Course program
[1] Introduction: crisis of classical mechanics and birth of Quantum Mechanics
-Matter-wave duality, double slit experiment, wave function as a probability amplitude.
[2] Axiomatic definition of Quantum Mechanics
- Hilbert space, self-adjoint operators, Dirac formalism, change of basis;
-Uncertainty relation. Wave functions with minimum product of uncertainty between position and momentum
-Common basis of commuting observables. Complete set of commuting observables.
- Expectation values of observables, measurement of observables: collapse of the wave function (Copenhagen interpretation)
- Position and momentum operators, continuous spectrum of eigenvalues and non-normalizable states, eigenfunctions of the position operator; position and momentum representations; position operator in momentum representation
- Symmetries in QM and in Hamiltonian mechanics, generators and conserved quantities, Noether theorem
- Momentum as generator of spatial translations. Canonical commutation rules, commutator of position and momentum operators. Spatial inversion and parity.
- Hamiltonian as generator of time evolution. Time-dependent Schroedinger equation, Heisenberg dynamical picture, Ehrenfest theorem.
- Angular momentum as generator of rotations, commutation rules of angular momentum. Symmetry groups and their properties.
[3] Problems in 1 dimension
- Free particle: plane waves and wave packets, energy spectrum. Degeneracy theorem.
- Free particle on a segment. Square potential well, discrete and continuous energy spectrum. Non-degeneracy theorem.
- General properties of the solutions of Schroedinger equation in 1-dimension. Quantization of energy levels.
- Harmonic oscillator: raising and lowering operators, energy eigenvalues and eigenfunctions. Coherent states.
- Scatterings in 1 dimension, reflection and transmission coefficients, tunnel effect. Probability conservation, continuity equation.
[4] Time-independent perturbation theory (Rayleigh-Schroedinger)
- Theory for discrete and non-degenerate spectra, extension to the degenerate case. Validity of the approximation.
[5] 3-dimensional systems and Theory of Angular Momentum
- Tensor product of vectorial spaces. Separation of variables. Particle in a box. 3-dimensional harmonic oscillator. Two-body problem in QM: center-of-mass and relative motions.
- Rotationally invariant systems, radial equation. Algebraic method for the computation of the eigenvalues of angular momentum. Orbital angular momentum, spherical harmonics. 3-dimensional harmonic oscillator.
- Coulomb potential and hydrogen atom: discrete energy eigenvalues and eigenfunctions.
- Spin as an internal degree of freedom. Pauli matrices, spin rotations.
- Charged particle in external electromagnetic field. Dipole moment, precession of angular momentum, Pauli Hamiltonian.
- Stern e Gerlach experiment and measurement of the electron spin
- Composition of angular momenta: eigenstates of total angular momentum and Clebsch-Gordan coefficients
- Gauge invariance
[6] Identical Particles.
- Particle exchange operator and its action on the state vector. Bosons and fermions. Hilbert space for identical particles and its properties.
Prerequisites
Fundamental knowledge of the following subjects: linear algebra, vectorial spaces and operators, Fourier transform, mechanics and electrodynamics, Maxwell equations and electromagnetic waves, special relativity, lagrangian and Hamiltonian formalism, equations of motion and their invariance, conserved quantities.
Books
S. Weinberg, Lectures on Quantum Mechanics (seconda edizione), Cambridge Univ. Press
L. Picasso, Lezioni di Meccanica Quantistica (seconda edizione), edizioni ETS
S. Forte, L. Rottoli, Fisica Quantistica, Zanichelli editore
R. Shankar, Principles of Quantum Mechanics (second edition), Springer
D. Griffiths, Introduction to Quantum Mechanics, Addison-Wesley ed.
Teaching mode
Lectures and training sessions in classroom.
Frequency
Lectures and training sessions in classroom.
Exam mode
Written and oral exam.
Bibliography
S. Weinberg, Lectures on Quantum Mechanics (seconda edizione), Cambridge Univ. Press
L. Picasso, Lezioni di Meccanica Quantistica (seconda edizione), edizioni ETS
S. Forte, L. Rottoli, Fisica Quantistica, Zanichelli editore
R. Shankar, Principles of Quantum Mechanics (second edition), Springer
D. Griffiths, Introduction to Quantum Mechanics, Addison-Wesley ed.
Lesson mode
Lectures and training sessions in classroom.