Estimation of the cyclotron effective mass from the de-Haas-van Alphen oscillation in quasi-two-dimensional organic conductors

The cyclotron effective mass is obtained by fitting a temperature-dependence of the Fourier transform integrals of the dc Haas-van Alphen (dHvA) oscillation with Lifehitz-Kosevich (LK) formula. However, the LK formula should be applied carefully in two-dimensional (2D) and quasi-two-dimensional (Q2D) systems at low temperatures, where the magnetic-field-dependence of the chemical potential cannot be neglected. We derive a cross-over temperature above which we can use the LK formula for the estimation of the cyclotron mass even in 2D and Q2D systems. We also show the cross-over temperature of κ-(BEDT-TTF)2Cu(NCS)2 which is known as the quasi-two-dimensional organic conductor.