Events List for the Academic Year

Event Time: Tuesday, May 24, 2022 | 2:00 pm - 5:00 pm
Event Location:
Henn 318 & https://cern.zoom.us/j/63497174616?pwd=UDNRN1JLSUNVemd0SnJhalVuYlcvQT09
Add to Calendar 2022-05-24T14:00:00 2022-05-24T17:00:00 PhD defense Robin Hayes Event Information: The Standard Model (SM) is the governing theory of particle physics. Although its predictions are in excellent agreement with experimental observations, it does not provide a full picture of the physical universe. The Higgs boson is the SM's most recently-discovered particle and a crucial ingredient of the theory. Measuring any deviation between its observed and expected properties could pave the way toward a more complete theory.  This thesis describes a study of the Higgs boson using proton-proton collisions at the Large Hadron Collider. The collision data was collected between 2015 and 2018 by the ATLAS detector. This research identifies the Higgs boson using its decay to two W bosons, H->WW*. It examines Higgs boson production via gluon fusion and vector boson fusion, making it sensitive to the Higgs boson's interactions with both heavy quarks and vector bosons. It results in the first observation of vector boson fusion production followed by H->WW* decay and measurements of Higgs boson cross-sections inclusively and across various kinematic regions. The measurements are made with unprecedented precision in this decay channel, and are compatible with the SM prediction. Event Location: Henn 318 & https://cern.zoom.us/j/63497174616?pwd=UDNRN1JLSUNVemd0SnJhalVuYlcvQT09
Event Time: Thursday, May 12, 2022 | 2:00 pm - 5:00 pm
Event Location:
Zoom: https://ubc.zoom.us/j/61164285940?pwd=QWFiV0JZT3VwTXVacnc4SEh5UVErdz09. Password: 053582.
Add to Calendar 2022-05-12T14:00:00 2022-05-12T17:00:00 Apocalyptic quantum gravity Event Information: Black holes are regions of spacetime from which nothing can escape. This is already strange, but more puzzling is the fact that, over time, quantum mechanics causes black holes to leak energy and disappear. What happens to the objects that fell inside? The unitarity of quantum mechanics suggests one answer, and computations in semiclassical gravity another. To determine which is correct, we need to understand how quantum and gravitational effects interact.   This thesis develops techniques to peer inside black holes and track the flow of information. We exploit and extend the AdS/CFT correspondence, an approach to quantum gravity in which data at the boundary of spacetime is related to geometric structure in the bulk. The basic strategy is to make highly symmetric incisions along the boundary, dual to surfaces in the bulk called end-of-the-world (ETW) branes, since they literally terminate spacetime. In some cases, these branes can reach inside the black hole interior and teach us about what happens there. We also carefully study the quantum mechanics of ETW branes and find that the scalpels needed to make the incisions are finely tuned, hidden like the needle in a proverbial haystack of consistent microscopic boundary conditions. Event Location: Zoom: https://ubc.zoom.us/j/61164285940?pwd=QWFiV0JZT3VwTXVacnc4SEh5UVErdz09. Password: 053582.
Event Time: Friday, May 6, 2022 | 12:00 pm - 2:30 pm
Event Location:
University of Winnipeg or Watch live! (See webinar registration link below)
Add to Calendar 2022-05-06T12:00:00 2022-05-06T14:30:00 2022 Western Regional Three-Minute Thesis Competition: PHAS Graduate student Emilie Carpentier represents UBC Event Information: 2022 Western Regional Three-Minute Thesis Competition is being hosted by the University of Winnipeg on May 6, 2022 from 2:00-4:30 pm (CST) Seventeen graduate schools across western Canada are sending their local Three-Minute Thesis Competition winners to compete in the 2022 Western Regional Competition! Originally developed by the University of Queensland, the Three-Minute Thesis is an annual research communication competition challenging graduate students to communicate their scholarly research and its significance in three minutes or less. Join us in supporting Emilie and other finalists in the Regionals! Register for the livestream webinar this Friday, May 6th from 2:00-4:30pm CST (12:00-2:30pm PDT).  See the full 2022 3MT competition schedule here: Schedule 2022 | Three Minute Thesis (3MT) (ubc.ca)   Event Location: University of Winnipeg or Watch live! (See webinar registration link below)
Event Time: Thursday, April 28, 2022 | 4:00 pm - 5:00 pm
Event Location:
Hennings 201 (and via zoom)
Add to Calendar 2022-04-28T16:00:00 2022-04-28T17:00:00 EVENT CANCELLED: Equity and Inclusion Survey Town Hall Event Information: -- This event is cancelled for Thursday, April 28th --   In 2020, the Physics and Astronomy (PHAS) Equity and Inclusion Committee at UBC conducted a Departmental Climate Survey to identify current issues in the department and to provide recommendations to create a more welcoming workplace. The responses to this survey strengthen our understanding of the demographics and diversity of experiences in PHAS, which are key to determining how we can make the Department more inclusive. In the following years, various new projects have been started to address the issues highlighted by the survey results. This colloquium will feature a short presentation of the survey results from Dept. Head Colin Gay and Deputy Dept. Head Ingrid Stairs, followed by a town hall-style discussion focused on the future directions our department will be making in order to promote a more inclusive environment. The survey report is now available on the PHAS internal site (link here), and we encourage everyone to review the findings and recommendations. In the coming weeks and months, the Equity and Inclusion Committee will also be hosting a series of additional discussion forums with various groups (grads, staff, etc.) in the department. These will provide opportunities, in addition to the town hall event this Thursday, for others to share their thoughts and experiences in smaller settings. Event Location: Hennings 201 (and via zoom)
Event Time: Thursday, April 28, 2022 | 10:00 am - 12:00 pm
Event Location:
zoom : https://ubc.zoom.us/j/63707269353?pwd=YnZKMzd4K0NKWGtESUJSS2JXNGU5Zz09 Passcode: 486279
Add to Calendar 2022-04-28T10:00:00 2022-04-28T12:00:00 PhD Defense: Electron-phonon coupling in the time domain: TR-ARPES studies by a cavity-based XUV laser Event Information: Quantum materials manifest exciting macroscopic electronic properties that emerge from microscopic electron interactions -- such as those between the electron and the lattice. Extensive research effort has been dedicated to understanding the physics of these materials; among these, angle-resolved photoemission spectroscopy (ARPES) has the unique capability of taking ``photos" of the electronic band structure. This band structure is a fingerprint of the electronic properties of each material and encodes microscopic electron interactions. By combining ARPES with an ultrafast laser source, we can turn “photos" of the electronic band structure into “movies" and study how electrons respond to external perturbation, such as a short pulse of light. This technique is called time-resolved ARPES (TR-ARPES).    In particular, the interaction between electrons and the lattice is responsible for a host of quantum phenomena, including the well-known superconductivity. In this thesis, we study graphite using a new extreme ultraviolet laser. We observe that electrons in graphite preferentially interact with a specific mode of lattice vibration. From the electron dynamics, we quantitatively extract the interaction strength between the electrons and this lattice vibration with a simple, transparent model and find that it agrees well with first-principles calculations. With this demonstration, we show that the maturation of laser technology has significantly advanced the capabilities of TR-ARPES, which readily serves to further our understanding of quantum materials. Event Location: zoom : https://ubc.zoom.us/j/63707269353?pwd=YnZKMzd4K0NKWGtESUJSS2JXNGU5Zz09 Passcode: 486279
Event Time: Wednesday, April 13, 2022 | 12:00 pm - 1:00 pm
Event Location:
Room 318 - Hennings Building
Add to Calendar 2022-04-13T12:00:00 2022-04-13T13:00:00 “Causality constraints on corrections to Einstein gravity" Event Information: In this talk I will describe constraints from causality and unitarity on 2→2 graviton scattering in four-dimensional weakly-coupled effective field theories. Together, causality and unitarity imply dispersion relations that connect low-energy observables to high-energy data. Using such dispersion relations, I will explain how to derive two-sided bounds on gravitational Wilson coefficients in terms of the mass M of new higher-spin states. Such bounds have many implications. For instance, they show that gravitational interactions must shut off uniformly in the limit G→0, prove the scaling with M expected from dimensional analysis, and impose a species bound on theories with a large number of matter fields. In addition they demonstrate the gravity must be weakly coupled at all scales below Planck. Time permitting, I will also comment on the experimental implications of the bounds.   Event Location: Room 318 - Hennings Building
Event Time: Tuesday, April 12, 2022 | 11:00 am - 1:00 pm
Event Location:
Hennings 318 or https://ubc.zoom.us/j/64946668591?pwd=a2xCZEI5Uk5vTVQzR2g0cHlZMlU2QT09
Add to Calendar 2022-04-12T11:00:00 2022-04-12T13:00:00 Searches for Higgs pair production in the 4 b-jet final state with the ATLAS Detector at the LHC Event Information: The Standard Model of Particle Physics is the prevailing theory for describing the interactions of all observed fundamental particles and three of the four known fundamental interactions. However, despite its profound success, the Standard Model fails to explain some observations, such as dark matter and matter-antimatter asymmetry. Additionally, incorporating Einstein’s theory of general relativity has proven difficult. Many proposed extensions to the Standard Model resolve these and other open questions through modifications of the Higgs potential or through new particles which interact with the Higgs boson. This dissertation presents a search for Higgs boson pair production in the signal rich 4 b-jet final state using 136 fb−1 of data collected by the ATLAS detector at the Large Hadron Collider. This search consists of two separate analysis strategies targeting resonant and non-resonant Higgs boson pair production. The resonant search provides sensitivity to the resonant decay of new massive scalar and spin-2 particles predicted by many extensions to the Standard Model. The non-resonant search is directly sensitive to the Higgs potential via the Higgs boson self-coupling and the four-point Higgs to vector boson couplings.  No significant excesses are observed in the resonant search. World-leading upper limits are placed on cross-sections for new massive scalar and spin-2 resonances. These limits exclude a wide range of Kaluza-Klein graviton models and provide leading sensitivity amongst the ATLAS Higgs pair searches for masses above 600 GeV. In the non-resonant search, no evidence for Standard Model Higgs production is found in the non-resonant search. An observed (expected) upper limit of 5.49 (6.73) times the Standard Model cross-section is set. Limits are placed on the Higgs self-coupling and the four-point Higgs to vector boson couplings, with observed (expected) constraints of κλ ∈[-4.7, 12.2] ([-4.1, 10.4]) and κ2V ∈ [0.02, 2.05] ([0.01, 2.06]), respectively. These results are then reinterpreted in the more general Higgs Effective Field Theory and Standard Model Effective Field Theory frameworks. The resulting limits are found to provide leading sensitivity within the HH channel for several parameters and benchmark signals. Event Location: Hennings 318 or https://ubc.zoom.us/j/64946668591?pwd=a2xCZEI5Uk5vTVQzR2g0cHlZMlU2QT09
Event Time: Tuesday, April 12, 2022 | 10:00 am - 1:00 pm
Event Location:
https://ubc.zoom.us/j/68698080843?pwd=cEJ3S283RENpSWROR0I3a0lzbkY2dz09
Add to Calendar 2022-04-12T10:00:00 2022-04-12T13:00:00 PhD defense Xunyu Liang - "Dark Matter in Form of Axion Quark Nuggets: Formation, Detections, and Evidence" Event Information: Over two decades of development since its establishment, the axion quark nugget (AQN) is one of the best-studied macroscopic dark matter candidate with characteristic mass and size of order grams and 0.1 μm respectively. It naturally explains the observed similarity between the dark and visible density in the Universe, i.e. ΩDM ∼ Ωvis, with no fitting parameters, while many conventional dark matter candidates such as the weakly interacting massive particles (WIMPs) and axion do not. This dissertation presents numerous latest key progress of the AQN model, including its formation mechanism in early Universe, and new search strategies such as axion detection and global network. Lastly, we discuss potential evidence of AQNs from the anomalous events recently observed by the Telescope Array(TA) and ANtarctic Impulse Transient Antenna (ANITA) experiments. Event Location: https://ubc.zoom.us/j/68698080843?pwd=cEJ3S283RENpSWROR0I3a0lzbkY2dz09
Event Time: Thursday, April 7, 2022 | 4:00 pm - 5:00 pm
Event Location:
Connect via zoom
Add to Calendar 2022-04-07T16:00:00 2022-04-07T17:00:00 Verification of Quantum Computation Event Information: Abstract: Quantum computers promise to efficiently solve not only problems believed to be intractable for classical computers, but also problems for which verifying the solution is also considered intractable. This raises the question of how one can check whether quantum computers are indeed producing correct results. This task, known as quantum verification, has been highlighted as a significant challenge on the road to scalable quantum computing technology. We review the existing approaches and compare them in terms of structure, complexity and required resources. We also comment on the use of cryptographic techniques which, for many of the presented protocols, has proven extremely useful in performing verification. Finally, we discuss issues related to fault tolerance, experimental implementations and the outlook for this field of research. Bio: Elham Kashefi is Professor of Quantum Computing at the School of Informatics, University of Edinburgh, and Directeur de recherche au CNRS at LIP6 Sorbonne Universite. She co-founded the fields of quantum cloud computing and quantum computing verification, and has pioneered a trans-disciplinary interaction of hybrid quantum-classical solutions from theoretical investigation all the way to actual experimental and industrial commercialisation (Co-Founder of VeriQloud Ltd). She has been awarded several UK, EU and US grants and fellowships for her works in developing applications for quantum computing and communication and was awarded the French 2021 les Margaret Intrapreneur award. She is the senior science team leader of the quantum computing and simulation hub in the UK and member of the executive team of the EU quantum internet alliance. She has been recently elected as the executive director of the Quantum Algorithm Institute in Canada. Event Location: Connect via zoom
Event Time: Thursday, April 7, 2022 | 10:00 am - 11:00 am
Event Location:
Zoom link in description
Add to Calendar 2022-04-07T10:00:00 2022-04-07T11:00:00 Dr. Valentino R. Cooper: Exploring the Chemical Landscape of High Entropy Oxides Event Information: https://ubc.zoom.us/j/68470173961?pwd=RTZEak9Pd01WajVOZHN5SW5YZHcyQT09 Meeting ID: 684 7017 3961 Passcode: 113399 Speaker: Dr. Valentino R. Cooper Title: Exploring the Chemical Landscape of High Entropy Oxides Abstract: High entropy, multi-component metal alloys (HEA), have superior mechanical properties and high radiation tolerances; which are, in part, driven by configurational entropy. Recently, an oxide analogue comprised of MgO, CoO, NiO, CuO and ZnO was synthesized; exhibiting a truly entropy-stabilized, reversible phase transition from a multiphase material to a single rock salt-ordered phase above 850-900°C. This entropy-driven stabilization may engender many unique properties, such as high melting temperatures, radiation resistance and other anomalous responses. Here, we discuss a design strategy for the prediction of synthesizable disordered oxides. Our effort employs first principles studies of 2-component oxides to develop design rules based on the relationship between pairwise enthalpies of formation, DH, and configurational entropy of the disordered material. A similar chemical identity-to-DH map was previously explored using the class of high entropy alloys, where the stability of multicomponent metal alloys was correlated to the enthalpy of mixing of binary and ternary compounds. In this presentation, I will focus on our recent efforts to employ this local enthalpy map as an effective strategy for the discovery of new classes of entropy stabilized oxides. In particular, we are able to use our first principles calculations with Monte Carlo simulations in order to build chemical bonding maps to study the local environment preferences that determine whether a material will phase segregate, to form a single phase with clustered regions, or form a disordered solid solution. This enables us to identify compounds that may be synthesizable or could be stabilized by entropy – thus allowing for more reliable materials discovery and design. This work was supported by the U.S. D.O.E., Office of Science, BES, MSED (first principles calculations) and the LDRD Program of ORNL (simulations), managed by UT-Battelle, LLC, for the U. S. DOE using resources at NERSC and OLCF. Bio: Dr. Valentino R. Cooper is the Section Head for the Materials Theory Modeling and Simulations section in the Materials Sciences and Technology Division at Oak Ridge National Laboratory. He received his Ph. D from the Chemistry Department at the University of Pennsylvania in 2005. Prior to joining ORNL in 2008, he was a post-doctoral associate in the Physics Department of Rutgers University. His research focuses on electronic structure methods for understanding dispersion interactions and in the prediction of functional materials including piezoelectrics and ferroelectrics. Dr. Cooper is a 2013 recipient of the Department of Energy Early Career award. Event Location: Zoom link in description
Event Time: Thursday, April 7, 2022 | 9:00 am - 12:00 pm
Event Location:
https://ubc.zoom.us/j/67782233773?pwd=aU5JNkV0K2g3Y3EvcTV1c09JcmQvUT
Add to Calendar 2022-04-07T09:00:00 2022-04-07T12:00:00 PhD defense Daniel Bruns Event Information: Atomistic modeling of phonon-mediated heat transport in single-walled carbon nanotubes (CNTs) dates to the year 2000, when Berber, Kwon and Tománek, by means of molecular dynamics (MD) simulations, predicted a thermal conductivity of up to 6600 W/mK, suggesting extremely efficient heat transfer in these one-dimensional carbon materials. Since then, many modeling efforts have been undertaken, but some aspects of CNT phonon transport, in particular its domain-size dependence, remain controversial.   In this thesis, we first revisit the two main-stream approaches of modeling phonon-mediated heat transport in CNTs: quantum mechanical calculations in the framework of the Peierls-Boltzmann transport theory (PBTT) and classical MD simulations. Looking at domain size and temperature dependencies of CNT heat transport, we evaluate the strength and limitations of both modeling approaches. In regard to domain size effects, our numerical results offer new insights into the problem of weakly damped acoustic phonons with ever-increasing mean free path.   In the framework of the PBTT, we then focus specifically on the spectrum of three-phonon scattering channels in CNTs. From lowest-order anharmonic perturbation theory, we derive exact asymptotic scaling relations of phonon-phonon scattering rates in the limit of low phonon energies. By adopting a relaxation time approximation of phonon transport, we are then able to unambiguously clarify tube-length effects of CNT heat transport, which we further demonstrate to depend very sensitively on tensile lattice strain. With respect to earlier numerical PBTT calculations on CNTs, we show that a clear line can be drawn between physical and unphysical results. Event Location: https://ubc.zoom.us/j/67782233773?pwd=aU5JNkV0K2g3Y3EvcTV1c09JcmQvUT
Event Time: Monday, April 4, 2022 | 3:00 pm - 4:00 pm
Event Location:
Connect via zoom
Add to Calendar 2022-04-04T15:00:00 2022-04-04T16:00:00 Resonant Chains versus More "Typical" Exoplanetary Systems Event Information: In the field of exoplanets, the most extreme systems often capture our attention, and they teach us interesting lessons. However, statistical modeling of survey data is important too, as it identifies what are the more common processes involved in planet formation. For some systems, three or more planets are linked by mean-motion resonances, forming a "resonant chain." The observable transit timing variations allow masses and orbital parameters to be measured to excellent precision. Their current orbits, including orbital phase information, teaches us about the interactions of planets with disks. The spreading of resonant chains from exact resonance implicates tidal dissipation in the planets. Resonant configurations are rare in the transit survey data though, and we report methods for characterizing the more "typical" close-in exoplanetary systems. After we had gotten used to extreme orbits among exoplanetary gas giants, we found surprisingly small mutual inclinations and eccentricities of the very common close-in systems of super-earths and sub-neptunes. Despite being on sub-AU scales, these architectural properties are very similar to the Solar System. Confronting planet formation theories with all this fossil evidence is an ongoing project.   Event Location: Connect via zoom
Event Time: Thursday, March 31, 2022 | 4:00 pm - 5:00 pm
Event Location:
Hennings 201 (or via zoom)
Add to Calendar 2022-03-31T16:00:00 2022-03-31T17:00:00 Heavy Water: a Canadian (and BC) story Event Information: In the mid-90s I found myself, as a member of the Sudbury Neutrino Observatory (SNO) collaboration, a recipient and custodian of 1000 tonnes of “spare” heavy water, book value $300M. How such a rare asset came to exist in Canada is a complex story of nuclear physics, geopolitics, world war, flight and exile. For a while the tale runs along the fringe of the Manhattan Project saga, but it largely concerns reactors rather than bombs. The story crosses continents (Norway-France-Canada) in circumstances anyone familiar with the news at this moment can readily imagine. Part of it is however set far away from conflict and from well-known centres of nuclear research, in the south-eastern corner of British Columbia.   Event Location: Hennings 201 (or via zoom)
Event Time: Thursday, March 31, 2022 | 10:00 am - 11:00 am
Event Location:
Zoom link in description
Add to Calendar 2022-03-31T10:00:00 2022-03-31T11:00:00 Kwabena Bediako: New Twists on Chemistry and Physics in Moiré Superlattices Event Information: https://ubc.zoom.us/j/68470173961?pwd=RTZEak9Pd01WajVOZHN5SW5YZHcyQT09 Meeting ID: 684 7017 3961 Passcode: 113399 Speaker: Kwabena Bediako, Assistant Professor at UC Berkeley, Dept. of Chemistry Title: New twists on chemistry and physics in moiré superlattices     Abstract: Atomically thin or two-dimensional (2D) materials can be assembled into bespoke heterostructures to produce some extraordinary physical phenomena. Likewise, these highly tunable materials are useful platforms for exploring fundamental questions of interfacial chemical/electrochemical reactivity. One exciting and relatively recent example is the formation of moiré superlattices from azimuthally misoriented (twisted) layers. These moiré superlattices result in flat bands that lead to an array of correlated electronic phases. However, in these systems, complex strain relaxation can also strongly influence the fragile electronic states of the material. Precise characterization of these materials and their properties is therefore critical to the understanding of the behavior of these novel moiré materials (and 2D heterostructures in general). In this talk, I will discuss how spontaneous mechanical deformations (atomic reconstruction) and resultant intralayer strain fields at moiré superlattices of twisted bilayer graphene have been quantitatively imaged using 4D-STEM Bragg interferometry. I will also discuss the impact of these mechanical deformations to the electronic band structure of these moiré superlattices and the correlated electronic phases they host. The talk will then explore how various degrees of freedom that are unique to 2D materials may be used to tailor interfacial chemistry at well-defined mesoscopic electrodes and the outlook for new paradigms of functional materials for energy conversion and low-power electronic devices. Bio: Kwabena was born in Ghana, West Africa. He moved to the US in 2004 for his undergraduate studies in Chemistry at Calvin College, MI, graduating with honors in 2008. After a year working at UOP Honeywell in IL where he researched new catalysts for the petrochemical and gas processing industries, he traveled from the Midwest to the East Coast to begin his graduate studies in Inorganic Chemistry with Prof. Daniel Nocera at MIT (and later Harvard University). His graduate research focused on structural and mechanistic studies of water splitting electrocatalysis at cobalt and nickel compounds. After receiving his Ph.D. in 2015 from Harvard University, Kwabena began postdoctoral work in Prof. Philip Kim's group in the Department of Physics at Harvard, where he studied ion intercalation and quantum transport in 2D van der Waals heterostructures. In July 2018, Kwabena joined the faculty of the UC Berkeley Department of Chemistry. Awards received include: AFOSR Young Investigator award, ONR Young investigator award, DOE Early Career Award, Gordon and Betty Moore Materials Synthesis Fellow, and CIFAR–Azrieli Global Scholar. Event Location: Zoom link in description
Event Time: Monday, March 28, 2022 | 3:00 pm - 4:00 pm
Event Location:
Connect via zoom
Add to Calendar 2022-03-28T15:00:00 2022-03-28T16:00:00 Localizations and Lenses: Looking towards Cosmology with CHIME/FRB Event Information: The Canadian Hydrogen Intensity Mapping Experiment (CHIME) has discovered thousands of fast radio bursts (FRBs). The extremely high all-sky rate of FRBs implies that they have the potential to become powerful cosmological probes. Unlocking this potential requires localizing a large sample of FRBs to their host galaxies. Until now, precise localization within the host galaxy has only been accomplished in follow-up observations of repeating sources. Here, we demonstrate the localization of FRB 20210603A using very long baseline interferometry (VLBI) at its time of first detection. This is an important milestone towards realizing CHIME/FRB Outriggers: a widefield, blind VLBI survey dedicated to localizing a large sample of FRBs. Finally, I will discuss a novel time-domain search for gravitationally-lensed FRBs, as a first application of FRBs to cosmological measurements. Our results imply that the cosmological dark matter at redshift z~0.1 cannot be composed exclusively of ~10^-3 solar mass compact objects. Event Location: Connect via zoom
Event Time: Thursday, March 24, 2022 | 4:00 pm - 5:00 pm
Event Location:
Connect via zoom
Add to Calendar 2022-03-24T16:00:00 2022-03-24T17:00:00 More Than Pretty Pictures Event Information: Abstract Images and figures — visual representations of scientific data and concepts — are critical components of science and engineering research. They communicate in ways that words cannot. They can clarify or strengthen an argument and spur interest into the research process. But it is important to remember that a visual representation of a scientific concept or data is a re-presentation and not the thing itself –– some interpretation or translation is always involved. Just as writing a journal article, one must carefully plan what to "say," and in what order to "say it."  The process of making a visual representation requires you to clarify your thinking and improve your ability to communicate with others. In this talk, I will show my own approach to creating depictions in science and engineering—the successes and failures. Included will be a discussion about how far can we go when "enhancing" science images. Bio Science photographer Felice Frankel is a research scientist at the Massachusetts Institute of Technology in the department of Chemical Engineering with additional support from Mechanical Engineering. She joined MIT in 1994. Frankel is a Fellow of the American Association for the Advancement of Science, and was awarded a Guggenheim Fellowship among others. Working in collaboration with scientists and engineers, Felice Frankel's images have appeared in outlets such as National Geographic, Nature, Science, Angewandte Chemie, Advanced Materials, Materials Today, PNAS, Newsweek, Scientific American, Discover, Popular Science and New Scientist, among others. She is working on her 8th book, a series of handbooks: "THE VISUAL ELEMENTS, communicating science and engineering." Website: www.felicefrankel.com Event Location: Connect via zoom
Event Time: Thursday, March 24, 2022 | 10:00 am - 11:00 am
Event Location:
Zoom link in description
Add to Calendar 2022-03-24T10:00:00 2022-03-24T11:00:00 Marlou Slot: Atom by atom and layer by layer: Designing and realizing electronic quantum matter Event Information: https://ubc.zoom.us/j/68470173961?pwd=RTZEak9Pd01WajVOZHN5SW5YZHcyQT09 Meeting ID: 684 7017 3961 Passcode: 113399 Speaker: Marlou Slot; National Institute of Standards and Technology (NIST) - Gaithersburg, Maryland, United States Title: Atom by Atom and Layer by Layer: Designing and Realizing Electronic Quantum Matter Abstract: Quantum simulators are a versatile tool to study the behavior of quantum matter in a controlled way. Elusive or complex quantum systems are simulated using accessible quantum systems that can be manipulated at will. While platforms based on, among others, ultracold atoms and photons are well-established, electronic platforms are currently being developed. The scanning tunneling microscope (STM) is uniquely suited to create and manipulate electronic 2D potential landscapes at will in-situ. By atomic-scale patterning of the 2D electron gas at specific metal surfaces, the electrons can be molded into electronic lattices with nearly any geometry. In this talk, I will present CO molecules adsorbed on a Cu(111) surface as a highly-tunable electronic quantum simulator, in which the lattice geometry, the orbital degree of freedom, the dimension and the topology can be tailored [1-4]. Moving beyond the in-situ approach, ex-situ nanofabricated twisted van der Waals devices pave the way to study electron-electron interactions in tailor-made 2D potential landscapes [5]. I will demonstrate high-resolution gate-tunable Landau level spectroscopy and signatures of correlated states in twisted double bilayer graphene, expanding the quantum simulation toolkit from atom by atom to layer by layer. [1] M. R. Slot et al., Nat. Phys. 13, 672 (2017) [2] S. N. Kempkes and M. R. Slot et al., Design and characterization of electrons in a fractal geometry, Nat. Phys. 15, 127 (2019) [3] M. R. Slot and S. N. Kempkes et al., p-Band Engineering in Artificial Electronic Lattices, PRX 9, 011009 (2019) [4] S. N. Kempkes and M. R. Slot et al., Robust zero-energy modes in an electronic higher-order topological insulator, Nat. Mater. 18, 1292 (2019) [5] D.M. Kennes et al., Moiré heterostructures as a condensed-matter quantum simulator, Nat. Phys. 17, 155 (2021) Bio: Marlou Slot is a Rubicon Postdoctoral Fellow and NIST-Georgetown PREP Fellow working with Dr. Joseph Stroscio at the National Institute of Standards and Technology. She obtained her PhD from Utrecht University working with Prof. Daniel Vanmaekelbergh and Prof. Ingmar Swart. Prior to that, she obtained her undergraduate degree from RWTH Aachen University and EPFL Lausanne and she was a research assistant at Forschungszentrum Jülich. Her research interests focus on designer quantum matter realized and/or measured using scanning probe microscopy, including van der Waals heterostructures and in-situ patterned surfaces. Event Location: Zoom link in description
Event Time: Monday, March 21, 2022 | 3:00 pm - 4:00 pm
Event Location:
Connect via zoom
Add to Calendar 2022-03-21T15:00:00 2022-03-21T16:00:00 White dwarf crystallization as revealed by Gaia Event Information: White dwarfs are stellar embers that simply cool down for the rest of time, eventually freezing into a solid state. This predictable evolution makes them precise cosmic clocks; they have been used for decades to measure the ages of stellar populations. But data from the Gaia space observatory is now challenging our understanding of white dwarf evolution and calling into question the accuracy of this age dating technique. The cooling process appears to be much more delayed by the onset of crystallization than predicted by current models. In this talk, I will present my recent theoretical work aimed at improving the constitutive physics of white dwarf cooling models (in particular the physics of core crystallization) and discuss outstanding uncertainties that should be addressed before white dwarf cosmochronology can reach its full potential. Event Location: Connect via zoom
Event Time: Thursday, March 17, 2022 | 4:00 pm - 5:00 pm
Event Location:
Connect via zoom
Add to Calendar 2022-03-17T16:00:00 2022-03-17T17:00:00 Why I Count Calories for a Living Event Information: Calorimetry measures heat effects, so why should one care?  Enthalpies of formation and phase transformation sing about making and breaking chemical bonds. Heat capacities and entropies dance about how atoms and electrons jostle each other, move, and disorder.  Combining thermodynamic and structural studies provides illuminates what materials form in nature, in the lab, and in technology. I illustrate the insights gained from calorimetry by three examples from our work. (1) Zinc sulfide (ZnS) is important as a semiconductor and an ore mineral. It occurs in two polymorphs, sphalerite and wurtzite. Our recent calorimetric studies have highlighted the importance of surface energy in changing the thermodynamic stability of these polymorphs, especially at the nanoscale, explaining their otherwise puzzling occurrences. (2) Pyrochlore is an ordered derivative of the simple fluorite structure and it has been proposed as a nuclear waste form. However, it is subject to radiation damage, leading to disorder and loss of crystallinity.  A combination of neutron diffraction and calorimetry has shown that the nominally disordered or amorphized products of heavy ion irradiation contain persistent nanodomains of ordered weberite structure which strongly affect stability and physical properties, complicating simple pictures of radiation tolerance. (3) Zeolites and metal organic frameworks contain immense structural porosity, increasing their volume many times over that of a dense phase. Calorimetry has shown that the energetic penalty of porosity is amazingly small, enabling the synthesis, stability, and persistence of many new and useful materials. In all these cases, the microscopic structural and macroscopic thermochemical insights work together to understand and predict the  existence and behavior of materials. Event Location: Connect via zoom
Event Time: Thursday, March 17, 2022 | 10:00 am - 11:00 am
Event Location:
Zoom link in description
Add to Calendar 2022-03-17T10:00:00 2022-03-17T11:00:00 Alexandra Navrotsky: Recent Developments in High Temperature Calorimetry Event Information: https://ubc.zoom.us/j/68470173961?pwd=RTZEak9Pd01WajVOZHN5SW5YZHcyQT09 Meeting ID: 684 7017 3961 Passcode: 113399 Speaker: Alexandra Navrotsky - Center for Materials of the Universe (MotU) , Arizona State University Title: Recent developments in high temperature calorimetry Abstract: A variety of high temperature calorimetric techniques have recently advanced for application to refractory oxides and related materials. These include improvements in oxide melt solution calorimetry at temperatures up to 1500 ⁰C, differential thermal analysis to 2500 ⁰C, and “drop-n-catch” calorimetry to 3000 ⁰C. Used together, these methods enable one to draw a more complete picture of phase stability, order-disorder, melting and crystallization, and dissolution of solids in silicate melts. These methods will be illustrated using examples from rare earth materials chemistry. New developments in the calorimetry of chalcogenides and mixed anion materials will also be presented. The synergy among calorimetry, first principles calculations and computations of phase diagrams will be emphasized. Bio: Alexandra Navrotsky - Professor, School of Molecular Sciences and School for Engineering of Matter, Transport and Energy Affiliated Faculty Member, School of Earth and Space Exploration Director, Center for Materials of the Universe Event Location: Zoom link in description