Events List for the Academic Year
Event Time:
Thursday, July 17, 2025 | 10:00 am - 11:00 am
Event Location:
BRIM 311
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2025-07-17T10:00:00
2025-07-17T11:00:00
The Strange Universe of Quantum Phases Driven by Interplay between Multipoles and Conduction Electrons
Event Information:
Multipolar moments embedded in a metallic setting paves a new route to extend the landscape of novel quantum phenomena beyond the spin-only paradigm [1]. A model material platform for exploring multipolar physics is the cubic heavy-fermion system PrTr_2Al_20 (Tr = Ti, V). This system features a nonmagnetic ground state in which the magnetic dipolar moment (spin) is absent, but higher-rank multipolar moments (quadrupoles and octupoles) are active [2]. The Kondo entanglement of these local multipolar moments with conduction electrons results in a rich phase diagram comprising multipolar orders, non-Fermi liquid (NFL) phase, and exotic superconductivity [2-5]. In this talk, I will present our experimental investigation into the multipolar ordered phases multipolar quantum criticality and novel superconductivity in PrTr_2Al_20, which contrast sharply from those in the familiar magnetic settings. References [1] S. Paschen and Q. Si, Nat. Rev. Phys. 3, 9-26 (2021) [2] A. Sakai and S. Nakatsuji, J. Phys. Soc. Jpn. 80, 063701 (2011) [3] K. Matsubayashi, T. Tanaka, A. Sakai et al., Phys. Rev. Letts. 109, 187004 (2012) [4] M. Fu, A. Sakai, N, Sogabe et al., J. Phys. Soc. Jpn. 89, 013704 (2020) [5] A. Sakai, Y. Matsumoto, M. Fu et al., Nat. Commun 16, 2114 (2025)
Speaker Bio: Dr. Mingxuan Fu received her undergraduate degree in Physics from the University of Toronto in 2010 and earned her PhD in Experimental Condensed Matter Physics from McMaster University in 2015. She subsequently held a joint postdoctoral position with Professor Collin Broholm at Johns Hopkins University and the NIST Center for Neutron Research, followed by a NSERC postdoctoral fellowship under Professor Stephen Julian at the University of Toronto (2015–2019). In 2019, Dr. Fu joined the University of Tokyo as a JSPS Fellow and is currently a Project Assistant Professor in the Department of Physics. She is a member of Professor Satoru Nakatsuji’s research group. Her research experiences encompass several central themes in quantum materials, including quantum critical phenomena and exotic superconductivity in strongly correlated electron systems, frustrated quantum magnetism, and topological materials, and her current focus is on multipolar-driven quantum phenomena and functional topological antiferromagnets.
Event Location:
BRIM 311
Event Time:
Tuesday, June 24, 2025 | 11:00 am - 12:00 pm
Event Location:
In the atrium outside of HENN 200
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2025-06-24T11:00:00
2025-06-24T12:00:00
PHAS TUESDAY Tea!
Event Information:
We welcome you to our new Spring Weekly PHAS TUESDAY TEA!
This is the best physics community tea event in town!
Join us Tuesdays from 11am-noon in the atrium outside of HENN 200 for some social chit-chat and tasty treats!
We welcome all new summer students, new grad students, staff and faculty to meet new-to-you colleagues, catch up with your physics community and to learn about current happenings in the PHAS Department.
Your hosts from the EDI Community Building Working Group are:
Jess McIver
Adele Ruosi
Evan Goetz
Mona Berciu
Howard Li
Mandana Amiri
We look forward to meeting you!
Event Location:
In the atrium outside of HENN 200
Event Time:
Tuesday, June 24, 2025 | 11:00 am - 12:00 pm
Event Location:
In the atrium outside of HENN 200
Add to Calendar
2025-06-24T11:00:00
2025-06-24T12:00:00
PHAS TUESDAY Tea!
Event Information:
We welcome you to our new Spring Weekly PHAS TUESDAY TEA!
This is the best physics community tea event in town!
Join us Tuesdays from 11am-noon in the atrium outside of HENN 200 for some social chit-chat and tasty treats!
We welcome all new summer students, new grad students, staff and faculty to meet new-to-you colleagues, catch up with your physics community and to learn about current happenings in the PHAS Department.
Your hosts from the EDI Community Building Working Group are:
Jess McIver
Adele Ruosi
Evan Goetz
Mona Berciu
Howard Li
Mandana Amiri
We look forward to meeting you!
Event Location:
In the atrium outside of HENN 200
Event Time:
Thursday, June 19, 2025 | 7:30 pm - 10:00 pm
Event Location:
Fox Cabaret (2321 Main St, Vancouver, BC V5T 3C9)
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2025-06-19T19:30:00
2025-06-19T22:00:00
Science, Stand-up, & Song
Event Information:
Science, Stand-Up, & Song is a science education initiative, which aims to bridge the gap between scientists and the public: connecting scientists with the community to laugh and learn together!
The show is hosted by Dr. Marissa Lithopoulos and will include 4 hilarious comedians, as well as a panel of 3 brilliant scientists. Marissa will also provide live music along the way!
The upcoming event is at 7:30 PM on June 19th at the Fox Cabaret!
Comedians:
Yumi Nagashima
Alannah Brittany
Bradley Fun
special guest
Scientists:
Dr. Chana Davis
Dr. David Ng
Dr. Adriana Suarez-Gonzalez
Event Location:
Fox Cabaret (2321 Main St, Vancouver, BC V5T 3C9)
Event Time:
Thursday, June 19, 2025 | 6:00 pm - 7:30 pm
Event Location:
Vancouver Public Library - Central Branch (Alice MacKay Room, Lower Level)
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2025-06-19T18:00:00
2025-06-19T19:30:00
How the Universe Works: An Introduction to Galactic Radio Astronomy
Event Information:
Curious about how the universe actually works? Join the experts from UBC’s Department of Physics and Astronomy to find out fun facts about everything from the Milky Way to radio waves in this new, accessible science series: How the Universe Works! All are welcome!
Abstract:
Imagine that you look up on a dark clear night, seeing countless stars scattered across the sky, divided by the hazy band of the Milky Way—our Galaxy. The haziness of the Galactic Plane is caused by vast clouds of dust lining the Galactic disk, which obscure much of the Galaxy from our sight. But what if we could see beyond the dust, revealing the hidden structures and objects that share our cosmic home? This is where Galactic radio astronomy truly shines, allowing us to peer through the darkness and uncover the Milky Way’s secrets.
In this talk, we’ll step beyond the limits of optical astronomy and into the invisible world of radio waves, mapping our Galaxy in a whole new way. From the birth of radio astronomy to the frontiers of modern research, we’ll explore how these maps not only help us understand the Milky Way but also allow us to remove it from our view—clearing the way to see the universe beyond.
Bio:
Dr. Thomas J. Rennie is a postdoctoral researcher at the University of British Columbia, where he specializes in analyzing and interpreting radio maps of the Milky Way. After obtaining his Ph.D., Dr. Rennie joined UBC to work on the Canadian Galactic Emission Mapper (CGEM) project, which focuses on a new telescope being built at the Dominion Radio Astrophysical Observatory (DRAO) in Penticton, BC. CGEM maps will play a key role in a global effort to further our understanding of our Galaxy and to look deeper and reveal the echo of the Big Bang (the Cosmic Microwave Background, or CMB) and probe the very earliest moments in the history of the universe.
Learn More:
About the Canadian Galactic Emission Mapper (CGEM) project: https://cgem.ubc.ca/
About the Dominion Radio Astrophysics Observatory (DRAO): https://nrc.canada.ca/en/research-development/nrc-facilities/dominion-radio-astrophysical-observatory-research-facility
About the "Big Bang": https://science.nasa.gov/universe/the-big-bang/
About the Cosmic Microwave Background: https://lambda.gsfc.nasa.gov/education/graphic_history/microwaves.html
About Thomas Rennie: https://tjrennie.github.io/index.html
Event Location:
Vancouver Public Library - Central Branch (Alice MacKay Room, Lower Level)
Event Time:
Tuesday, June 17, 2025 | 11:00 am - 12:00 pm
Event Location:
In the atrium outside of HENN 200
Add to Calendar
2025-06-17T11:00:00
2025-06-17T12:00:00
PHAS TUESDAY Tea!
Event Information:
We welcome you to our new Spring Weekly PHAS TUESDAY TEA!
This is the best physics community tea event in town!
Join us Tuesdays from 11am-noon in the atrium outside of HENN 200 for some social chit-chat and tasty treats!
We welcome all new summer students, new grad students, staff and faculty to meet new-to-you colleagues, catch up with your physics community and to learn about current happenings in the PHAS Department.
Your hosts from the EDI Community Building Working Group are:
Jess McIver
Adele Ruosi
Evan Goetz
Mona Berciu
Howard Li
Mandana Amiri
We look forward to meeting you!
Event Location:
In the atrium outside of HENN 200
Event Time:
Thursday, June 12, 2025 | 5:00 pm - 6:00 pm
Event Location:
CEME 2202
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2025-06-12T17:00:00
2025-06-12T18:00:00
Modeling Poromechanics in Earthquake and Faulting Phenomena
Event Information:
Abstract:
Understanding strain localization and fault slip in earthquake systems requires insight into the coupled processes of fluid flow and deformation in porous media. This talk explores recent advances in modeling poromechanical mechanisms that govern these phenomena. Using physics-based numerical simulations within a continuum two-phase framework, the study captures the interplay between fluid pressure diffusion, nonlinear rheology, and dynamic weakening in compressible, fluid-saturated fault gouge. Results reveal how different frictional formulations influence shear band thickness, rupture speed, and energy dissipation. The transition between fast and slow slip modes will also be examined, alongside stability analyses that map the conditions for fluid-induced seismicity.
Bio:
Luca Dal Zilio is Assistant Professor at Nanyang Technological University (Singapore), where he leads the Computational Geophysics Lab at the Earth Observatory of Singapore. He was previously a senior researcher at ETH Zurich and postdoctoral researcher at Caltech. His research focuses on earthquake physics, poromechanics, and high-performance simulation of coupled geophysical processes. In 2025, he received a Nanyang Assistant Professorship Award to advance multi-scale modeling of hydromechanical fault systems.
Event Location:
CEME 2202
Event Time:
Wednesday, June 11, 2025 | 2:00 pm - 3:00 pm
Event Location:
CEME 2202
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2025-06-11T14:00:00
2025-06-11T15:00:00
Chemo-mechanics: from delamination of adhesive joints to failure of Li ion batteries
Event Information:
Abstract:
Crack growth in materials often arises from a coupled interplay between mechanical loading and chemical degradation. This talk explores two systems where such interactions govern failure: adhesively bonded ship structures in marine environments, and nickel-rich single-crystal cathode particles in lithium-ion batteries. The first part addresses delamination in maritime structures, where a composite superstructure is bonded to a steel hull using a thick (10mm) MMA adhesive. Drawing on results from the QUALIFY project, we examine saltwater-induced delamination, where competing mechanisms—cathodic delamination, free corrosion, and hydrolysis—can each dominate. Experiments identify hydrolysis as the main driver under oxygen- and ion-limited conditions. A transport-reaction model predicts crack growth based on water diffusion along the interface and accumulation of reaction products, leading to constant crack velocity in diffusion-limited regimes. The second part shifts to energy storage materials. In next-generation batteries, layered nickel-rich cathode particles swell during lithiation. Optical microscopy reveals lithium diffusion patterns within single crystals. Coupled chemo-mechanical simulations show that rapid discharge—on the order of 10 minutes—induces internal stresses sufficient to fracture large particles. These case studies illustrate how stress-assisted chemical processes drive failure across scales, and how combining experiments with transport-reaction-fracture models enables prediction of material reliability in chemically active environments.
Bio:
Norman Fleck’s main interests are in Micromechanics: the development of physically based models of deformation and fracture of engineering materials by experiment, theory and numerical analysis. The research is of broad scope and combines scientific insights with practical applications. A guiding philosophy has been to condense practical engineering design problems into fundamental problems in mechanics, then generate constitutive models and implement them within finite element code. Examples include compressive failure of engineering composites by microbuckling, sintering of thermal barrier coatings and the dependence of their toughness and erosion resistance upon microstructural morphology, coupled electro-mechanical switching of ferroelectric devices, fatigue life prediction, the mechanics of metal rolling of thin foil, size effects in plasticity—from hardness testing to cleavage at crack tips—and, more recently, electro-chemo-mechanical phenomena in solid-state lithium-ion batteries. Norman Fleck is Professor of Mechanics of Materials (since 1997) and Director of the Cambridge Centre for Micromechanics (since 1990) at the University of Cambridge. He was Head of the Mechanics, Materials and Design Division from 1996 to 2008. He is a member of several learned societies (FRS, FREng, NAE, Fellow of the European Mechanics Society), serves on advisory committees (Board of IUTAM), editorial boards of leading mechanics journals, and holds an honorary doctorate from Eindhoven University of Technology.
Event Location:
CEME 2202
Event Time:
Tuesday, June 10, 2025 | 11:00 am - 12:00 pm
Event Location:
In the atrium outside of HENN 200
Add to Calendar
2025-06-10T11:00:00
2025-06-10T12:00:00
PHAS TUESDAY Tea!
Event Information:
We welcome you to our new Spring Weekly PHAS TUESDAY TEA!
This is the best physics community tea event in town!
Join us Tuesdays from 11am-noon in the atrium outside of HENN 200 for some social time with your physics peeps!
We welcome all new summer students, new grad students, staff and faculty to meet new-to-you colleagues, catch up with your physics community and to learn about current happenings in the PHAS Department.
Your hosts from the EDI Community Building Working Group are:
Jess McIver
Adele Ruosi
Evan Goetz
Mona Berciu
Howard Li
Mandana Amiri
We look forward to meeting you!
Event Location:
In the atrium outside of HENN 200
Event Time:
Thursday, June 5, 2025 | 11:00 am - 12:00 pm
Event Location:
HENN 318
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2025-06-05T11:00:00
2025-06-05T12:00:00
Quantum chaotic systems and black holes: puzzles and lessons from an information-theoretic perspective
Event Information:
Abstract:
Most systems in nature are chaotic many-body systems, and show the universal phenomenon of thermalization. While some "coarse-grained" aspects of thermalization are familiar from our everyday lives, quantum information theory provides a window into more fine-grained universal properties of thermalizing systems. I will discuss examples from my work of insights and surprises that come from asking operationally motivated questions about quantum chaotic systems. I will also introduce approaches for addressing the elusive question of how and why universality emerges across systems with widely differing microscopic dynamics. Remarkably, there is a lot of evidence that black holes in their fundamental description can be seen as examples of highly chaotic quantum many-body systems. While this principle allows us to make predictions for black holes based on properties of quantum chaotic systems, such predictions are often in conflict with the semiclassical description of gravity in a regime where it should naively be valid. I will discuss a proposal for using computational complexity to understand the subtle relation between the semiclassical and fundamental descriptions of the black hole interior.
Bio:
Shreya Vardhan is a postdoctoral fellow at the Institute for Quantum Information and Matter at Caltech. She received her Ph.D. at MIT in 2022, and was a postdoc at the Stanford Institute for Theoretical Physics from 2022 to April 2025. Shreya's research interests lie at the intersection of quantum information theory, quantum many-body physics, and quantum gravity. Her work has included topics in entanglement dynamics, the black hole information loss paradox, hydrodynamics, and information-theoretic properties of states in conformal field theories. One of her key goals in the next few years will be to better understand the interplay between the dynamics of information and the flow of energy and other conserved quantities in many-body systems. Another important goal will be to test and develop recent ideas about the role of complexity in black hole physics in the context of more realistic gravity models.
Learn More:
Watch her videos (there are more on Youtube):
BHI Colloquium Talks | 11.18.2024 | Shreya Vardhan (Stanford University): https://www.youtube.com/watch?v=uo8OmGoz8VY
Shreya Vardhan (Stanford University): Entanglement dynamics from universal low-lying modes: https://www.youtube.com/watch?v=kYHd7MWatiY
Mixed-state entanglement and information recovery in evaporating black holes: https://www.youtube.com/watch?v=ItevkmLw7rE
Read her thesis: Chaos and Thermalization in Quantum Many-Body Systems and Gravity: https://dspace.mit.edu/bitstream/handle/1721.1/150679/vardhan-vardhan-phd-physics-2022-thesis.pdf?sequence=1&isAllowed=y
Event Location:
HENN 318
Event Time:
Tuesday, June 3, 2025 | 11:00 am - 12:00 pm
Event Location:
In the atrium outside of HENN 200
Add to Calendar
2025-06-03T11:00:00
2025-06-03T12:00:00
PHAS TUESDAY Tea!
Event Information:
We welcome you to our new Spring Weekly PHAS TUESDAY TEA!
This is the best physics community tea event in town!
Join us Tuesdays from 11am-noon in the atrium outside of HENN 200 for some social chit-chat and tasty treats!
We welcome all new summer students, new grad students, staff and faculty to meet new-to-you colleagues, catch up with your physics community and to learn about current happenings in the PHAS Department.
Your hosts from the EDI Community Building Working Group are:
Jess McIver
Adele Ruosi
Evan Goetz
Mona Berciu
Howard Li
Mandana Amiri
We look forward to meeting you!
Event Location:
In the atrium outside of HENN 200
Event Time:
Monday, June 2, 2025 | 11:00 am - 12:00 pm
Event Location:
HENN 318
Add to Calendar
2025-06-02T11:00:00
2025-06-02T12:00:00
A many-body physics perspective on quantum error correction
Event Information:
Abstract:
Quantum computers hold transformative promise for both scientific and real-world applications, but their practical operation is often hindered by errors and decoherence. In this talk, I will discuss how the co-design of quantum hardware and algorithms creates new opportunities with today’s non-fault-tolerant devices. First, focusing on one such computational platform—neutral atom arrays—I will explore the design of a topological qubit and demonstrate how it enables robust quantum information processing. Then, inspired by recent advances in many-body quantum dynamics, I will examine certain fundamentally out-of-equilibrium dynamical critical phenomena in quantum and classical systems. I will show how these phenomena can be harnessed for quantum state preparation in both analog systems and quantum circuits incorporating measurement and feedback, offering a scalable route to passive quantum error correction.Bio:
Rhine Samajdar is a Princeton Quantum Initiative Postdoctoral Fellow in the Department of Physics and PCTS at Princeton University. His research interests lie at the interface of theoretical quantum information science, condensed matter physics, and atomic, molecular, and optical physics. Prior to joining Princeton, he obtained his PhD in Physics from Harvard University in 2022 working with Subir Sachdev. His work has demonstrated how quantum computation can be used to realize, probe, and control novel phases of quantum matter, providing new insights into topological architectures, quantum algorithms, and nonequilibrium dynamics.
Learn More:
About Rhine's research: https://pcts.princeton.edu/people/rhine-samajdar
Event Location:
HENN 318
Event Time:
Friday, May 30, 2025 | 12:00 pm - 2:30 pm
Event Location:
HEBB 116
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2025-05-30T12:00:00
2025-05-30T14:30:00
Searching for Millisecond and Slow Pulsars with CHIME
Event Information:
Abstract:Born in core-collapse supernovae, pulsars are highly-magnetized, spinning neutron stars, which emit highly directional electromagnetic radiation in beams above their magnetic poles. This produces a lighthouse effect: we see a pulse of radiation as the beam crosses our line-of-sight, repeating with each rotation of the neutron star.
These periodic pulses can reveal a wealth of information about the neutron star, its environment, material the signal encounters on its way to Earth, and even the behaviour of spacetime. There are many remaining mysteries about these objects and, thus far, we have only discovered a small fraction of them. New surveys to discover more pulsars, therefore, have great scientific potential.In this thesis I use the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope to perform two distinct pulsar surveys on the same small patch of sky. These serve as pilots for larger-scale surveys over the entire CHIME-visible sky.
The CHIME All-sky Multi-day Pulsar Stack Search (CHAMPSS) survey uses the data stream from the CHIME/FRB instrument, taking data from the whole Northern sky as it passes overhead and combining data from multiple days to detect fainter pulsars. However, it is not sensitive to the fastest pulsars with periods below ∼ 10 ms.
The other survey uses the CHIME/Pulsar system to take multiple observations of the same point on the sky, correcting for different amounts of material between the Earth and potential pulsars. This scheme lets it detect the fastest pulsars further out into the Galaxy. However, the CHIME/Pulsar survey does not combine multiple days’ data and so will not detect the faintest pulsars found by CHAMPSS. The two surveys are thus sensitive to different, but overlapping, sections of the pulsar population, and further demonstrate the collaborative nature of CHIME which allows multiple experiments to run simultaneously.
In this thesis I describe the software pipeline for each survey. The CHIME All-sky Multi-day Pulsar Stack Search (CHAMPSS) pipeline I developed as part of a group; the CHIME/Pulsar pipeline was an individual project. I also present PSR J2108+5001, a newly discovered pulsar in the pilot survey area, and J1629+4636, J2100+4711, J2151+5128, and J2319+4919 which were discovered during a subsequent CHAMPSS commissioning survey.
Event Location:
HEBB 116
Event Time:
Thursday, May 29, 2025 | 11:00 am - 12:00 pm
Event Location:
HENN 318
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2025-05-29T11:00:00
2025-05-29T12:00:00
Condensed matter theory in the quantum information era
Event Information:
Abstract:
The rapid development of new experimental platforms enables the study of quantum many-body systems using both existing materials and synthetic matter. This progress has spurred the search for novel phenomena in regimes beyond traditional near-equilibrium settings, two aspects of which will be explored in this talk. We will first discover that kinetic constraints and symmetries can be utilized to halt quantum thermalization, and to even shield a system from decohering. These striking outcomes emerge via the mechanism of Hilbert space fragmentation--a phenomenon since realized experimentally in various platforms. We will then explore the physics of many-body ground states and show how even “weak” measurements can tame the rigidly universal properties emerging at quantum critical points. Drawing inspiration from quantum information, this discovery informs the design of optimally resilient teleportation protocols that transfer critical wavefunctions between distant labs. Finally, we will discuss open questions and related ideas in the field.
Bio:
I am currently a postdoctoral fellow at the California Institute of Technology (Caltech), where I hold a Burke Institute Prize Fellowship. I completed undergraduate degrees in both Physics and Mathematics in Zaragoza, Spain. After finishing a master's program in Theoretical and Mathematical Physics in Munich---with a thesis on the use of variational methods for lattice gauge theories at the Max Planck Institute for Quantum Optics---I pursued a PhD at the Technical University of Munich (TUM) under the supervision of Prof. Pollmann, supported by a "la Caixa" fellowship. My doctoral research led to the discovery of Hilbert space fragmentation, an ergodicity-breaking mechanism that deepens our understanding of the role of symmetries in the dynamics of many-body systems.
As a postdoctoral fellow at Caltech, I have developed a research program focused on various aspects of quantum many-body physics in the presence of measurements and decoherence---a relevant area to emerging quantum technologies. My recent work includes the demonstration and quantification of entanglement generation in open (mixed-state) systems, the characterization of non-Abelian topological order under decoherence, and the identification of novel phenomena induced by quantum measurements.
Learn More:
About Pablo: https://www.pma.caltech.edu/people/pablo-sala
Event Location:
HENN 318
Event Time:
Wednesday, May 28, 2025 | 2:00 pm - 3:00 pm
Event Location:
Via zoom
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2025-05-28T14:00:00
2025-05-28T15:00:00
Toward the generation of high-energy temporal solitons in a free-space enhancement cavity
Event Information:
Abstract:
A soliton is a wave packet that retains its shape as it propagates due to a balance between the dispersion and non-linear response of a medium. These wave packets have garnered interest in the areas of frequency generation and ultrafast laser mode-locking due to their stability and self-reinforcing properties. Here, we describe the development of a system designed to be capable of generating such a wave packet in a free-space ultrafast enhancement cavity. This consists of three main parts: a homemade ultrafast fibre laser system, the enhancement cavity itself, and a frequency locking system to stabilize the laser output relative to the cavity resonances. The laser is capable of outputting up to 4 W average power and pulse durations on the order of 200 fs, while the overall system has so far demonstrated an average power enhancement factor of 204, corresponding to a potential intracavity average power of more than 800 W. This demonstrates the potential of this platform to support soliton generation, allowing one to study soliton dynamics or improve upon current intracavity non-linear frequency conversion processes.
Event Location:
Via zoom
Event Time:
Tuesday, May 27, 2025 | 2:00 pm - 3:00 pm
Event Location:
This seminar will only be available on zoom
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2025-05-27T14:00:00
2025-05-27T15:00:00
Building the world’s first open-source quantum computer
Event Information:
Abstract:
As quantum computers transition from academic labs to the larger world, we are faced with the question about how best to shape the emerging technology and the organizations surrounding it. In this talk I will present Open Quantum Design (OQD), a nonprofit foundation with the goal of developing the world's first open-source full-stack quantum computer based on trapped ions. By releasing both the hardware and software stack under permissive open-source licences, OQD provides a collaborative sandbox accessible to academics, startups, government, policy makers, researchers, students and teachers — allowing the larger community to guide the direction of innovation. I will argue that, in addition to ensuring that emerging quantum computers remain democratic, transparent and accessible, an open-source model could also provide a more robust and high-quality technology that is less dependent on conventional commercial incentives.
Bio:
https://perimeterinstitute.ca/people/roger-melko
Event Location:
This seminar will only be available on zoom
Event Time:
Tuesday, May 27, 2025 | 1:00 pm - 2:00 pm
Event Location:
GEOG 100
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2025-05-27T13:00:00
2025-05-27T14:00:00
From malaria to ChatGPT: the birth and strange life of the random walk
Event Information:
The UBC Department of Mathematics is pleased to announce the Niven & Hugh Morris Lecture, taking place tomorrow (May 27, 2025), in GEOG 100 at UBC.
Abstract:
This engaging public talk will explore the fascinating history and surprising applications of random walks - from mosquito control in the early 20th century to their role in modern artificial intelligence. Dr. Ellenberg is an acclaimed mathematician, author, and speaker known for making complex ideas accessible and inspiring.
The Niven Lecture is an annual event that celebrates graduating mathematics students and welcomes their families and the broader community. It honours UBC alumnus Ivan Niven, a renowned number theorist and beloved expositor whose legacy continues to impact generations of learners.
Bio:
Learn More:
About Dr. Ellenberg: https://people.math.wisc.edu/~ellenberg/ and
Event Location:
GEOG 100
Event Time:
Tuesday, May 27, 2025 | 8:00 am - 10:00 am
Event Location:
BC Cancer Research Agency (675 W 10th Ave, Vancouver, BC V5Z 0B4), Boardroom first floor
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2025-05-27T08:00:00
2025-05-27T10:00:00
Advancing Quantitative Dosimetry SPECT with Open-Source Image Reconstruction, Uncertainty Estimation, and Image Generation Optimization
Event Information:
Abstract:
Over the past decade, radiopharmaceutical therapies have demonstrated considerable potential in cancer treatment. Notably, the success of the NETTER-1 and VISION clinical trials led to FDA approval of Lu-177, a beta-emitting isotope, for treating neuroendocrine tumors in 2018 and prostate cancer in 2022. Coinciding with these advancements, there has been growing interest in exploring treatment outcomes using alternative isotopes like the alpha-emitter Ac-225, which may offer enhanced therapeutic benefits. Many therapeutic isotopes also emit photons that, while not directly contributing to therapy, can be detected using SPECT imaging. This enables concurrent delivery and evaluation of patient absorbed dose: a practice that is well-established in the field of external beam radiotherapy. Although current radiopharmaceutical treatment protocols use a standard "one-size-fits-all" approach whereby all patients receive the same injected activity, it is conjectured that image-based dosimetry can be used to tailor dosimetry on an individual basis and consequently improve treatment outcome. One of the major challenges of dosimetry is minimizing and accounting for the presence of bias and uncertainty in acquired SPECT images.
This thesis contains a collection of studies aimed at improving SPECT image quality and interpretability via improvements and modifications to existing image reconstruction protocols. Chapter 2 of the work describes the development of the open-source medical imaging software PyTomography, which enabled the subsequent innovations of this work. Chapter 3 derives a collimator detector response model for SPECT reconstruction of high energy photons, such as those emitted by the daughters of Ac-225. Chapter 4 outlines a modification to existing reconstruction algorithms to permit uncertainty estimation in medical images and subsequently in image-based dosimetry. Chapter 5 explores the optimal image acquisition and reconstruction parameters for Ac-225 imaging, and Chapter 6 explores Monte Carlo based reconstruction techniques to further improve image quality.
Event Location:
BC Cancer Research Agency (675 W 10th Ave, Vancouver, BC V5Z 0B4), Boardroom first floor
Event Time:
Monday, May 26, 2025 | 11:00 am - 12:00 pm
Event Location:
HENN 318
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2025-05-26T11:00:00
2025-05-26T12:00:00
Family trees for fractional quantum Hall states
Event Information:
Abstract:
The fractional quantum Hall (FQH) effect arises in two-dimensional electron systems in strong magnetic fields and leads to exotic phases of matter with emergent quasiparticles known as anyons. These anyons carry fractional electric charge and exhibit braiding properties that go beyond those of bosons and fermions, allowing them to form building blocks for robust quantum codes. However, key features like their braiding properties are notoriously difficult to observe directly in experiments. One approach to gaining insight into a given FQH state — the "parent" — is to study its relationship to nearby "child" states that emerge when the magnetic field is slightly tuned. In this talk, we will present a new and more general framework for constructing FQH families, which can be applied even when previous methods cannot.
Bio:
Carolyn Zhang received her undergraduate degree from Yale University in 2017 and went on to earn her Ph.D. at the University of Chicago under the supervision of Michael Levin, supported by the NSF Graduate Research Fellowship and the Bloomenthal Fellowship. Since the fall of 2023, she has been a Junior Fellow at the Harvard Society of Fellows. Carolyn loves all activities related to mountains, including running, climbing, and hiking.
Learn More:
Watch Carolyn's videos:
Symmetries: Symmetries 2024: Carolyn Zhang (Harvard)
Anyon Condensation and its applications: https://www.youtube.com/watch?v=r8tGIniUxrg
Anomalies of (1 + 1)D categorical symmetries: https://www.youtube.com/watch?v=hSzBMYEY_q8
Event Location:
HENN 318
Event Time:
Sunday, May 25, 2025 | 1:00 pm - 3:30 pm
Event Location:
HENN 318
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2025-05-25T13:00:00
2025-05-25T15:30:00
Zero-energy Modes in Quantum Field Theories
Event Information:
Abstract:
We discuss three instances where zero-energy or soft modes appear in quantum field theory.
First, we examine massless fermions in a 2+ 1 dimensional system with a spatial boundary, specifically graphene in half-space. Two boundary conditions and their interplay with the discrete and continuous symmetries of the system are analyzed. For doubled fermions, we identify a special case that respects CP T symmetry but breaks Lorentz and conformal symmetry, featuring fermion zero mode edge states. These edge states lead to unconventional representations of scale, phase, and translation symmetries, and enforcing symmetry constraints results in edge ferromagnetism.
Second, we investigate the infrared structure of a massless scalar theory coupled to fermions. We demonstrate the existence of a field theory containing massless scalar particles that mirrors the infrared structure of quantum electrodynamics and perturbative quantum gravity but lacks gauge invariance, internal symmetries, or apparent asymptotic symmetry. Unlike soft photons and gravitons, soft scalars do not decouple from dressed states and are generally produced during interactions of hard dressed particles, though their entanglement is minimal.
Lastly, we develop a novel method to calculate changes in an operator’s expectation value at asymptotic times, relevant to gravitational wave observations, by exploiting its soft limit. We derive a formula for asymptotic in-in observables from the soft limit of five-point amputated response functions. Using this, we re-derive the KMOC formulas for linear impulse and radiated momentum during scattering and provide an unambiguous calculation of radiated angular momentum at leading order. We introduce a causal method of computing classical observables using the Schwinger-Keldysh formalism.
Event Location:
HENN 318