Condensed Matter II
Problem set #5
Spring 2023
1 Density of states of Si, Ge, Sn
Figure 1: Band structure (a)Si and (b)Ge.
Based on the density of states of Si, Ge, and α-Sn displayed in Fig 2, comment on the
density of states of the empty diamond lattice (assuming isotropic effective mass m0 and
lowest energy point of the density of states at E0 = −13 eV). Where is the Fermi energy
located?
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Figure 2: Calculated electronic densities of states compared to experiment for Si, Ge, and
α-Sn. The experimental results for Si and Ge are from Pollak et al., PRL 29, 1103 (1973)
and Grobman et al., PRL 29, 1508 (1972) respectively. In the case of Si, two results are
displayed: nonlocal pseudopotential (solid line) and local pseudopotential (dashed line).
R. Chelikowsky et al., PRB 14, 556 (1976)
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