Event Time: Thursday, September 19, 2019 | 2:00 pm - 3:00 pm
Event Location:
TRIUMF Auditorium
Add to Calendar 2019-09-19T14:00:00 2019-09-19T15:00:00 Challenges in gravitational wave astronomy Event Information: Advanced LIGO and Advanced Virgo are currently in the middle of their third observing run, and releasing open public event alerts for the first time. The LIGO-Virgo collaboration has issued 28 un-retracted candidate event alerts as of September 11th, 2019, potentially adding dozens more known compact binary object mergers to the eleven confident detections from the first two Advanced-era observing runs. I'll give an overview of the process of detecting, characterizing, and assessing the significance of gravitational wave signals registered in Advanced LIGO data. I’ll review novel results from LIGO-Virgo to date, and the challenges of extracting interesting new physics from noisy detector data. Finally, I'll summarize the roadmap to future gravitational wave detectors on Earth and in space. Event Location: TRIUMF Auditorium
Event Time: Monday, September 23, 2019 | 2:00 pm - 3:00 pm
Event Location:
TRIUMF Auditorium
Add to Calendar 2019-09-23T14:00:00 2019-09-23T15:00:00 Half Life – the divided life of Bruno Pontecorvo, physicist and spy Event Location: TRIUMF Auditorium
Event Time: Thursday, October 3, 2019 | 2:00 pm - 3:00 pm
Event Location:
TRIUMF Auditorium
Add to Calendar 2019-10-03T14:00:00 2019-10-03T15:00:00 Identification and control of domain wall patterning in spinel ferrimagnets Event Information: Spinel antiferromagnets have long been at the center of research into strong spin-lattice coupling and orbital effects. Among other properties, these materials frequently demonstrate concomitant magnetic and structural phase transitions, heightened magneto-elastic or dielectric response functions, and low-temperature multiferroism. There is very little agreement on the microscopic picture to be associated with these effects, but recent work has shown that mesoscale inhomogeneity can play a key role in raising the susceptibilities of complex materials to external perturbations. In this talk, I will be discussing recent work at the University of Illinois which establishes the importance of mesoscale heterogeneity in determining bulk magnetic properties of spinel ferrimagnets Mn3O4 and MnV2O4. This will first include a review of Raman and x-ray scattering results which reveal the existence of low-temperature magnetostructural transitions and magnetic force microscopy data which show the existence of stripe-like magnetic domains, before turning to our more recent neutron scattering and muon spin rotation (muSR) measurements. Our muSR work associates the emergence of stripe-like domains in Mn3O4 with a real space separation into magnetically ordered and disordered volumes, and further shows that the ordering fraction can be grown with the application of moderate-sized fields. With small angle neutron scattering, we observe Bragg signatures of domain wall order in the bulk of both materials, with wall separations on the ~100nm scale. Lastly, I will present data that demonstrates how domain wall motion can be used to drive these systems out of their low-temperature ferrimagnetic states, with an Hc which is highly sensitive to the applied field direction. I will correlate these results from microscopic probes to our recent investigation into non-equilibrium effects in the bulk magnetization, and discuss in the context of “colossal” control of magnetic properties of real materials. Acknowledgments: Research was supported by the National Science Foundation under Grant NSF DMR 1455264. Event Location: TRIUMF Auditorium
Event Time: Wednesday, October 16, 2019 | 2:00 pm - 3:00 pm
Event Location:
TRIUMF Auditorium
Add to Calendar 2019-10-16T14:00:00 2019-10-16T15:00:00 A brief introduction to glasses Event Information: Glassy materials and they way glasses are formed from liquids is an active area of both fundamental and applied research. While it is relatively easy to describe low density disordered materials (gas) and high density ordered materials (crystals), high density disordered materials - especially glassy solids - remains a difficult and unresolved problem. Of particular interest is the concept of an ideal glass, and if such a thing does exist how can it be realised? I will discuss characteristics of glasses and glass forming materials, some simple ways of thinking of the dynamics of these materials, the properties of these materials in nanoscale environments, and some very recent tantalizing observation that bring us close to the realizations of ideal glasses. The samples, which can be prepared in the lab in a few hours, have properties similar to those of samples that have been allowed to age for many thousands, or even millions of years.   Event Location: TRIUMF Auditorium