PA4311 Quantum Theory of Solids Quantum Theory of Solids Mervyn Roy (S6) www2.le.ac.uk/departments/physics/people/mervynroy
PA4311 Quantum Theory of Solids 1.Introduction and background 2.The many-electron wavefunction - Introduction to quantum chemistry (Hartree, HF, and CI methods) 3.Introduction to density functional theory (DFT) - Framework (Hohenberg-Kohn, Kohn-Sham) - Periodic solids, plane waves and pseudopotentials 4.Linear combination of atomic orbitals 5.Effective mass theory 6.ABINIT computer workshop (LDA DFT for periodic solids) Assessment: 70% final exam 30% coursework – mini ‘project’ report for ABINIT calculation Course Outline
PA4311 Quantum Theory of Solids Last time…
PA4311 Quantum Theory of Solids Periodic structures and plane waves 223 course notes Solid state text books – e.g. Tanner, Introduction to the Physics of Electrons in Solids, Cambridge University press Hook and Hall, Solid State Physics 2 nd Ed., John Wiley and Sons Ashcroft and Mermin, Solid State Physics, Holt-Saunders
PA4311 Quantum Theory of Solids graphene unit cell Crystal = Bravais lattice + basis
PA4311 Quantum Theory of Solids 2D crystal – many choices for unit cell Hexagonal lattice, 2 atom basis Wigner-Seitz (primitive) Primitive Primitive centred Non-primitive
PA4311 Quantum Theory of Solids wikipedia.org 3D crystal: zinc blende structure (diamond, Si, GaAs etc)
PA4311 Quantum Theory of Solids
Wigner-Seitz cell in reciprocal space = Brillouin zone
PA4311 Quantum Theory of Solids FCC Reciprocal lattice = BCC recip Léon Brillouin ( ): most convenient primitive cell in reciprocal space is the Wigner-Seitz cell - edges of BZ are Bragg planes. Brillouin Zone
PA4311 Quantum Theory of Solids Question 3.1
PA4311 Quantum Theory of Solids conduction band valence band (heavy holes) doubly degenerate band (no spin orbit coupling)
PA4311 Quantum Theory of Solids Fourier representation of a periodic function
PA4311 Quantum Theory of Solids Bloch theorem plane wave part
PA4311 Quantum Theory of Solids Question 3.2