title: Non-Lifshitz-Kosevich field- and temperature-dependent amplitude of quantum oscillations in the quasi-two dimensional metal θ-(ET)₄ZnBr₄(C₆H₄Cl₂).
abstract: According to band structure calculations, the Fermi surface of the quasi-two dimensional metal θ-(ET)4ZnBr4(C6H4Cl2) 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 their 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.
authors.affiliation: Laboratoire National des Champs Magnétiques Intenses (UPR 3228 CNRS, INSA, UJF, UPS) 143 avenue de Rangueil, F-31400 Toulouse, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Audouard
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Fortin
authors.forename: David
authors.initials: D
authors.lastname: Vignolles
authors.forename: Rustem B
authors.initials: RB
authors.lastname: Lyubovskii
authors.forename: Loïc
authors.initials: L
authors.lastname: Drigo
authors.forename: Gena V
authors.initials: GV
authors.lastname: Shilov
authors.forename: Fabienne
authors.initials: F
authors.lastname: Duc
authors.forename: Elena I
authors.initials: EI
authors.lastname: Zhilyaeva
authors.forename: Rimma N
authors.initials: RN
authors.lastname: Lyubovskaya
authors.forename: Enric
authors.initials: E
authors.lastname: Canadell