Onsager phase factor of quantum oscillations in the organic metal theta-(BEDT-TTF)4CoBr4(C6H4Cl2)

Alain Audouard (1) , Jean-Yves Fortin (2) , David Vignolles (1) , Rustem B. Lyubovskii (3) , Elena I. Zhilyaeva (3) , Rimma N. Lyubovskaya (3) , Enric Canadell (4)

1 LNCMI-T - Laboratoire national des champs magnétiques intenses - Toulouse
2 IJL - Institut Jean Lamour
3 IPCP - Institute of Problems of Chemical Physics
4 ICMAB - Institut de Ciència de Materials de Barcelona

De Haas-van Alphen oscillations are studied for Fermi surfaces illustrating the Pippard's model, commonly observed in multiband organic metals. Field- and temperature-dependent amplitude of the various Fourier components, linked to frequency combinations arising from magnetic breakdown between different bands, are considered. Emphasis is put on the Onsager phase factor of these components. It is demonstrated that, in addition to the usual Maslov index, field-dependent phase factors must be considered to precisely account for the data at high magnetic field. We present compelling evidence of the existence of such contributions for the organic metal theta-(BEDT-TTF)4CoBr4(C6H4Cl2).

Mots clés: organic metals de Haas-van Alphen oscillations magnetic breakdown

Domaines: Electrons fortement corrélés [cond-mat.str-el]

Alain Audouard, Jean-Yves Fortin, David Vignolles, Rustem B. Lyubovskii, Elena I. Zhilyaeva, et al.. Onsager phase factor of quantum oscillations in the organic metal theta-(BEDT-TTF)4CoBr4(C6H4Cl2). Synthetic Metals, 2013, 171, pp.51-55. ⟨10.1016/j.synthmet.2013.03.011⟩. ⟨hal-00817426⟩