Fourier analysis of the de Haas–van Alphen oscillations in two-dimensional electron systems with background reservoir states

Abstract

A Fourier analysis of the de Haas--van Alphen (dHvA) oscillations in a two-dimensional (2D) electron system with background (magnetically unperturbed) reservoir states is presented. The method is exploited in a systematic study of the various wave forms of the oscillations observed in dHvA and Shubnikov--de Hass measurements on quasi-2D organic metals. It is found that at relatively moderate background strengths both the first and the second harmonics exhibit qualitative deviations from the well known Lifshitz-Kosevich-Shoenberg formula. In particular, it is found that by varying the temperature (or the magnetic field) at certain strengths of the background reservoir, the wave form can be changed from leftward to rightward asymmetry (while the second harmonic changes sign).