Physics
302 2007 Lecture summaries and lecture notes.
These are the lecture notes for Physics 302 - Advanced Quantum
Mechanics
taught in Spring 2007.
How to read these lecture notes:
Each page has 4 panels, representing a chunk of blackboard about 3 feet
wide. The sequence of panels on a page is TL, TR, BL, BR. A 55
minute lecture is usually ten
panels, 2.5 pages.
Note on errata: I'd
be grateful, if you find a mistake, if you let me know so I can
note it here.
Readings are from Townsend: A modern approach to quantum mechanics
- Lecture
1: M 01/22/07, Why we need quantum mechanics.
Introduction to Gaussian units. Reading: Appendix A pp 444-448
- Lecture
2: W 01/24/07, The Stern - Gerlach experiment. Four
different experiments. Reading: Chapter 1 Section 1.1 pp 1-5, Section
1.2 pp 5-9
- Lecture
3: F 01/26/07 The quatum state vector and analysis of the
four Stern Gerlach experiments. Chapter 1 Section 1.3 pp 9-13, Section
1.4 pp 13-15, Section 1.5 pp 15-18, Section 1.6 pp 18-21
- Lecture
4: M 01/29/07 Analyzing Stern Gerlach experiments using
the quantum state vector. Freedom of representation and change of
basis. Reading: Section 1.5 pp 15-18, Section 1.6 pp 18-21 Section 2.1
pp 24-28
- Lecture
5: W 01/31/07 Rotation operators. The identity and
projection operators. Matrix representation of operators. Reading:
Section 2.2 pp 28-35, Section 2.3 pp 36-41 Section 2.4 pp 41-45
- Lecture
6: F 02/02/07 Changing representation. The polarization
of the photon. Reading: Section 2.5 pp 45-50, Section 2.6 pp 50-51,
Section 2.7 pp 51-56
- Lecture
7 M 02/05/07 Action of rotations on vectors in lab and in
Hilbert space. Matrix elements of components of angular momentum $\hat
J_x$, $\hat J_y$, $\hat J_z$. An arbitrary unitary operation on a spin
$\frac{1}{2}$ system can be made up of three rotations. Reading:
Section 2.2 pp 28-35. Section 2.4 pp 41-45 Section 2.5 pp 45-50
- Lecture
8 W 02/07/07 Review of formalism. States
$\leftrightarrow$ Hilbert space unit vectors, Observables
$\leftrightarrow$ Hermitian operators etc. Expectation values.
Projections and measurements. Reading: Section 2.8 pp 56-61 Section 2.3
pp 36-41
- Lecture
9 F 02/09/07 Completeness of basis and change of basis of
operators. Schroedinger picture vs. Heisenberg picture. Non- commuting
operators and angular momentum. Commuting operators. Reading: Section
2.4 pp 41-45
- Lecture
10 M 02/12/07 Commutation relations for generators of
rotations. Defining angular momentum via commutation relations.
Reading: Section 3.1 pp 64-69 Section 3.2 pp 69-70
- Lecture
11 W 02/14/07 Eigenvalues of the angular momentum
operators. Reading: Section 3.3 pp 70-77
- Lecture
12 F 02/16/07 Raising and lowering operators. Matrix
elements of raising and lowering operators. Reading: Section 3.3 pp
70-77 Section 3.4 pp 77-78
- Lecture
13 M 02/19/07 Commutation relations and eigenvalues of
angular momentum operators. Reading: Section 3.2 pp 69-70, Section 3.3
pp 70-77
- Lecture
14 W 02/21/07 Commutation relations and Matrix Elements,
Commutation relations and Uncertainty relations. Reading: Section 3.4
pp 77-78, Section 3.5 pp 78-80
- Lecture
15 F 02/23/07 Summary of angular momentum, examples for
spin $1/2$ and spin $1$. Reading: Section 3.6 pp 80-85, Section 3.7 pp
85-87, Section 3.8 pp 88-90
- Lecture
16 M 02/26/2007 Commutation relations and the Uncertainty
principle. Time dependence and the Hamiltonian. Reading: Section 3.5 pp
78-80 Section 4.1 pp 93-96 Section 4.2 pp 96-97
- Lecture
17 W 02/28/2007 A Spin-$\frac{1}{2}$ particle in a
magnetic field. Reading: A Spin-$\frac{1}{2}$ particle in a magnetic
field.
- Lecture
18 F 03/02/2007 Spin dynamics and magnetic resonance.
Reading: Section 4.4 pp 104-108
- Lecture
19 M 03/05/2007 Basis states and addition of angular
momentum for a system of two spin $\frac{1}{2}$ particles. Reading:
Section 5.1 pp 120-122, {\em Section 5.2 pp 122-126 This section not
covered in lecture} Section 5.3 pp 126-131
- Lecture
20 W 03/07/2007 The EPR paradox and the Bell
inequalities. Reading: Section 5.4 pp131-134, Section 5.5 pp 134-143.
- Lecture 21 F 03/09/2007 Class visit by Jerry Gollub - The EPR and
Bohr discussion ``Can quantum mechanical description of reality be
considered complete'' Einstein Podolsky Rosen Paradox
- Lecture
22 M 03/12/2007 Continuous variables: position
eigenstates. The translation operator and linear momentum.
Reading: 6.1 Position Eigenstates and the Wave
Function pp147-151, 6.2 The
Translation Operator pp151-153, 6.3
The Generator of Translations pp153-156,
6.4 The Momentum Operator in the Position
Basis pp156-158 Relevant problems: 6.1, 6.2, 6.3, 6.7
- Lecture
23 W 03/14/2007 The relationship between the position and
momentum bases. The fourier transform and the Heisenberg uncertainty
principle. Reading:6.5 Momentum
Space pp158-160, 6.6 A Gaussian
Wave Packet pp160-164, 6.7 The
Heisenberg Uncertainty Principle pp164-166 Relevant
problems: 6.4, 6.5, 6.6
- Lecture
24 F 03/16/2007 Simple properties of 1-D wave mechanics.
Particle in a box. Reading: 6.8 General Properties of
Solutions to the Schrodinger Equation in Position
Space pp166-171, 6.9 The Particle
in a Box pp171-177 Relevant problems: 6.8, 6.9
6.10, 6.11, 6.12, 6.13, 6.14, 6.15, 6.16
- Lecture
25 M 03/19/2007 Scattering in quantum mechanics.
Incident, Reflected and Transmitted amplitudes from a step. Reading:
6.10 Scattering in One Dimension
177, 6.11 Summary 185, Relevant
Problems 6.17, 6.18, 6.19, 6.20, 6.21
- Lecture
26 W 03/21/2007 Professor Eddie Farhi, MIT Center for
Theoretical Physics class visit - presentation of ``A Quantum Algorithm
for the Hamiltonian NAND Tree'' Reading:
www.arxiv.org/quant-ph/0702144}, ``A Quantum Algorithm for the
Hamiltonian NAND Tree'', E. Farhi, J. Goldstone, S. Gutmann
(Lecture given in recitation)
- Lecture
27 F 03/23/2007 The simple harmonic oscillator -
operators and wavefunctions. Reading: 7.2 Operator
Methods 196, 7.4 Matrix Elements of
the Raising and Lowering Operators 201,
7.5 Position-Space Wave Functions
202, Relevant problems 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7
- Lecture
28 M 03/26/2007 Properties of the simple harmonic
oscillator - zero point energy, classical correspondence, time
dependence and symmetry. Reading: 7.6 The Zero-Point
Energy 205, 7.7 The Classical
Limit 207, 7.8 Time
Dependence 208, 7.10 Inversion
Symmetry and the Parity Operator 212, Relevant
problems: 7.7, 7.8, 7.9, 7.11, 7.12
- Lecture
29 W 03/28/2007 Translations and momentum in three
dimensions. Reading: 9.1 The Elements of Wave
Mechanics in Three Dimensions 237
9.2 Translational Invariance and Conservation of
Linear Momentum 241, 9.3 Relative
and Center-of-Mass Coordinates 244. Relevant problems: 9.1,
9.2, 9.4, 9.5
- Lecture
30 F 03/30/2007 Centre of mass coordinates. Estimating
Ground-State Energies Using the Uncertainty Principle.
9.4 Estimating Ground-State Energies Using the
Uncertainty Principle 246, Relevant problems: 9.6, 9.7, 9.8
- Lecture
31 M 04/02/2007 Rotational invariance and conservation of
angular momentum in three dimensions. Complete commuting observables
for problems with spherical symmetry. Reading: 9.5 Rotational
Invariance and Conservation of Angular Momentum 248 9.6 A Complete
Set of Commuting Observables 250
- Lecture
32 W 04/04/2007 Angular momentum in position space (back
to $\hat{\bf L}=\hat{\bf r}\times\hat{\bf p}$) and the spherical
harmonics. Reading: 9.8 Position-Space
Representations of L in Spherical Coordinates 260,
9.9 Orbital Angular Momentum
Eigenfunctions 263 Relevant problems 9.12, 9.13,
9.14, 9.15, 9.16, 9.17, 9.18
- Lecture
33 F 04/06/2007 Solving the angular eigenvalue problem -
the Spherical Harmonics Reading: 9.10
Summary 268 - Additional reading from Boas, Methods
of Mathematical Physics.
- Lecture
34 M 04/09/2007 Reading: 10 Bound
States of Central Potentials 274
10.1 The Behavior of the Radial Wave Function Near
the Origin 274 10.2 The Coulomb
Potential and the Hydrogen Atom 277,
10.3 The Finite Spherical Well and the
Deuteron 288
- Lecture
35 W 04/11/2007 Reading: 10.4 The
Infinite Spherical Well 292,
10.5 The Three-Dimensional Isotropic Harmonic
Oscillator 296 10.6
Conclusion 302
- Lecture 36 F 04/13/2007 Reading: 11
Time-Independent Perturbations 306
11.1 Nondegenerate Perturbation
Theory 306 11.2 An Example
Involving the One-Dimensional Harmonic Oscillator 311
- Lecture
37 M 04/16/2007 Reading: 11.3
Degenerate Perturbation Theory 314
11.4 The Stark Effect in Hydrogen
316 11.6 Relativistic Perturbations to the Hydrogen
Atom 322
- Lecture
38 W 04/18/2007 Reading: 11.7 The
Energy Levels of Hydrogen, Including Fine Structure, the Lamb Shift,
and Hyperfine Splitting 331
- Lecture
39 F 04/20/2007 Reading: 11.8 The
Zeeman Effect in Hydrogen 334 11.9
Summary 335
- Lecture
40 M 04/23/2007 Reading: 14.6
Time-Dependent Perturbation Theory 417,
14.7 Fermi's Golden Rule 425
- Lecture
41 W 04/25/2007 Reading: 14.2 The
Hamiltonian for the Electromagnetic Field 404,
14.3 Quantizing the Radiation Field
409, 14.4 The Properties of Photons
410, 14.5 The Hamiltonian of the Atom and the
Electromagnetic Field 414
- Lecture 42 F 04/27/2007 Reading:14.8
Spontaneous Emission 430, 14.9
Higher-Order Processes and Feynman Diagrams 437