Angular Momentum in Quantum Mechanics
Prof. J. C. Baird
1996 Lectures are below

1996 Lectures in Streaming Audio below

October 11, 1995

Angular Momentum


Angular Momentum A

Angular Momentum B

Angular Momentum C

Angular Momentum D

Angular Momentum E

Angular Momentum Eigenvalues

October 22, 1996

Lecture 10-22-96: Angular Momentum in Quantum Mechanics

Overheads: Angular Momentum

Torque on an Angular Momentum

Conservation of Angular Momentum

Heisenberg Equation of Motion

J = L + S

Connection between Angular Momentum and Rotations

Rotational Invariance of the Hamiltonian

Taylor Expansion about the Rotated Coordinate and the Rotation Operator

Commutators

Spherical Polar Coordinates

Total Angular Momentum in Spherical Polar Coordinates

Matrix Elements in Hilbert Space

Matrix Elements Continued

Matrix Elements C

Raising and Lowering Operators

Operator Algebra

Angular Momentum Eigenvalue Relationships

Angular Momentum Quantum Numbers

M values

October 13, 1995

Normalization of Ket

Matrix Elements of Angular Momentum Components

Electron in an Inhomogeneous Field

Spin Angular Momentum in a Magnetic Field

Euler Angles, Rigid Rotors

Reversed Angular Momentum

October 24, 1996

Lecture 10-24-96: Angular Momentum - Normalization and Matrix Elements. Application of Spin in a Magnetic Field

Overheads: Matrix Elements; Electron in Field; Simple Rotor

Normalization of State J + 1

Normalization

Normalization and Matrix Elements K

Matrix Elements

Atom in an Inhomogeneous Field: Stern Gerlach Effect

Force on Atom in an Inhomogeneous Field

Energy of Electron Magnetic Moment in a Magnetic Field

Arbitrary Orientation of the External Magnetic Field

Hamiltonian Matrix and Energies of Electron Magnetic Moment in an Arbitrarliy Orientated Magnetic Field

October 28, 1996

Lecture 10-28-96: Angular Momentum - Rigid Body Rotation. Euler Angles

Diatomic Rotor A

Diatomic Rotor B

Rotation of a Rigid Body

Rotation of a Rigid Body Continued

Orientation of a Rigid Body in Space

Euler Angles

Direction Cosines

Quantum Numbers for a Symmetric Top Rotor

Rotation of a Symmetric Top

Reversed Angular Momentum

October 16, 1995

Molecular Rotation A

Molecular Rotation B

Molecular Rotation C

Molecular Rotation D

Molecular Rotation E

Molecular Rotation F

Molecular Rotation G

Molecular Rotation H

Overheads: Molecular Rotation

General Rigid Rotor Hamiltonian

Moments of Inertia

Inertial Matrix

Diagonalization of Inertial Matrix

Simple Rotational Hamiltonian

Diatomic Rotor & Spherical Top

Symmetric Top

Asymmetric Top

A Simple Perturbed Diatomic Rotor

Matrix Elements in the Angular Momentum Representation

Eigenvalues

Eigenfunctions A

Eigenfunctions: Normalization

Eigenfunctions: First Row of Similarity Transformation

Eigenfunctions: Normalized First Row

Eigenfunctions: Second Row of Matrix

Eigenfunctions: Normalized Transformation

Eigenfunctions: Third Eigenvalue

Complete Similarity Transformation

October 18, 1995

Coupling of Two Angular Momenta - Coupled Scheme

Coupled Scheme Continued B

Coupled Scheme Continued C

Coupled Scheme Continued D

Uncoupled Representation

Uncoupled Representation Continued F

October 30, 1996

Lecture 10-30-96: Coupling of Two Angular Momenta - Coupled Representation and the Uncoupled Representation

Overheads: Coupling of Two Angular Momenta

Addition of Two Angular Momenta

Addition of Two Angular Momenta Continued

Coupled Angular Momenta Precessing in a Field

Commutators

Case 1: Coupled Scheme

Case 1: Hamiltonian and Matrix Elements

Case 2: Precessing Angular Momenta

Case 2: Uncoupled Representation

October 20, 1995

Relation between Coupling Schemes

Vector or Clebsch-Gordon Coefficients

Wigner 3j Symbols

Calculaton of Clebsch-Gordon Coefficients

Symmetries and 3-j Symbols

Wigner 3-j Symbols Continued

Wigner 3-j Symbols Continued

November 5, 1996

Lecture 11-5-96: Angular Momentum - Coupled and Uncoupled Representations - Wigner 3j Symbols

Overheads: Relation between the Coupled and the Uncoupled Representations

Relationship between Coupling Schemes

Totally Stretched Case

Totally Stretched Case B

Evaluation of Clebsch-Gordon Coefficients

Expansion of Coupled Wave Function in terms of the Uncoupled Representation & Clebsch-Gordon Coefficients

Jz Operating on the Totally Stretched Ket |J,j1 + j2;j1,j2)

J^2 Operating on the Totally Stretched Ket |J,j1 + j2;j1,j2)

The Totally Stretched Ket less 1 |J,j1 + j2 -1;j1,j2)

Raising Operator on |J,j1 + j2 -1;j1,j2)

Clebsch-Gordon Coefficient from two Simultaneous Equations

Wigner 3-j Symbols Defined in terms of Clebsch-Gordon Coefficients

Definition of Wigner 3j Symbol

Properties of the Wigner 3j Symbol

More Properties of the Wigner 3j Symbol

Formulas for some Wigner 3j Symbol

A Sum Rule

October 23, 1995

The Wigner-Eckart Theorem

Introduction to the Wigner-Eckart Theorem

Wigner Eckart Theorem

Spherical Tensors and the Wigner Eckart Theorem

Rotations of a Spherical Tensor

Illustration of Wigner-Eckart Theorem applied to an Electronic Wave Function

Mapping of a Tensor from one Coordinate System to another

November 7, 1996

The Wigner-Eckart Theorem

Lecture 11-7-96: Wigner Eckart Theorem

Overheads: Spherical Tensors and the Wigner-Eckart Theorem

Wigner-Eckart Theorem Illustrated using Spherical Harmonics

Wigner-Eckart Theorem using Spherical Harmonics cont.

Spherical Tensor Notation for Cartesian Vectors in Spherical Polar Coordinates

Comparison with Spherical Harmonics

Rotation of a Spherical Harmonic

Rotation of a Spherical Tensor

General Commutation Relations for Spherical Tensors

Commutators of a Vector

A Commutator leading to the Wigner-Eckart Theorem

The Wigner-Eckart Theorem

Double Bar Matrix Elements for the Spherical Harmonics

Double Bar Matrix Elements continued

October 25, 1995

Spherical Tensors and Application to the Stark Effect in a Symmetric Top Rotor

Spherical Tensors and Applications(ram file)

Spherical Tensors and Applications (2.8MB download!)

Spherical Tensors and Applications A

Spherical Tensors Cont. B

Symmetric Top in an Electric Field

Commutation Relations between Spherical Tensors and Angular Momentum Operators

Wigner-Eckart Theorem Derived

October 27, 1995

The Quantum Mechanics of the Zeeman Effect on a Spin-Orbit Coupled Atom: Coupled and Uncoupled Representations

Introduction to the Zeeman Effect on an Atom with Spin-Orbit Coupling

Zeeman Effect - Coupled Representation

Coupled Representation Continued

Wigner-Eckart Theorem Applied to the Coupled Representation for the Zeeman Effect

Uncoupled Representation for the Zeeman Effect

Overheads: The Zeeman Effect on a Spin-Orbit Coupled Atom

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