Solution
= Solution
<Bloch theorem> $|k\rangle\propto\sum_Re^{ik\cdot R}|R\rangle$ are eigenstates with $E(k)=E_0-2\mu\sum_{i=1}^3\cos(k\cdot a_i)$.
= Solution
<Bloch theorem> $|k\rangle\propto\sum_Re^{ik\cdot R}|R\rangle$ are eigenstates with $E(k)=E_0-2\mu\sum_{i=1}^3\cos(k\cdot a_i)$.