Vector spaces and operators

Quantum Mechanics (Winter, 2012)

Lecture Playlist

  1. Introduction to quantum mechanics

  2. The basic logic of quantum mechanics

  3. Vector spaces and operators

  4. Time evolution of a quantum system

  5. Uncertainty, unitary evolution, and the Schrödinger equation

  6. Entanglement

  7. Entanglement and the nature of reality

  8. Particles moving in one dimension and their operators

  9. Fourier analysis applied to quantum mechanics and the uncertainty principle

  10. The uncertainty principle and classical analogs

January 23, 2012

Professor Susskind elaborates on the abstract mathematics of vector spaces by introducing the concepts of basis vectors, linear combinations of vector states, and matrix algebra as it applies to vector spaces.  He then introduces linear operators and bra-ket notation, and presents Hermitian operators as a special class of operators that represent observables.  Eigenvectors of Hermitian operators represent orthogonal vector states, and their eigenvalues are the values of the observable.

Professor Susskind then applies these concepts to the single spin system that we studied in the last lecture, and introduces the Pauli matrices as the Hermitian operators representing the three spin axis directions.

Topics: 
  • Vector spaces and state vectors
  • Hermitian operators and observables
  • Eigenvectors and eigenvalues
  • Normalization and phase factors
  • Operators for a single spin system
  • Pauli matrices
References