UNC-CH P&A 
Classes Physics and Astronomy

Physics 871: Problem set 4

  1. The graph above is from Kittel's Quantum Theory of Solids Ed. 1. The caption claims that it represents the free electron bands in the [111] direction for a monatomic simple cubic lattice. It takes units of lattice spacing a = 1, and ℏ = 1. It was embarrassingly botched: at least one branch is missing, and the degeneracies (in parentheses) are a mess. Correct it.

  2. Calculate the band energies E(k) for (a) nearly free electrons and (b) a tight binding lattice. In (b) the monatomic cubic lattice with cell side a is populated with noble gas atoms that have spherically symmetric electron orbitals, and only nearest neightbor interactions matter. Calculate bandwidths and energy gaps and compare them for the two cases.

  3. M & A problem 25.3.






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