# Experts in: Quantum mechanics

### HAMMAD, Fayçal

Professeur associé

### LEONELLI, Richard

Professeur titulaire

- Condensed matter: elecronic structure, electrical, magnetic, and optical properties
- Condensed matter physics
- Excitons and related phenomena
- Collective excitations in electronic structure of nanoscale materials
- Photoluminescence of III-V and II-VI semiconductors
- Optical properties of nanoscale materials and structures
- Optical properties of quantum wells
- Raman spectra of III-V and II-VI semiconductors
- Time resolved spectroscopy
- Nanoscale materials and structures: fabrication and characterization
- Quantum mechanics

When a semiconductor material absorbs a photon, an electron is excited into the conduction band, leaving a *hole *in the valence band. The Coulomb interaction between the electron and the hole generates a bound state called an *exciton*, which largely controls the optical properties of semiconductors. In addition, when the environment is structured on a nanometric scale, the optical response of the semiconductors is radically altered by *quantum* *confinement.*

My research program revolves around the dynamics of excitons when they are created in nanostructured environments, so as to describe how the energy is absorbed and redistributed as part of a representation in terms of collective excitations. Although the subject is fundamental in nature, it is closely related to the development of *excitonics*, an emergent field that aims to design and manufacture better optical devices for applications ranging from lighting to quantum computing.

### LEROY, Claude

Professeur titulaire

- Physics of elementary particles and fields
- Nuclear physics
- ATLAS experiment (LHC)
- Storage rings and colliders
- Dosimetry
- Standard-model Higgs bosons
- Accelerators
- Extensions of the Standard Model
- Dosimetry / exposure assessment
- Solid-state detectors
- Unified theories and models of strong and electroweak interactions
- Quantum mechanics
- Quantum statistical mechanics

The study of the physics of the Standard Model of elementary particles and beyond, as part of the high-energy ATLAS experiment using the Large Hadron Collider (LHC) at CERN. This includes research into and the study of the Higgs boson, supersymmetric particles and any new physics revealed by the high-energy collisions produced by the LHC. The study of the radiation field produced in the ATLAS detector and its spectral characteristics using the Medipix and Timepix silicon pixel detectors (ATLAS-MPX and ATLAS-TPX). These measurements of the radiation field in ATLAS at CERN concern the detection and identification of charged particles (electrons, positrons, protons, anti-protons, pions, kaons, alpha particles and heavier ions, etc.) and neutral particles (photons, neutrons, neutral pions and kaons, etc.). Luminosity measurement in the LHC using the ATLAS-MPX and ATLAS-TPX detectors and the van der Meer beam displacement method.

Measurement of the efficiency of detection and shape recognition of particles in silicon pixel detectors and heavy semiconductor pixel detectors (GaAs, CdTe) with the tandem accelerator at the Université de Montréal R.-J. A. Lévesque laboratory.

The use of Medipix and Timepix silicon pixel detectors with charged particles, X-rays and gamma rays for imaging applications (use of charge sharing between pixels) with submicron spatial resolutions. The measurement of radiation fields and their spectral characteristics using pixel detectors in medical physics experiments (including hadron therapy) and in space (development of pixel detector-based dosimeters for space missions and the International Space Station). The study of radiation damage and the improvement of radiation resistance of particle detectors exposed to high radiation levels (neutron and photon flux, in particular) in various particle accelerators covering a wide range of energy levels and in nuclear reactors.

The preparation of a program for improving the detection capacity (in particular new generations of pixel detectors) of the ATLAS detector of the LHC at CERN and the improved LHC (SLHC), with higher collision energy and greater luminosity and in future colliders.

### MACKENZIE, Richard

Professeur titulaire

- Physics of elementary particles and fields
- Mathematical methods in physics
- Fractional statistics sytems (anyons, etc.)
- Theory of quantized fields
- Quantum mechanics
- Solitons
- Symmetry and conservation laws
- Spontaneous breaking of gauge symmetries
- Classical and semiclassical techniques in gauge field theories
- Extended classical solutions, cosmic strings, domains walls, textures
- Semiclassical theories and applications of quantum mechanics
- Decoherence, open systems, quantum statistical methods

Theoretical particle physics; quantum field theory and applications in particle physics, cosmology, condensed matter physics, etc. Semiclassical methods, topology in field theory, solitons, instantons. Quantum information.

### VINET, Luc

Directeur général, Professeur titulaire

- Mathematical methods in physics
- Algebraic structures
- Theory of quantized fields
- Quantum information
- Quantum mechanics
- Symmetry and conservation laws
- Integrable systems
- Random process

My research focuses on finding precise solutions to physics models. I work on designing systems for the perfect transfer of quantum information. I study the (random) quantum walks used in the development of quantum calculation algorithms. I examine the asymmetrical exclusion processes that apply in a large number of fields like biopolymerization and traffic-flow problems. My research also deals with stochastic processes used in genetic modelling. A large proportion of my work is devoted to integrable or superintegrable systems, so called because they have many conservation laws. They are important in theoretical terms and have many applications. The methodology underlying my research is based in part on the study of symmetries. I am also working to develop their mathematical description in terms of algebraic structures and orthogonal polynomials and special functions.