Aperiodic quantum oscillations of particle-hole asymmetric Dirac cones

• Published in: Europhysics letters Vol. 119; no. 6; pp. 67001 - 67005
• Main Authors: Tisserond, E., Fuchs, J. N., Goerbig, M. O., Auban-Senzier, P., Mézière, C., Batail, P., Kawasugi, Y., Suda, M., Yamamoto, H. M., Kato, R., Tajima, N., Monteverde, M.
• Format: Journal Article
• Language: English
• Published: Les Ulis EDP Sciences, IOP Publishing and Società Italiana di Fisica 01.09.2017; IOP Publishing; European Physical Society / EDP Sciences / Società Italiana di Fisica / IOP Publishing
• Subjects: 72.80.Le; 73.43.Qt; 75.47.-m; Asymmetry; Chemical Sciences; Cones; Hydrostatic pressure; Oscillations; Zeeman effect; magnetotransport measurements; electrocrystallisation; Dirac cone system; α-(BEDT-TTF)2I3
• ISSN: 0295-5075; 1286-4854
• DOI: 10.1209/0295-5075/119/67001

We report experimental measurements and theoretical analysis of Shubnikov-de Haas (SdH) oscillations in a Dirac cone system: the α-(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 α-(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 α-(BEDT-TTF)2I3 samples with different Fermi levels.