# Experts in: Quantum mechanics

### DHARMA-WARDANA, Chandre

Professeur associé

- Quantum mechanics
- Quantum statistical mechanics
- Raman spectra of III-V and II-VI semiconductors
- Electron-phonon interactions
- Optical properties of nanoscale materials and structures
- Thermal properties of small particles, nanocrystals, nanotubes and other related systems
- Graphene

Professor Dharma-wardana has worked on a wide variety of scientific topics, where the unifying theme is the application of the quantum theory, usually to many-body problems. His work focused on quantum theory, statistical mechanics, and solid state physicsassociated with Raman scattering, energy-relaxation and phonons in nanostructures, quantum Hall effect, the physics of nanotubes and graphene. He worked on a variety of topics such as surface passivisation, quantum dots, organic light-emitting diodes and related nanostructures, energy-relaxation etc., in collaboration with researchers at the NRC, Universities or research institutions in Montreal, Toronto, British Columbia, Livermore, Los Alamos and Paris. A main area of Prof. Dharma-wardana's research has been in many-body theory and plasma physics, often in collaboration with François Perrot of the French Atomic Energy commission. The neutral-pseudo atom model (NPA) for warm dense matter is one of their main contributions of great practical value where finite-temperature density functional theory has been used to formulate a rigorous quantum mechanical approach to hot ionized matter. Subsequently, the construction of the classical-map scheme for quantum systems is a ground-breaking work, leading to the formulation of the classical-map hyper-netted chain method (CHNC). This method has led to a new approach for the evaluation of properties of Fermi liquids and warm-dense matter.

His previous work on the density-functional theory of dense plasmas is now well-established in the NPA model. It has led to the development of methods for the first-principles evaluation of the equation of state, and the transport properties of dense plasmas. His contributions to the energy-relaxation of hot electrons in semiconductors and also in plasmas,have presented a new direction in the theory of non-equilibrium states of two-temperature charged fluids. His paper elucidating the unusual thermal conductivity of clathrates still attracts many citations. His contributions to surface science (e.g. reconstruction of the sulphur-passivated InP surface), nanotechnology, phonons in semiconductor structures, quasi-periodic systems etc., are well known and are contained in over 200 research publications. Dharma-wardana currently serves as a principal research scientist at the National Research Council of Canada, and is a professor of theoretical physics at the Université de Montréal. His most recent book on physics is entitled *A Physicist's View of Matter and Mind*, published in 2013 by World Scientific.

### 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, 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.