Modern Physics Teaching

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From Physlab.lums.edu.pk

Modern Physics

Instructor: Dr. [Sabieh Anwar] Office hours: Monday, (2-6 pm); Friday, (3-5 pm)

Teaching Fellows: [Shahid Sattar] Office hours: Wednesday(12-3 pm), Thursday(12-3 pm) and [Shama Rashid] Office hours: Monday, Tuesday and Thursday (3-5 pm)

Textbook: Quantum Physics of Atoms, Molecules, Solids, Nuclei and Particles by R. Eisberg and R. Resnick. (The book is available in the library for Rs. 1100.)

Week 1

Blackbody radiation
Spectral radiance (experimental results); Stefan's and Wien's displacement law
Density of modes and average energies using principle of equipartition of energy
Rayleigh-Jeans formula
Planck's correction
Energy is quantized!

Homework No. 1
Blackbody Radiation
HW Solution

Week 2

Particle nature of electromagnetic radiation
The photoelectric effect
Compton Scattering
What are X-rays?
Pair production and Pair annihilation
Light:particles or waves?

Homework No. 2
Photoelectric effect, Compton effect, and X-rays
HW Solution

Week 3

Wave-particle duality and de Broglie relationship
Electron diffraction and interference (some original experiments)
Matter waves and wave packets
Relationship between position and momentum spaces and origins of Uncertainty principle

Homework No. 3
Pair production, Bragg's reflection, De Broglie's hypothesis and Uncertainty principle
HW Solution

Week 4

Uncertainty principle (position and momentum; energy and time)
Atomic spectroscopy and lifetime broadening
Bohr's model
The concept of reduced mass
Sommerfeld and Wilson's quantization

Homework No. 4
Uncertainty principle, Bohr's model, Sommerfeld's quantization
HW Solution

Weeks 5 and 6

Motivation for the Schrodinger Equation
Wavefunction and its probabilistic interpretation
Expectation values, legitimate definition
Corresponding principle
Time independent Schrodinger Equation
Solving the Schrodinger Equation for a free particle

Homework No. 5
Schordinger wave equation and its applications
HW Solution

Modern Physics conceptual survey result

Week 7

Acceptable solutions of the Schrodinger Equation; legitimate wavefunctions
Particle in an infinite well

Week 8 (This weak is devoted to revisions and addressing misconceptions)

How do electrons get across nodes? Explanation This is not an easy question to answer. The simplest answer to the question is to stop thinking of the electron as a classical point particle behaving like a sphere. Rather, the best and the only way to describe the electron is through its wavefunction spread out in space. Then everything follows from there. I will discuss this further in the class.

Midterm examanination
Question paper
Solution set
Barchart of MCQ responses
Histogram of mid-term grades

Weeks 9 and 10

scanning tunneling microscope image of 5 nm gold nanoparticles (photograph by Dhirani)

STM of a silicon surface, showing individual silicon atoms (photograph by IBM)

Particle in a finite well (do-it-yourself)
Step potential when energy is less than the potential height
Step potential when energy is greater than the potential height
Barrier potential, quantum mechanical tunneling, reflectivity and transmittivity
Ramseur effect, size resonance
Analogies with optics:
- reflectivity from a dielectric
- total internal reflection and evanescent waves
- frustrated total internal reflection
Scanning tunneling microscopy
Schottky barrier
Field emission: metal placed in an electric field

Homework No. 6
Potential barrier, steps and wells
HW Solution

Week 11

The H atom
Solving the three dimensional Schrodinger equation for a spherical potential
Origin of principal, azimuthal and orbital quantum numbers
orbitals: s, p, d and f
full derivation of spherical harmonic functions as solutions of the polar part of Schrodinger's equation

3D H atom orbital viewer
Complete solution of the angular part of the Schrodinger Equation

Homework No. 7
Finite wells and the tunneling effect
HW Solution

Weeks 12 and 13