The influence of the chemical potential oscillations on the de Haas-van Alphen effect in quasi-two-dimensional compounds

Abstract

The de Haas -van Alphen effect in quasi-two-dimensional metals is studied at arbitrary parameters. The oscillations of the chemical potential may substantially change the temperature dependence of harmonic amplitudes that is usually used to determine the effective electron mass. Hence, the processing of the experimental data using the standard Lifshitz-Kosevich formula (that assumes the chemical potential to be constant) may lead to substantial errors even in the limit of strong harmonic damping. This fact may explain the difference between the effective electron masses, determined from the de Haas -van Alphen effect and the cyclotron resonance measurements. The oscillations of the chemical potential and the deviations from the Lifshitz-Kosevich formula depend on the reservoir density of states, that exists in organic metals due to open sheets of Fermi surface. This dependence can be used to determine the density of electron states on open sheets of Fermi surface. We present the analytical results of the calculations of harmonic amplitudes in some limiting cases that show the importance of the oscillations of the chemical potential. The algorithm of the simple numerical calculation of the harmonic amplitudes at arbitrary reservoir density of states, arbitrary warping, spin-splitting, temperature and Dingle temperature is also described.The quantum magnetization oscillations (or the de Haas -van Alphen (dHvA) effect) was discovered long ago [1] and has been used a lot as a powerful tool for studying the Fermi surfaces and single electron properties in metals [2]. In three dimensional (3D) metal the good quantitative description of this effect is given by the Lifshitz-Kosevich(L-K) formula [3]. In two-or quasi-twodimensional compounds the deviations from the L-K formula are possible for three reasons: the harmonic damping in two-dimensional (2D) case is different, the impurity scattering may not be described by the usual Dingle law and the chemical potential becomes also an oscillating function of the magnetic field. The first problem is important only when the harmonic damping is weak and can be easily solved by using the 2D harmonic expansion [2]. The second problem concerns with 1

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“…A large number of papers ( [28] and references in this paper) are devoted to the study of the conductivity of quasi-two-dimensional (2D) multilayer systems in a magnetic field. The growing interest is due to: (i) the fact that the conductivity measurement is technologically implemented for almost any system; (ii) the electrical conductivity in the magnetic field is very sensitive to the parameters of the electronic structure, revealing the restructuring of the law of dispersion and geometry of the Fermi surface.…”

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Enhancements of the 32 and 52 frequencies of de Haas–van Alphen oscillations near the Lifshitz transition in a two-dimensional compensated metal with overtilted Dirac cones

“…In this section we explain the calculations of the total energy and magnetization as a function of external magnetic field in two situations; one is the case of the fixed electron number and the other is the case of the fixed chemical potential. The first case, the fixed electron number or fixed electron filling to be 3/4, is plausible in the isolated two-dimensional systems [1,6,7,9,15,17,24]. The fixed chemical potential is realized if there exist the electron reservoirs, the three-dimensionality or the thermal broadening.…”

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