas (SdH) oscillations in a Dirac cone system: the a-(BEDT-TTF)2I3 organic metal under hydrostatic pressure. The measured SdH oscillations reveal anomalies at high magnetic fields B where the 1/B oscillations periodicity is lost above 7 T. We interpret these unusual results within a theoretical model that takes into account intrinsic distortions of the a-(BEDT-TTF)2I3 Dirac cones such as a parabolic particle-hole asymmetric correction. Others possible causes, such as a cone tilting or a Zeeman effect, are carefully ruled out. The observations are consistent among a-(BEDT-TTF)2I3 samples with different Fermi levels.

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Cited by in corpus (3)

• De Haas-van Alphen oscillations near the Lifshitz transition from two electron pockets to one electron pocket in the two-dimensional Dirac fermion systems
• Unconventional quantum oscillations and evidence of nonparabolic electronic states in quasi-two-dimensional electron system at complex oxide interfaces
• Anomalous Landau levels and quantum oscillation in rotation-invariant insulators