Fermi surface

Fermi surface and f-electron
The study of Fermi surface have contributed to the physics of heavy-fermion system. The Fermi surface reveals the state of 4f electron whether local or itinerant. And the splitting of the Fermi surfaces is direct evidence for non-centrosymmetric system. To elucidate the Fermi surface, we perform de Haas - van Alphen (dHvA) effect experiment. This is also tells us a cyclotron effective mass. To observe a heavy mass, we need extremely low temperature and high magnetic field conditions.

The figures below show the angular dependence of dHvA frequency and a hand-made Fermi surface of Cu. The shape of the Fermi surface is almost-spherical but connects to each other along the <111> direction (neck).