Events List for the Academic Year

Event Time: Wednesday, June 12, 2024 | 8:00 am - 5:00 pm
Event Location:
UBC Scarfe & HEBB buildings
Add to Calendar 2024-06-12T08:00:00 2024-06-14T17:00:00 Dawn VII Meeting (June 12-14) Event Information: We invite you to register for the Dawn VII meeting taking place right here on UBC campus in June, 2024.   Every 2-3 years, the community of physicists working with ground-based gravitational wave (GW) detectors holds a discussion-based “Dawn” meeting to plan for the future of the field.    This year the global ground-based GW community, including experts in GW detector technology, GW astrophysics, multi-messenger astronomy, cosmology, nuclear physics, and tests of general relativity, is converging in Vancouver: Blusson QMI is hosting the Dawn VII meeting June 12-13 in the Scarfe building: https://dawn7.phas.ubc.ca/   You can find a program outline here: https://dawn7.phas.ubc.ca/program/   Dawn VII will be a good introduction to challenges, opportunities, and relevant timescales for astrophysics, nuclear physics, and fundamental physics (including cosmology and tests of general relativity) we can achieve with future GW detectors, as well as the development of enabling detector technologies.    There will also be satellite workshops devoted to GW detector technology (including a workshop on thin-film coatings hosted in Brimacombe), multi-messenger astronomy with GWs, and machine learning for GW analysis (taking place in Hebb) on Friday June 14.    It should be a fun and engaging meeting - we encourage you to register! (Registration is $280, and the conference dinner in the Ponderosa Ballroom the evening of June 12 is $95.)   Best, Jess for the Dawn VII Local Organizing Committee  ------------------------------------------------- *We encourage you to register by May 8th   Event Location: UBC Scarfe & HEBB buildings
Event Time: Friday, June 7, 2024 | 11:00 am - 12:00 pm
Event Location:
BRIM 311
Add to Calendar 2024-06-07T11:00:00 2024-06-07T12:00:00 Many-body localization in the disordered Fermi-Hubbard model Event Information: Abstract:  How isolated quantum systems reach thermal equilibrium is a long-standing question of continuing interest. The absence of equilibration in some systems is also well known, notably Anderson localization in noninteracting systems with quenched disorder.  However, it has only relatively recently been understood that the absence of equilibration can persist in the presence of interactions, dubbed many-body localization.  While most of the theoretical work in this area has focused on spin systems, in which there is just one local degree of freedom, systems with multiple coupled degrees of freedom are of interest, not least because most experimental studies of many-body localization use cold atoms described by the Hubbard model. This talk will review this context and explore the specific case of the disordered Fermi-Hubbard model.  With two coupled local degrees of freedom, charge and spin, how does disorder in one of these influence localization in the other? Writing the Hamiltonian in terms of charge- and spin-specific integrals of motion, we extract time scales associated with charge-charge, spin-spin, and charge-spin coupling and connect these with the growth of entanglement. Event Location: BRIM 311
Event Time: Thursday, May 30, 2024 | 2:00 pm - 3:00 pm
Event Location:
MacLeod 3038 (https://maps.ubc.ca/?code=MCLD)
Add to Calendar 2024-05-30T14:00:00 2024-05-30T15:00:00 Next-Generation Microcombs for Compact Optical Frequency Division Systems Event Information: Dear colleagues,We invite you to the next SSCS Vancouver Seminar on Thursday, May 30th, at 2 pm by Prof. Kerry Vahala from Caltech. Kerry is a world authority on frequency combs. Please remember to mark your calendar! Abstract: Optical frequency division (OFD) enables transfer of stability from references such as atomic transitions and optical cavities to microwave and radio-frequency signals.  Enabled by self-referenced frequency combs, the most accurate clocks (optical clocks) and lowest phase-noise microwave signal sources are based upon this method. In recent years, a miniature chip-based comb (microcomb) is being studied for creation of compact OFD systems.  I will review the physical principles of microcomb operation along with recently demonstrated microcomb devices that mode lock by formation of femtosecond pulse pairs.  Finally, a high-performance microwave signal source is described wherein microcombs implement the method of 2-point OFD using a compact cavity reference.Biography: Kerry Vahala is Professor of Applied Physics at Caltech and holds the Jenkins Chair in Information Science and Technology. His research on chip-based high-Q optical resonators and related nonlinear optical devices has advanced miniature frequency and time systems, microwave sources, parametric oscillators, astrocombs and gyroscopes. Vahala also made early contributions to the subject of cavity optomechanics and demonstrations of chip-based devices to cavity QED phenomena. A member of the National Academy of Engineering and Fellow of the IEEE and Optica, he received the IEEE Sarnoff Medal for research on quantum-well laser dynamics, the Alexander von Humboldt award and MPQ Distinguished Scholar Award for work on ultra-high-Q optical microcavities, a NASA achievement award for application of microcombs to exoplanet detection, and the Optica Paul F. Forman Team Engineering Excellence Award for a 2-photon optical clock. Vahala is the Executive Officer of the Department of Applied Physics and Materials Science at Caltech.   Event Location: MacLeod 3038 (https://maps.ubc.ca/?code=MCLD)
Event Time: Thursday, May 30, 2024 | 11:00 am - 12:30 pm
Event Location:
HENN 318
Add to Calendar 2024-05-30T11:00:00 2024-05-30T12:30:00 Efficient field theories for big data experiments Event Information:   *This talk is presented live in HENN 318 and via Zoom: Meeting URL:     https://ubc.zoom.us/j/63645767535?pwd=ocFqc2BzhwbnSNoGY7iabbjlvxVXTM.1 Meeting ID:     636 4576 7535 Passcode:    147999  Bio:Dave Sutherland is a theoretical physicist. After completing his PhD in 2016 at the Cavendish laboratory in Cambridge, he worked as a postdoc in UC Santa Barbara, and a Marie Skłodowska-Curie COFUND fellow at INFN Trieste, before moving to Glasgow as a lecturer in 2022. He has worked on various aspects of model building, effective field theory, amplitudes, and their applications to phenomenology. Abstract:In particle physics, we have lots of data, but we are unsure exactly what to look for within it. I will show how simple principles from field and scattering theory can help guide this search, maximize our chance of a fundamental discovery, and guarantee that we understand the nature of electroweak symmetry breaking in the coming decades.  Links: See his University of Glasgow faculty webpage here: University of Glasgow - Schools - School of Physics & Astronomy - Our staff - David Sutherland Event Location: HENN 318
Event Time: Friday, May 24, 2024 | 10:00 am - 12:00 pm
Event Location:
Henn 318
Add to Calendar 2024-05-24T10:00:00 2024-05-24T12:00:00 Negative Lambda Quantum Cosmology Event Information: Abstract: We present a model of quantum cosmology based on anti-de Sitter/conformal field theory (AdS/CFT) holography. The spacetimes in our construction are time-symmetric, big-bang/big-crunch cosmologies with a negative cosmological constant $\Lambda$. In the simplest version of our model the cosmology lives inside a spatially finite bubble within an otherwise empty AdS spacetime. By studying the thermodynamic and geometric properties of this spacetime, we provide evidence that the ``bubble of cosmology'' spacetime has a well-defined dual CFT description.   It is also desirable to have a cosmology which is globally homogeneous and isotropic. We present an upgraded model in which this is the case.  Although a homogeneous cosmology is not asymptotically AdS and hence cannot be described directly by AdS/CFT, the time-reflection symmetry of the spacetime allows us to perform an analytic continuation, following which the spacetime is an asymptotically AdS Euclidean wormhole. If we assume that the cosmology is spatially flat a second analytic continuation obtains a Lorentzian traversable AdS wormhole. The AdS wormhole spacetimes can be described using holography: they are dual to a pair of three-dimensional CFTs coupled via a four-dimensional theory.  We explain how an anomalously large amount of negative energy can support the traversable wormhole, and we begin to populate the holographic dictionary relating observables in the wormhole/cosmology to observables in the microscopic theory. Finally we show that time-dependent scalar fields naturally enable these cosmologies to contain a period of accelerated expansion, suggesting that our $\Lambda<0$ models could ultimately provide the framework for a fully microscopic description of our universe.   Event Location: Henn 318
Event Time: Thursday, May 23, 2024 | 2:00 pm - 4:00 pm
Event Location:
Henn 309
Add to Calendar 2024-05-23T14:00:00 2024-05-23T16:00:00 A study of sporadic pulsars and radio transients with the CHIME telescope Event Information: Lay abstract: Pulsars are the remnants of massive stars. Their rapid and precise rotation allows us to use them as tools to test many theories of physics. Pulsars come in many flavours; some are sporadic and only emit radio waves occasionally. This thesis uses the Canadian Hydrogen Mapping Experiment (CHIME) to study pulsars of all flavours. First, I developed a new processing pipeline so that we can fully utilise the capabilities of CHIME/Pulsar. Then, I create a technique, LuNfit, to characterise the single pulses of pulsars. I then apply LuNfit to 35 pulsars with a 477-hour CHIME/Pulsar observation campaign. Finally, I discovered a new long-period transient, CHIME J0630+25, with a period of 421 seconds.  This marks only the fourth object in this new class. Their nature remains unknown, but we speculate that CHIME J0630+25 is likely a white dwarf or a neutron star. Event Location: Henn 309
Event Time: Tuesday, May 14, 2024 | 1:00 pm - 2:00 pm
Event Location:
BRIM 311
Add to Calendar 2024-05-14T13:00:00 2024-05-14T14:00:00 Graphene multilayers: from unconventional superconductors to quantum devices Event Information: Abstract: Crystalline graphene multilayers present a rich playground to explore correlated electronic phenomena in a tunable and ultra-clean setting. For instance, Bernal bilayer graphene and rhombohedral trilayer graphene host multiple symmetry-broken metallic phases at low temperature, as well as unconventional superconductors with different pairing symmetries. The rich phase diagram of these systems can further be tuned through proximity to WSe2, which induces spin-orbit coupling in the graphene layers and leads to a dramatic enhancement of superconductivity that remains poorly understood. I will first discuss the lessons learned from our theoretical exploration of graphene multilayers with induced spin-orbit coupling, focusing on various types of magnetic and inter-valley coherent ground states and their possible connections to superconductivity. I will then outline a recipe to engineer topological superconductivity in graphene multilayers using gate-defined Josephson junctions. Such a platform provides a promising alternative to traditional architectures for Majorana zero-modes due to its purity, gate tunability and atomically thin nature.  Speaker Bio: Étienne Lantagne-Hurtubise completed his PhD at UBC, and worked at QMI with Professor Marcel Franz. He is currently a postdoctoral fellow at Caltech. Event Location: BRIM 311
Event Time: Monday, May 13, 2024 | 12:30 pm - 2:30 pm
Event Location:
TRIUMF Theory Room, 4004 Wesbrook Mall and zoom; https://ubc.zoom.us/j/68938408525?pwd=MVBBK05ZQWdCK2tJKzNGUXZaazJhdz09 Passcode: 959424
Add to Calendar 2024-05-13T12:30:00 2024-05-13T14:30:00 Probing Beyond Standard Model Physics Through Ab Initio Calculations of Exotic Weak Processes in Atomic Nuclei Event Information: "Exotic weak decays offer a unique way to probe physics beyond the Standard Model in a low-energy regime using the atomic nucleus as a window to complement the high-energy searches done at particle accelerator facilities. However, in order to extract the relevant physics parameters from experimental observations, inputs from nuclear theory are required.   The hypothetical neutrinoless double beta decay has gathered a lot of interest, as its observation would answer many standing questions in particle physics. First, it would unveil fundamental properties of the most abundant yet most elusive massive particle: the neutrino. A simple observation of this decay would imply the neutrino to be Majorana, meaning that it is its own antiparticle, as well as give insight into its absolute mass. Furthermore, the existence of this decay would explain the matter/antimatter asymmetry of the universe.   In order to extract the neutrino mass and potential couplings to more exotic mechanisms, as well as compare sensitivities of experiments using different isotopes, the nuclear matrix element must be obtained from nuclear theory. Unfortunately, the different models that have historically been used to compute this quantity have shown a large spread with no means of quantifying their respective uncertainties, greatly hindering the experimental precision.   In this thesis, we use recent advances in ab initio methods, which profit from the rapid increase in computational power to calculate nuclear observables directly from the interaction between the nucleons. In particular, we use the ab initio valence-space in medium similarity renormalization group method to compute the matrix element of all relevant candidate isotopes for experimental searches. We further develop a new machine learning emulator that greatly increases the speed of calculations. Using this emulator, we  probe the full input parameter space of the calculation to give the first statistical uncertainty on the matrix element.   Our results show smaller values than previous models and are consistent with other ab initio methods. This provides a much tighter constraint than the spread coming from previous models, greatly clarifying the picture for both current and future experimental searches of the decay. “ Event Location: TRIUMF Theory Room, 4004 Wesbrook Mall and zoom; https://ubc.zoom.us/j/68938408525?pwd=MVBBK05ZQWdCK2tJKzNGUXZaazJhdz09 Passcode: 959424
Event Time: Friday, May 10, 2024 | 9:00 am - 11:00 am
Event Location:
Henn 309 and Zoom, https://ubc.zoom.us/j/69190854282?pwd=amdGR3ovSnhDc0lSaXR6bzNuTkZYQT09
Add to Calendar 2024-05-10T09:00:00 2024-05-10T11:00:00 Classical descriptions of quantum computations: Foundations of quantum computation via hidden variable models, quasiprobability representations, and classical simulation algorithms Event Information: [abstract] Quasiprobability representations serve as a bridge between classical and quantum descriptions of physical systems. In these representations, nonnegativity allows for a probabilistic interpretation, aligning the description with classical physics.  However, the capacity to model quantum systems hinges on the use of negative quasiprobabilities. Accordingly, negativity is considered a hallmark of genuinely quantum behaviour. This principle has been applied to quantum information processing where negativity in the Wigner function is necessary for a quantum computational advantage. This is demonstrated by an efficient classical simulation algorithm for quantum computations in which all components of the computation remain nonnegative.   However, when constructing quasiprobability representations for quantum computation to which this statement applies, a marked difference arises between the cases of even and odd Hilbert space dimension. We find that Wigner functions with the properties required to describe quantum computation do not exist in any even dimension. We establish that the obstructions to the existence of such Wigner functions are cohomological.   In order to recover the properties required for classical simulation of quantum computation in any dimension, some constraints that traditionally define a Wigner function must be relaxed. We consider several examples of these generalized quasiprobability representations, and we find that when sufficiently general representations are admitted, no negativity is required to represent universal quantum computation.  The result is a hidden variable model that represents all elements of universal quantum computation probabilistically. Since this model can simulate any quantum computation, the simulation must be inefficient in general. However, in certain restricted settings, the simulation is efficient, allowing for a broader class of magic state quantum circuits to be efficiently classically simulated than those covered by the stabilizer formalism and Wigner function methods.   With this hidden variable model, we present a formulation of quantum mechanics that replaces the central notion of state, as a complex vector or density operator, with a bit string. This formulation applies to universal quantum computation, and hence all finite-dimensional quantum mechanics. Thus, we present a surprising response to Wheeler’s "It from Bit" challenge. Alongside coherence, entanglement, and contextuality, this provides a new approach to characterizing quantum advantage. Event Location: Henn 309 and Zoom, https://ubc.zoom.us/j/69190854282?pwd=amdGR3ovSnhDc0lSaXR6bzNuTkZYQT09
Event Time: Wednesday, May 1, 2024 | 12:00 pm - 2:00 pm
Event Location:
QMI 188 (2355 East Mall)
Add to Calendar 2024-05-01T12:00:00 2024-05-01T14:00:00 Emergent optical and electronic properties in atomically thin rhombohedral-stacked transition metal dichalcogenides Event Information: Abstract: Rhombohedral(R)-stacked TMD means the neighbouring layers are oriented in the same direction, which can be obtained through either chemical synthesis or artificial stack with a small twist. The investigation into how the stacking order determines the properties of TMD homobilayers is crucial for understanding the exotic physics observed in two-dimensional semiconductors. Here we use various optical spectroscopy techniques to explore the emergent excitonic and correlated phenomena in both homogeneous and twisted TMD homobilayers of rhombohedral stacking. Specifically, we observe a spontaneous electrical polarization arising from the asymmetric interlayer-coupling-induced Berry phase in R-stacked MoS2 bilayer. Utilizing this polarization, we achieve an efficient and scalable photovoltaic effect in a Gr/R-MoS2/Gr heterostructure. By employing non-degenerate pump-probe photocurrent spectroscopy, we disentangle the competition between thermal and electronic effects, extracting a 2ps intrinsic photocurrent speed. More importantly, the out-of-plane electrical polarization in R-stacked MoS2 can be switched through in-plane sliding motion, which is referred to as sliding ferroelectricity. By harnessing the coupling between electronic polarization and excitonic effects, we demonstrate an optical method to probe the domain wall motion in both R-stacked MoS2 homo-bilayer and tri-layer.  Finally, we report the discovery of a series of correlated insulating states at both integer and fractional fillings, arising from Γ-valley flat bands, in a small-angle twisted MoSe2 homo-bilayer. We observe a Mott-insulator state instead of a semi-metal on the half-filled honeycomb lattice, in contrast to the theoretical prediction based on continuum model. The observed phenomenon is consistent with the picture of semi-metal to insulator transition at large U/t limit. Our exploration on the moire homo-bilayer in rhombohedral stacking offers a new opportunity to simulate the Mott-Hubbard physics with spin SU (2) symmetry. Event Location: QMI 188 (2355 East Mall)
Event Time: Monday, April 29, 2024 | 10:00 am - 12:00 pm
Event Location:
14th floor meeting room, BC Cancer Research Institute
Add to Calendar 2024-04-29T10:00:00 2024-04-29T12:00:00 An analysis of imaging and biological effects impacting theranostic dosimetry using radiopharmaceutical pairs Event Information: Abstract:   Radiopharmaceutical therapy (RPT) is a safe and effective cancer treatment using alpha or beta emitting radiopharmaceuticals that specifically target cancer cells to selectively destroy cancer tissue while sparing healthy cells. Treatment can be personalized on a patient-by-patient basis using dosimetry to determine suitable administered activities for subsequent treatment cycles. Dosimetry requires obtaining quantitative single photon emission computed tomography (SPECT) images which can only be done using gamma emitting radioisotopes.   Not all therapeutic radioisotopes are suitable for SPECT imaging. In such cases, it may be necessary to use an imaging surrogate to predict the radiation dose from the therapeutic isotope, either pre-therapy or during combination RPT. However, these methods may introduce inaccuracies into the dosimetry estimate. This dissertation aims to investigate some “theranostic pair” radiopharmaceuticals and determine if these pairs may be suitable for theranostic dosimetry.   In addition to a comprehensive literature review of theranostic dosimetry and the validity of multiple theranostic pairs used clinically and pre-clinically, three Monte Carlo based simulation studies are performed:     - First, an investigation into the theranostic pair 177Lu (a beta/gamma emitter) and 90Y (a beta emitter) to determine if Bremstrahhlung photons emitted by 90Y reduce the accuracy of quantitative SPECT imaging of 177Lu   - Then, simulations of 225Ac (an alpha emitter) and 177Lu within prostate cancer cells were performed and used to create nucleus absorbed dose kernels which were convolved with multicellular tumour maps of varying morphologies (i.e. hypoxic, necrotic, and normoxic tumour phenotypes) to assess the absorbed dose distribution differences between particulate radiation from 225Ac and 177Lu on a microscopic scale   - Finally, the proposition of a novel method using 99mTc (a gamma emitter) to improve bone marrow dosimetry is discussed and tested. Bone marrow dosimetry during RPT for prostate cancer with 177Lu labelled pharmaceuticals is extremely challenging, and we propose using 99mTc-sulfur colloids to assist in the determination of bone marrow location during imaging and subsequently use 177Lu for bone marrow dosimetry, which requires simultaneous SPECT imaging of 177Lu and 99mTc.  We test the feasibility of this and suggest additions to clinical scatter correction methods to reduce the impact of photon contamination from 177Lu on 99mTc images.   Event Location: 14th floor meeting room, BC Cancer Research Institute
Event Time: Thursday, April 18, 2024 | 10:00 am - 11:00 am
Event Location:
BRIM 311
Add to Calendar 2024-04-18T10:00:00 2024-04-18T11:00:00 Anomalous Hall Crystals in Graphene: interaction-driven Chern bands at zero magnetic field Event Information: Abstract: Recent experiments have discovered that pentalayer-graphene subject to a moire superlattice spontaneously breaks time-reversal, resulting in a quantized anomalous Hall effect at zero magnetic field. At fractional filling, the material exhibits a zero-field fractional quantum Hall effect. In contrast to other moire-materials, the origin of Chern bands in this material is not so clear. I will present a theoretical picture in which Chern bands arise from an “anomalous Hall crystal” stabilized primarily by interactions. So far this picture is supported mainly by mean-field calculations, so I’ll conclude with some open questions about how the Hall crystal could be verified. Speaker Bio: Michael Zaletel is an Associate Professor of Physics and theAllison and Thomas Schneider Chair at UC Berkley. Event Location: BRIM 311
Event Time: Friday, April 12, 2024 | 12:00 pm - 2:00 pm
Event Location:
https://lbnl.zoom.us/j/93893398617?pwd=dmlKMCtvaGE3VnkwTDZEdW5xK3VMdz09 Meeting ID: 938 9339 8617 Passcode: 638333
Add to Calendar 2024-04-12T12:00:00 2024-04-12T14:00:00 Advances in decay spectroscopy of 160Gd and developments for transfer experiments using radioactive isotope beams Event Information: [Abstract] The structure of the atomic nucleus can rapidly evolve from a spherical shape into one with significant deformation as the number of protons and neutrons change within the nucleus. These exotic nuclei present the opportunity to study the evolution of the nuclear force via the resulting nuclear structure exhibited by the nucleus. In this work, the results of nuclear structure experiments on three isotopes are presented. These experiments, all performed at the TRIUMF-ISAC radioactive beam facility, help to improve understanding of the evolution of nuclear structure from single-particle to collective excitations in nuclei. The structure of the highly-deformed 160Gd has been studied via the beta-decay of 160Eu using the GRIFFIN spectrometer. New measurements of spectroscopic information and lifetimes of excited-states has shed new light on the structure of K=4+ deformed bands located in this nucleus and supports these are being hexadecapole phonon bands. Lifetime measurements in 160Gd also show the 1999 keV state as having positive, not negative, parity. This result raises questions about the established structure of the beta-decaying states in the parent 160Eu.Development and analysis in support of transfer reaction experiments at TRIUMF-ISAC was performed. Upgrades to the TRIFIC ionization chamber used in conjunction with the TIGRESS gamma-ray spectrometer are discussed. Experimental data from (d,p) neutron transfer reactions on the stable 86Kr and the radioactive 93Sr nucleus is presented here. In the resulting 87Kr, single-particle structure analysis of this data shows the evolution of neutron orbitals directly above the N=50 neutron shell closure. The structure of 94Sr was observed via (d,p) reactions on 93Sr. This experiment is the first ever population of 94Sr via a (d,p) reaction, and spectroscopic factors and angular distributions for a number of excited-states are first reported. The transfer data analysis on 86Kr and 93Sr is also in support of a larger experimental campaign using the Surrogate Reaction Method to experimentally constrain neutron capture cross-sections on unstable nuclei and briefly discussed here.   Event Location: https://lbnl.zoom.us/j/93893398617?pwd=dmlKMCtvaGE3VnkwTDZEdW5xK3VMdz09 Meeting ID: 938 9339 8617 Passcode: 638333
Event Time: Thursday, April 11, 2024 | 4:00 pm - 5:00 pm
Event Location:
HENN 202
Add to Calendar 2024-04-11T16:00:00 2024-04-11T17:00:00 From Antarctica to PHAS: Lessons on inclusive leadership and collaboration in STEM Event Information: Abstract:I will share my reflections upon my four-year journey in the Homeward Bound Program, a leadership training for women in STEM that culminated in an expedition to Antarctica. This will be an interactive session geared towards all members of PHAS, including undergraduate/graduate students, postdocs, faculty and staff. You will learn more about the wildlife and landscape of the Antarctic peninsula, and what I did in the expedition with women leaders in various STEM disciplines. Most importantly, I will use this opportunity to gather your ideas on how to make our department and discipline more inclusive and welcoming for all. Bio: Allison Man is an Assistant Professor in the Department of Physics & Astronomy at UBC. Her  research area is galaxy evolution. She studies how massive galaxies assemble their stars in the first few billion years of the cosmic history. She uses gravitational lensing to obtain a resolved view of distant galaxies — they are otherwise too faint and too small to be observed with current telescopes.  On a lighter note from discussions on her Homeward bound experience, she has described a new-found delight in penguins, Antarctic ocean swimming and learning from others in multidisciplinary STEM fields to the Fine Arts!  Learn More: Read this article about Allison being chosen as a participant on the 5th Homeward Bound Program Check out the Homeward bound website Learn about the UBC Extragalactic Astrophysics Group and what they study on Allison's faculty webpage Event Location: HENN 202
Event Time: Wednesday, April 10, 2024 | 2:00 pm - 3:00 pm
Event Location:
BRIM 311
Add to Calendar 2024-04-10T14:00:00 2024-04-10T15:00:00 Dissipation driven dynamical topological phase transitions in two-dimensional superconductors Event Information: Abstract: By quenching the interaction strength, we induce and study a topological dynamical phase transition between superconducting phases of a planar fermionic model. Using the Lindblad Master Equation approach to account for the interactions of Bogoliubov quasiparticles among themselves and with the fluctuations of the superconducting order parameter, we derive the corresponding relaxation dynamics of the order parameter. To fully characterize the phase transition, we also compute the fidelity and the spin-Hall conductance of the system. Our approach provides us crucial informations for experimental implementations, such as the dependence of the critical time on the system-bath coupling. Speaker Bio: Domenico Giuliano has received his Ph. D. in 1998 from the Università di Napoli (Naples University) “Federico II” – Italy. During his Ph. D. he has spent six months at Stanford University, under the supervision of Prof. Robert Laughlin. After graduating, he moved back to Stanford, on a two-year post-doc appointment, supervised again by Prof. Laughlin. After that, he has spent two more years in Napoli as a post-doc research associate under the supervision of Prof. Arturo Tagliacozzo, in 2003 he has become a university researcher at the University of Calabria, in Soutern Italy. From year 2020 he is an associate professor of theorical physics at the same university. In the past, he has been visiting several times the department of Physics at the University of British Coumbia, on a long-lasting scientific collaboration with Prof. Ian Affleck and his group. Domenico’s main research interest are in theoretical condensed matter. They include: Fractionalization of quantum number and fractional statistics; Low-dimensional correlated system, including one-dimensional Luttinger liquids; Topological insulators and topological superconductors; Kondo effect and its applications; Quantum phase transitions. Event Location: BRIM 311
Event Time: Monday, April 8, 2024 | 4:00 pm - 5:00 pm
Event Location:
HENN 318
Add to Calendar 2024-04-08T16:00:00 2024-04-08T17:00:00 Pushing the frontiers of galaxy formation modeling with multi-scale simulations and machine learning Event Information: Abstract: Supermassive black holes (SMBHs) in Active Galactic Nuclei (AGN) play a key role in the formation of galaxies and large-scale structure, but the triggering and impact of AGN feedback across scales and the origin of the observed SMBH–galaxy connection remain major open questions owing to the multi-scale and multi-physics nature of the problem. AGN feedback can also profoundly affect the properties and spatial distribution of baryons on scales that contain a large amount of cosmological information.  Current and upcoming cosmological surveys will provide unprecedented data to constrain the fundamental cosmological parameters, but uncertainties in galaxy formation physics remain a major theoretical obstacle to extract information from cosmological experiments.  In this talk, I will present new simulation techniques that are pushing the frontiers of galaxy formation modeling towards (1) the smallest scales, developing physically predictive models of SMBH accretion and feedback explicitly at sub-pc resolution in a full cosmological context to interpret a plethora of galaxy and AGN observables, and (2) the largest scales, developing thousands of large-volume simulations exploring a wide range of sub-grid feedback implementations to train robust machine learning algorithms that can maximize the extraction of information from cosmological surveys while marginalizing over uncertainties in galaxy formation physics.  I will demonstrate the feasibility of these orthogonal approaches to address fundamental problems and discuss their potential to significantly advance the fields of galaxy evolution and cosmology. Bio: Dr. Daniel Anglés-Alcázar is an Assistant Professor of Physics at the University of Connecticut, specializing in Computational Galaxy Formation.    Learn More: See his research group website here Read more about his research interests here     Event Location: HENN 318
Event Time: Monday, April 8, 2024 | 10:00 am - 12:30 pm
Event Location:
UBC plaza area between the UBC Bookstore (6200 University Blvd) and the UBC Alumni Centre (6163 University Blvd)
Add to Calendar 2024-04-08T10:00:00 2024-04-08T12:30:00 Partial Solar Eclipse Viewing Event Event Information: Come and join us for this partial eclipse viewing event! PHAS ASTRO faculty and students will be on-site to share information and to lend you eclipse glasses to view the eclipse. UBC Partial Eclipse Event:Date: Monday, April 8th, 2024Time: 10:00am – 12:30pmLocation: in the plaza area between the UBC Bookstore (6200 University Blvd) and the UBC Alumni Centre (6163 University Blvd) Who will be there: Department of Physics & Astronomy ASTRO Faculty and students will be your guides to what is happening during this eclipse, and how to view it safely! Equipment: eclipse glasses, two solar telescopes and edible pin-hole cameras for kids!   Want to learn more? Check out the Discover the Universe website which has lots of resources on the April eclipse   Read the Canadian Space Agency site for more eclipse information View the NASA site for more! Event Location: UBC plaza area between the UBC Bookstore (6200 University Blvd) and the UBC Alumni Centre (6163 University Blvd)
Event Time: Friday, April 5, 2024 | 3:00 pm - 4:00 pm
Event Location:
HENN 201
Add to Calendar 2024-04-05T15:00:00 2024-04-05T16:00:00 The International Liquid-Mirror Telescope Event Information: Abstract:  A unique and novel optical telescope has recently started operating. Perched on a mountaintop in the Indian Himalayas, the ILMT uses a low-cost 4-metre rotating parabolic mirror, surfaced with a thin reflecting film of liquid mercury, to collect and focus light. The telescope views objects as they pass overhead, compensating for the Earth's rotation by continuously scanning its electronic camera. In a single night it is able to survey an area of sky that is 250 times larger than the full moon. The ILMT observes the same strip of sky night after night, looking for anything that changes, including asteroids, supernovae, variable stars, active galaxies, quasars and space debris. I will give an overview of the project and describe the technology that made it possible. Bio: Paul Hickson is a professor of Astronomy at UBC.  Learn More: Find out more on Paul's faculty webpage here Read about the International Liquid Mirror Telescope (ILMT) telescope from this UBC Science article here Watch Paul talk about the ILMT telescope on Youtube here Here's another article about the 4 metre International Liquid Mirror Telescope Event Location: HENN 201
Event Time: Thursday, April 4, 2024 | 4:00 pm - 5:00 pm
Event Location:
HENN 202
Add to Calendar 2024-04-04T16:00:00 2024-04-04T17:00:00 The Art of the Impossible: Probing Challenging Higgs Channels at the LHC Event Information: Abstract: The search for the Higgs boson was central to the conception and design of the LHC detectors. However, measurements of the Higgs coupling to the second and third-generation quarks were regarded as extremely challenging and, in some cases, impossible.  Scientific ingenuity and original thought have allowed ATLAS and CMS to probe the coupling of the Higgs boson to quarks. I will discuss techniques (including machine learning) used to achieve this and provide a brief perspective on future directions. Bio: Heather attended the University of Cape Town in South Africa from 1999-2005 where she obtained a BSc, BSc (Hons) and then a MSc in Physics. She then attended the California Institute of Technology and obtained her Ph.D. in Physics in 2011. She then worked at CERN as a Research Fellow and Research Staff Scientist from 2011-2017 before moving to LBNL as a Divisional Fellow in 2017. Heather joined the UC Berkeley faculty as assistant professor in 2019. She received the IUPAP C11 Young Scientist Prize in 2018. She is currently serving in a high-level management role within the ATLAS experiment as the Data Preparation Coordinator. Research Interests: I am an experimental particle physicist working on the ATLAS experiment at the Large Hadron Collider (LHC) just outside Geneva in Switzerland. I have broad interests in particle physics, but the primary focus of my research is the Higgs boson -- the most recently discovered elementary particle, the only known elementary scalar of nature and the final piece of the remarkably successful Standard Model. However, this discovery leaves many important questions unanswered and uncovers further questions. The Higgs is not just another particle. It is profoundly different from all other elementary particles, relates to the most obscure sectors of the Standard Model and is linked to some of the deep questions, so it might prove to be a portal to find new physics. I study the properties of the Higgs boson and, in particular, how it interacts with different types of quarks, including top, bottom and charm quarks.  Other research interests include the development of track reconstruction algorithms, silicon detectors and algorithms for quantum computers. A theme throughout my research is applications of machine learning. I collaborate with Professors Marjorie Shapiro and Haicheln Wang at UC Berkeley and with scientists in the ATLAS group at Lawrence Berkeley National Laboratory (LBNL). The ATLAS group at LBNL works on a broad range of physics topics from measurements to the Standard Model to searches for new physics. The group also plays important roles in the operation of the ATLAS pixel detectors, design and construction of upgraded silicon detectors, software development for improved detector performance, event generation, simulation, and computing. Learn More: See Heather's UC Berkely faculty website page here: Heather Gray | Physics (berkeley.edu) Learn more about the Gray Research Group here: Gray Research Group | Physics (berkeley.edu) Event Location: HENN 202
Event Time: Thursday, April 4, 2024 | 10:00 am - 11:00 am
Event Location:
BRIM 311
Add to Calendar 2024-04-04T10:00:00 2024-04-04T11:00:00 Electrons in twisted layers: design, surprise, and a new set of eyes Event Information: Abstract: The goal of building a quantum computer has lead to rapid advances in experiments that allow for high-precision dynamical control of quantum systems at the single qubit level.  However, a major challenge in harnessing the power of these devices is in understanding how best to control noise.  In particular, many interesting phases of matter, including topological phases, that exist in closed quantum systems are not stable at finite temperature, suggesting that they are particularly sensitive to the kinds of open-system noise present in such devices.  Quantum error correction protocols can be used to rectify this, but these involve non-local processes.  In this talk, I will explore approaches to stabilizing symmetry-protected topological order at arbitrarily long times in 1 dimension using local open-system dynamics.  I will show that this can be done when the noise is of a particular type relevant to Rydberg atom arrays, known as biased erasure noise, and comment on the implications of these results for possible steady-state phases of open quantum systems. Speaker Bio: Fiona Burnell is a UBC alumnae and an associate professor at the University of Minnesota.  Her research interests include understanding how topology and symmetry dictate the possible phases of matter that can be found in nature,  studying how and when quantum dynamics can result in systems evading their naive thermal equilibrium, and contemplating experiments that can reveal patterns of quantum entanglement in many-body systems. Event Location: BRIM 311