Quantum Mechanics II

Syllabus (under construction)


KKL - K. K. Likharev's Lectures on Quantum Mechanics
JJS - J.J. Sakurai's book
RRL - R. R. Liboff's book
MIT - MIT Open Courseware, Quantum Theory I
LL - L. D. Landau and E. M. Lifshitz, Quantum Mechanics
RS - R. Shankar, Principles of Quantum Mechanics
EM - E. Merzbacher, Quantum Mechanics
DJG - D. J. Griffiths, Introduction to Quantum Mechanics


# Date Read Topic
1. Tue, Jan 26 JJS 3.1-3.2 The theory of angular momentum. Translations. Rotations in three spatial dimensions. Generators of rotations. SU(2) algebra. Unitary transformations of a Hilbert space corresponding to rotations. Operators of angular momentum components. The simplest case of spin 1/2 system. Spintors, algebra of Pauli matrices, and transformations of linear operators under rotations.
2. Thu, Jan 28 JJS 3.6 Groups, Lie groups, Lie algebras, representation theory (some terminology). Infinitely dimensional case: orbital angular momentum.
3. Tue, Feb 2 JJS 3.5-3.6 Homework 12 is given. Eigenvalue problem for angular momenta. Ladder operators. (2j+1) dimensional representation. Matrix elements of angular momentum operators. Representations of rotation operator.
4. Thu, Feb 4 JJS 3.6-3.7 Orbital angular momentum and spherical harmonics. Angular momentum in coordinate representation. Eigenfunctions of L^2 are spherical harmonics. Legendre polynomials and associated Legendre functions. Addition of angular momenta. Example of two spin-1/2 systems.
5. Tue, Feb 9 JJS 3.7, 3.10 Homework 13 is given. Example of two spin-1/2 systems. Example of spin and orbital angular momenta. Formal theory of angular momentum addition. Clebsh-Gordan coefficients and their properties.
6. Thu, Feb 11 CLASS WAS CANCELLED BECAUSE OF SNOW STORM
7. Tue, Feb 16 JJS 3.10 Homework 14 is given. Properties of Clebsh-Gordan coefficients. Tensor operators. Cartesian and spherical tensors.
8. Thu, Feb 18 JJS 3.10, 3.4 Matrix elements of tensor operators. Wigner-Eckart theorem. Density operator. Density matrix.
9. Tue, Feb 23 JJS 3.4 Homework 15 is given. Density operator. Time evolution of density operator. Density operator in statistical mechanics. Entanglement.
10. Thu, Feb 25 JJS 4.1-3 Symmetries in Quantum Mechanics. Discrete symmetries. Parity. Polar and axial vectors, scalar and pseudoscalars. Even and odd wave functions. Parity of rotational states. Theorem of parity of eigenstates of H.
11. Tue, Mar 2 JJS 4.3-4.4 Homework 16 is given. Symmetric double-well potential. Parity selection rule. Other discrete symmetries (point groups, lattice translations). Time-reversal symmetry. Time-reversal symmetry in classical physics. Antiunitary operators. Construction of time-reversal (anti)symmetry operator.
12. Thu, Mar 4 JJS 4.4, 5.1 Time-reversal symmetry and reality of wave functions. Time-reversal for spin 1/2. Perturbation theory I. Time-independent case. Time-independent perturbation theory. Non-degenerate case. Example of two-level system.
13. Tue, Mar 9 JJS 5.1 Homework 17 is given. Perturbation theory expansion for non-degenerate case. Normalization of the wave function. Example: quadratic Stark effect.
14. Thu, Mar 11 JJS 5.2 Degenerate case. Secular equation. Example: linear Stark effect. Hydrogen atom. Estimate of the energy of the graound state. Bohr radius and Rydberg. Laguerre equation.
15. Tue, Mar 16 Midterm - one-hour exam (closed book). Three problems: 1) Angular momentum, 2) Discrete symmetries, 3) Time-independent perturbation theory.
16. Thu, Mar 18 JJS 5.3 Fine structure of atomic terms Relativistic corrections to the Hamiltonian of a hydrogenlike atom. Application of perturbation theory. Fine structure of atomic terms.
17. Tue, Mar 23 JJS 5.3 Zeeman effect. Lande and Paschen-Back cases. Perturbation theory II. Time-dependent case. Interaction representation.
18. Thu, Mar 25 JJS 5.5, 5.6 Homework 18 is given. Interaction representation. Example of a two-level system. Dyson series. Transition probabilities.
Tue, Mar 30 No classes, Spring Break.
Thu, Apr 1 No classes, Spring Break.
19. Tue, Apr 6 Measurements in quantum mechanics. Entanglement, quantum computing, etc.
20. Thu, Apr 8 JJS 5.6 Homework 19 is given. Time-dependent perturbation theory. Constant and harmonic perturbations. Fermi's Golden Rule.
21. Tue, Apr 13 JJS 5.8
EM Ch.7
Energy shift and decay width. Semiclassical (WKB) approximation. Quasiclassical approximation. Expansion in Planck's constant. Wave function and classical action. Criterion of quasiclassicity.
22. Thu, Apr 15 EM Ch.7 Homework 20 is given. Connection formulas. Bound states. Bohr-Sommerfeld quantization condition.
23. Tue, Apr 20 EM Ch.7 Double-well potential. Transmission through the barrier. Resonant transmission.
24. Thu, Apr 22 LL 52-53
DJG Ch.10
Homework 21 is given. Reflection above the barrier. The method of complex classical paths. Adiabatic approximation. Adiabatic theorem. Dynamic and Berry's phases.
25. Tue, Apr 27 DJG Ch.10
JJS 2.5
Berry's (geometrical) phase. Landau-Zener transitions. Path integrals. Path integral representation of transition amplitudes. Path integral for phase space trajectories. Feynmann path integral.
26. Thu, Apr 29 JJS 6.1-6.2 Homework 22 is given. Identical particles and spin. The permutation symmetry. Symmetrization postulate. Bosons and fermions. Spin-statistics theorem. Two-electron system. Spin triplet and spin singlet: orbital and spin functions. Exchange density and exchange interaction.
27. Tue, May 4 JJS 7.1-7.2 Introduction to scattering theory. Scattering problem. Differential and total scattering cross sections in classical mechanics. Scattering amplitude. The Lippmann-Schwinger equation. Green's function.
28. Thu, May 6 JJS 7.2-7.3
7.3, 7.5-7.6
The Born approximation. Example of Yukawa potential. Coulomb limit. Optical theorem. Scattering of slow particles. Method of partial waves and phase shifts.
Thu, May 13 FINAL EXAM: Room P-128, 11:15am-1:45pm The final is "closed books and notes".