Physics 451 Quantum mechanics I Fall 2012 Nov 30, 2012 Karine Chesnel
Test 3 Last day Today! Quantum mechanics HW 23 Tuesday Dec 4 HW 24 Thursday Dec 6 Homework
Periodic table Quantum mechanics Filling the shells 226 s: “sharp” p: “principal” d: “diffuse” f: “fundamental”
Periodic table Quantum mechanics Filling the shells
Periodic table Quantum mechanics Spectroscopic symbol
Periodic table Quantum mechanics Hund’s rules First rule: seek the state with highest possible spin S (lowest energy) Second rule: for given spin S, the state with highest possible angular momentum L has lowest energy Third rule: If shell no more than half filled, the state with J=IL-SI has lowest energy If shell more than half filled, the state with J=L+S has lowest energy
Periodic table Quantum mechanics
Quiz 31 Quantum mechanics What is the spectroscopic symbol for Silicon ? A. B. C. D. E. Si: (Ne)(3s) 2 (3p) 2
Periodic table Quantum mechanics Filling the shells 226 s: “sharp” p: “principal” d: “diffuse” f: “fundamental”
Periodic table Quantum mechanics Filling the shells
Quantum mechanics
Periodic table Quantum mechanics Spectroscopic symbol
Periodic table Quantum mechanics
Periodic table Quantum mechanics Hund’s rules First rule: seek the state with highest possible spin S (lowest energy) Second rule: for given spin S, the state with highest possible angular momentum L has lowest energy Third rule: If shell no more than half filled, the state with J=L-S has lowest energy If shell more than half filled, the state with J=L+S has lowest energy
Quiz 33 Quantum mechanics What is the spectroscopic symbol for Silicon ? A. B. C. D. E. Si: (Ne)(3s) 2 (3p) 2
Quiz 33 Quantum mechanics What is the spectroscopic symbol for Chlorine ? A. B. C. D. E. Cl: (Ne)(3s) 2 (3p) 5
Solids Quantum mechanics e-e- What is the wave function of a valence electron in the solid?
Solids Quantum mechanics e-e- Basic Models: Free electron gas theory Crystal Bloch’s theory
Free electron gas Quantum mechanics e-e- e-e- lzlz lyly lxlx Volume Number of electrons:
Free electron gas Quantum mechanics e-e- 3D infinite square well 0 inside the cube outside
Free electron gas Quantum mechanics e-e- Separation of variables
Free electron gas Quantum mechanics Bravais k-space Volume of unit cell
Quiz 33c Quantum mechanics A. 1 B. 2 C. q D. Nq E. An infinity How many electrons can be contained in one unit cell in the Bravais k- lattice ?
Free electron gas Quantum mechanics Bravais k-space Fermi surface Free electron density
Free electron gas Quantum mechanics Bravais k-space Fermi surface Total energy contained inside the Fermi surface
Free electron gas Quantum mechanics Bravais k-space Fermi surface Solid Quantum pressure arises from Pauli exclusion principle
Solids Quantum mechanics e-e- Bravais k-space Fermi surface Number of unit cells