Bloch states and electronic bands
A periodic crystal potential organizes energies by wavevector and band.
Key knowledge
For a periodic one-electron Hamiltonian, Bloch states have ψ_nk(r) = e^(ik·r)u_nk(r), with u_nk(r+R) = u_nk(r) for lattice vectors R. Their energies E_n(k) form bands.
Values and equations
ψ_nk(r) = e^(ik·r)u_nk(r); u_nk(r+R) = u_nk(r); energy E_n(k)
- ψ_nk, u_nk
- State and lattice-periodic part in a chosen normalization
- k
- Crystal wavevector m⁻¹
- r, R
- Position and lattice translation m
- n
- Band index
- E_n(k)
- Band energy J
Conditions and scope
- Ideal periodic crystal and independent-electron or effective one-electron model; boundaries and disorder need additional treatment.
- Crystal wavevector is not generally the free-particle mechanical momentum; strong correlations can invalidate the simple band description.
Sources · 2
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
MIT slides 35–43: periodic potential, Bloch form and indexed band energies; OpenStax band/gap description.
2026-10-10 · Periodic one-electron band structure only; the textbook's universal 1 eV semiconductor cutoff is excluded.
Entry details
Permanent link to this entry ↗- Record identity
- physics-band-structure
- Revision
- university-reference.1
- Structured reference record
- University reference · University core expansion