The QMat Student Symposia are events organized at the end of each academic year by QMat Students at the Faculty of Physics and Engineering of Strasbourg in coordination with the GeQS group and the Tutoring Division of the ARIANE. Schedules and slides of past symposiums can be found on this page. The schedule of the next symposium is updated regularly.

2025 Symposium on Quantum Sciences

3 June 2025

Salle 103, Institut de Physique

10h15: Welcome of the students

Loris Delafosse

10h30: Wigner Quantum Mechanics: A phase-space formalism

Maxence Pandini

Multiple formalisms of quantum mechanics have been developed during the last century to overcome difficulties as in many-body systems. One of the most appealing formalism for physicists would be one mapping quantum mechanics to the usual phase-space of classical mechanics, this is the aim of the formalism introduced by Eugene Wigner in the 1930s. He introduced a quasi-probability distribution in phase-space known as the Wigner function that is exactly equivalent to the density matrix and describes entirely quantum mechanics. We will introduce this formalism and apply it to simple models. Current use of this formalism in modern physics will be also presented (quantum tomography, many-body dynamics).

Slides

13h30: Quantization and Path Integrals

Loris Delafosse

The path integral, developed by Feynman in the 1940s, is one of the best-known and most widely used formulations of quantum mechanics. It owes its success to the elegant physical interpretation it provides for quantization, and to the fact that it describes both non-relativistic quantum mechanics and quantum field theory. However, despite this great success, path integrals usually happen to be ill defined as mathematical objects. This seminar aims at presenting the challenge of quantization, the way it is tackled by path integration, and the issues faced by this formalism.

Slides

15h15: The subtle art of counting holes

Loris Delafosse

The notion of singularity is omnipresent in physics. Whether we're interested in crystalline impurities, magnetic monopoles or cosmic strings, the study of "holes" is of paramount importance. But what is a hole? How do you find one? We want to give here some physical intuition behind the concepts of algebraic topology.

2024 GeQS Seminar on Quantum Sciences

4 June 2024

Salle 103, Institut de Physique

10h30: Welcome and presentation

10h40: Semi-classical approaches in quantum mechanics

Loris Delafosse

Before the establishment of quantum mechanics, physicists attempted to modify the paradigm of classical mechanics to include the quantization phenomena discovered by experimentalists. This “old quantum theory” led to models still in use today that simplify the mathematical treatment of quantum effects.
 
Slides

14h00: Spinors, geometry and space-time

Loris Delafosse

Giving a correct geometric interpretation to the mathematical concepts of physics can serve as a guide for developing and understanding physical theories, particularly in quantum mechanics (notoriously difficult to understand) and general relativity (where geometry plays a central role). These considerations led to the development of twistor theory, which generates spacetime from spinors representing light rays.

Slides

16h30: Introduction to the Higgs mechanism

Simon Beaudoin

The Standard Model of particle physics predicts massless gauge bosons, which experiment refutes for the W and Z bosons. Brout, Englert, and Higgs have devised a mechanism that is currently the best resolution of this inconsistency. The (recent!) detection of the Higgs boson was a major step forward in our understanding of the concept of mass, but introduces new unresolved questions in the Standard Model.

Slides