Quantum oscillations

Quantum oscillations are determined by the Landau quantization of the energy levels of metals in high magnetic fields and are usually observed at very low temperatures and in very clean single crystalline metallic materials. Quantum oscillations experiments allow to map out the Fermi surface by following the angular dependence of its extremal areas normal to the applied magnetic field. Furthermore, quantum oscillations allow to extract information about the masses and the mean free path of the quasiparticles and the degree of electronic correlations in various strongly correlated electronic systems.

The quantum oscillations observed in the thermodynamic properties (magnetization, torque, specific heat) give rise to the de Haas van Alphen effect (dHvA) whereas when they are observed in transport properties give rise to the Shubnikov-de Haas effect.

Figure1. Quantum oscillations measured in a superconducting magnet (March 2011) on a 70 micron size crystal. Left panel show raw oscillatory torque data and the right panel the fast Fourier transform that is directly related to the extremal areas of the Fermi surface normal to the applied magnetic field for a particular orientation.

For a recent review on quantun oscillations on iron-pnictide superconductors and metals see Phil. Trans. R. Soc. A 13 August 2010 vol. 368 no. 1924 3503-3517 .