Dingle factor ($R_D=\exp [-\pi /({\omega }_c{\tau }_q)]$)

The Dingle factor describes the damping of quantum oscillations by Landau-level broadening. For a Lorentzian half-width $\hslash /(2{\tau }_q)$, the fundamental harmonic has $R_D=\exp [-\pi /({\omega }_c{\tau }_q)]$. Since ${\omega }_c$ decreases with field, the amplitude decays at large inverse field. The lifetime here is the quantum lifetime, not automatically the mobility-derived transport time.