Physics 451

1
Physics 451

• Quantum mechanics I
• Fall 2011

Nov 16, 2010 Karine Chesnel
2
Quantum mechanics
Announcements

• Homework this week
• HW 20 Thursday Nov 17 by 10pm

Practice Test 3 review Friday Nov18
Test 3 Saturday Nov 19 Tuesday Nov 22
3
Quantum mechanics
The spin
4
Quantum mechanics
Spin ½ and Pauli matrices
up
down
in the spinors space
5
Quantum mechanics
State of the electron
Pb 4.27, 4.28, 4.29
6
Quantum mechanics
Quiz 29a
When measuring Sx on an electron, what are the
possible results?
7
Quantum mechanics
Adding spins
8
Quantum mechanics
Adding spins 1/2
possibilities
9
Quantum mechanics
Adding spins 1/2
Magnitude of the spin momentum ?
10
Quantum mechanics
Adding spins S
Pb 4.34, 4.35
11
Quantum mechanics
Clebsch- Gordan coefficients
12
Quantum mechanics
Quiz 29b
What is the value of the Clebsch-Gordan
coefficient ?
13
Quantum mechanics
The spin and magnetic field
14
Quantum mechanics
The spin and magnetic field
15
Quantum mechanics
Larmor precession
B
S
Pb 4.32
16
Quantum mechanics
Stern-Gerlach experiment
z
B
Moves down
Moves up