Set of supplementary notes.

6.3. QUANTUM OSCILLATIONS – DE HAAS VAN ALPHEN EFFECT 91
Figure 6.5: Photoemission spectra on the two dimensional layered metal Sr 2 RuO 4 . The bands
are nearly two-dimensional in character, so the interpretation of the photoemission data is
straightforward – different angles (see Fig. 6.3 )correspond to different in-plane momenta. The
upper panels show energy scans for different angles that correspond to changing the in-plane
momentum in the direction from the centre of the Brillouin zone Γ towards the centre of the
zone face M and the corner X. Several bands cross the Fermi energy, with different velocities,
and sharpen as their energies approach E F . The left hand lower panel plots the positions of the
peaks as a function of momentum at the Fermi energy, to be compared with the band structure
calculation of the Fermi surface(s) on the lower right. [Experiment from Damascelli et al, PRL;
theory from Mazin et al PRL 79, 733 (1997)]