Foundations of Quantum Mechanics

A.Y. 2022/2023
6
Max ECTS
42
Overall hours
SSD
FIS/02 FIS/03
Language
Italian
Learning objectives
The main goal of the course is to provide the students with the key theoretical tools to understand quantum mechanics as a probability theory, inherently different from the classical one.
After introducing the statistical formulation of quantum mechanics, we will investigate the most relevant features characterizing such a description. We will first introduce the Bell's inequalities and the related notion of non-locality, and then we will study contextuality, from the Kochen-Specker's theorem to the more recent developments. Moreover, we will study the possibility to detect the quantum nature of a system evolving in time, through the notion of measurement invasiveness and the Leggett-Garg's inequalities.
Expected learning outcomes
At the end of the course the student will be able to:
1. Use the mathematical formalism needed to provide a general description of quantum mechanics as a probability theory
2. Derive the Bell's inequality, Tsirelson's inequality and Fine's theorem in the case of two observers measuring two observables each
3. Detect the key role of (non-)locality and (non-)existence of the joint probability distribution in discriminating between the classical and quantum theories of probability
4. Distinguish different notions of non-contextuality and use them to derive the Kochen-Specker's theorem and noncontextuality inequalities
5. Present the main experimental tests of quantum contextuality, along with the most relevant applications
6. Describe and quantify the invasiveness of a quantum measurement, compare it with the notion of contextuality and use it to derive the Leggett-Garg's inequalities
7. Characterize the conditions for classical simulability of multi-time probabilities and discuss the possibility to exploit them for experimental tests of non-classicality
Single course

This course cannot be attended as a single course. Please check our list of single courses to find the ones available for enrolment.

Course syllabus and organization

Single session

Responsible
Lesson period
Second semester
Course syllabus
1. Quantum states and observables
· Statistical operators
· Gleason's theorem
· Dispersion-free states
· Positive operator-valued measure (POVM)
· Compatible observables
2. Bell's inequalities
· Non-locality
· Derivation of the CHSH Bell's inequality
· Tsirelson's inequality
· Toward contextuality: Fine's theorem
· Hidden-variable models (introduction)
3. Quantum mechanics as a contextual theory
· Kochen-Specker's theorem: original formulation and proof in a simple scenario
· Recent developments on contextuality: noncontextuality inequalities and operational definitions
· Experimental tests of quantum contextuality
· Contextuality as quantum resource: comparison with other notions (coherence and entanglement) and example applications
4. Leggett-Garg's inequalities
· Invasiveness of measurements and contextuality in time
· Derivation of Leggett-Garg's inequalities from the Kolmogorov consistency conditions and comparison with Bell's inequalities
· Classical simulability of multi-time probabilities
· Experimental tests
Prerequisites for admission
The course is structured to be self-consistent and assumes that students have the basics notions of the classical theory of probability and quantum mechanics.
Teaching methods
The adopted didactic method is based on lectures with the use of the blackboard, including both theoretical explanations and exercises.
Teaching Resources
· Lecture notes (available on the online platform Ariel)
· T. Heinosaari e M. Ziman, The Mathematical Language of Quantum Theory, Cambridge, 2012
· C. Emary,
Assessment methods and Criteria
The exam consists of an oral interview (lasting from 45 to 75 minutes) in which both the knowledge acquired during the lectures and the ability to deal with problems related to the topics discussed in class will be assessed.
FIS/02 - THEORETICAL PHYSICS, MATHEMATICAL MODELS AND METHODS
FIS/03 - PHYSICS OF MATTER
Lessons: 42 hours
Professor: Smirne Andrea
Professor(s)
Reception:
On appointment (also remotely on Zoom, if needed)
5th floor, building LITA room A/5/C4