Non-Lifshitz-Kosevich field-and temperature-dependent amplitude of quantum oscillations in the quasi-two dimensional metal θ-(ET) 4 ZnBr 4 (C 6 H 4 Cl 2 )

Alain Audouard (1) , Jean-Yves Fortin (2) , David Vignolles (1) , Rustem I Lyubovskii (3) , Loïc Drigo (1) , Gena V. Shilov (4) , Fabienne Duc (1) , Elena I Zhilyaeva (3) , Rimma N Lyubovskaya (3) , Enric Canadell (5)

1 LNCMI-T - Laboratoire national des champs magnétiques intenses - Toulouse
2 IJL - Institut Jean Lamour
3 Institute for Problems of Chemical Physics
4 IPCP - Institute of Problems of Chemical Physics
5 ICMA-CSIC - Instituto de Ciencia de Materiales de Aragón [Saragoza, España]

According to band structure calculations, the Fermi surface of the quasi-two dimensional metal θ-(ET) 4 ZnBr 4 (C 6 H 4 Cl 2) illustrates the linear chain of coupled orbits model. Accordingly, de Haas-van Alphen oscillations spectra recorded in pulsed magnetic field of up to 55 T evidence many Fourier components, the frequency of which are linear combinations of the frequencies relevant to the closed α and the magnetic breakdown β orbits. The field and temperature dependence of these component's amplitude are quantitatively accounted for by analytic calculations including, beyond the Lifshitz-Kosevich formula, second order terms in damping factors due to the oscillation of the chemical potential as the magnetic field varies. Whereas these second order terms are negligible for the orbits α, β and 2β − α, they are solely responsible for the 'forbidden orbit' β − α and its harmonic and have a significant influence on Fourier components such as 2α and β + α, yielding strongly non-Lifshitz-Kosevich behaviour in the latter case.

Mots clés: De Haas-Van Alphen oscillations; high magnetic fields; two-dimensional organic metals

Domaines: Electrons fortement corrélés [cond-mat.str-el]; Supraconductivité [cond-mat.supr-con]

Alain Audouard, Jean-Yves Fortin, David Vignolles, Rustem I Lyubovskii, Loïc Drigo, et al.. Non-Lifshitz-Kosevich field-and temperature-dependent amplitude of quantum oscillations in the quasi-two dimensional metal θ-(ET) 4 ZnBr 4 (C 6 H 4 Cl 2 ). Journal of Physics: Condensed Matter, 2015, 27 (31), pp.315601. ⟨10.1088/0953-8984/27/31/315601⟩. ⟨hal-01166810v2⟩