Seminar by Dr. Oleg Rubel

Event Date: 
Wednesday, May 21, 2014 - 10:00am to 11:00am EDT
Event Location: 
CB 4058
Event Contact Name: 
Dr. Mark Gallagher
Event Contact Phone: 

The Department of Physics presents a seminar by:

Dr. Oleg Rubel
Scientist, Thunder Bay Regional Research Institute
Adjunct Professor, Physics, Lakehead University

Band structure of disordered solids: from localization to high-mobility Kane fermions

Supercells are often used in ab initio calculation in order to model compound alloys, surfaces and defects. One of the main challenges of supercell electronic structure calculations is to recover Bloch character of electronic eigenstates perturbed by a disorder. Here we apply the spectral weight approach to unfolding of the electronic structure of group III-V and II-VI semiconductor solid solutions. The illustrative examples include: formation of localized donor-like states in dilute GaP:N and associated enhancement of its optical activity, direct observation of the valence band anicrossing in dilute GaAs:Bi, and a topological band crossover in ternary (HgCd)Te alloy accompanied by emergence of high-mobility Kane fermions. The analysis facilitates interpretation of optical and transport characteristics of alloys that are otherwise "obscure" in traditional first-principle supercell calculations.

 WEDNESDAY, MAY 21, 2014
10:00 a.m.
CB 4058

click here for poster

Department of Physics Presents The Canadian Association of Physicists (CAP) Lecture Series: Speaker - Dr. Cliff Burgess

Event Date: 
Tuesday, January 14, 2014 - 1:30pm to 2:30pm EST
Event Location: 
BB 1021
Event Contact Phone: 
(807) 343-8461


The Canadian Association of Physicists (CAP) Lectures Series


McMaster University / Perimeter Institute

"The Dog that Didn't Bark:  The  Cosmological Constant Problem and
the Puzzle of Dark Energy"

Tuesday, JANUARY 14, 2014
at 1:30 p.m.
in BB 1021
click here for poster

The (‘old’) Cosmological Constant Problem, which asks why the vacuum zero-point energy appears not to gravitate, was a theoretical thorn in our collective sides even before the Dark Energy was discovered. This talk reviews why it is regarded to be a problem, and argues that its solution is likely to be the biggest clue we have about the nature of Dark Energy. A set of minimal criteria are formulated against which proposed solutions to the problem can be judged, and most proposals found to fail. Finally I argue why I believe that a solution to the Cosmological Constant Problem exists and is telling us why the LHC should not see superpartners for ordinary particles, even though it also implies that supersymmetry must exist and be important at low energies. 

Short biography

Cliff Burgess was born in Manitoba and was raised in various places around Western Canada, Ontario and Europe. He received his B.Sc. in a co-op programme, with a joint honours in Physics and Applied Math from the University of Waterloo. He did his doctoral work in Theoretical Particle Physics at the University of Texas in Austin under the supervision of Steven Weinberg. After doing a short postdoctoral stint at the Institute for Advanced Study in Princeton, in 1987 he joined the faculty at McGill University, where he was made James McGill Professor in 2003. He is presently a professor with McMaster University’s department of Physics and Astronomy and is an Associate Faculty Member at Perimeter Institute for Theoretical Physics. He has spent sabbatical years with the Institute for Advanced Study in Princeton as well as the University of Neuchatel and CERN in Switzerland. Cliff was a Killam Fellow from 2005 – 2007 and elected a fellow of the Royal Society of Canada in 2008. He received the Canadian Association of Physicists/Centre de Recherches Mathematiques (CAP-CRM) prize for theoretical physics in 2010.

PHYSICS Department - PHYS 5411 Student Final Presentation

Event Date: 
Wednesday, December 18, 2013 - 9:00am to 9:30am EST
Event Location: 
CB 4058

Presents a  PHYS 5411- Topics in Computational Physics and Material Science
 Final Presentation by: 

Ayman Alahmar
PhD Student in Chemistry and Material Science program

"Towards Accurate Results in Computational Material Science"

Duration: 20 mins presentation + questions

The presentation is a final part of a student project work performed in the framework of the course PHYS-5411 "Topics in Computational Physics and Material Science".