Events List for the Academic Year

Event Time: Friday, May 17, 2019 | 2:00 pm - 3:30 pm
Event Location:
MACLEOD 418, 2335 Engineering Lane
Add to Calendar 2019-05-17T14:00:00 2019-05-17T15:30:00 CM Seminar: Vector beams, high harmonic generation and THz solenoidal magnetic fields Event Information: Abstract:  We use intense vector beams to generate high harmonics or to create solenoidal currents in solids or gases.  We create circularly polarized harmonics and we predict THz magnetic fields reaching the scale that is only available at user facilities. Event Location: MACLEOD 418, 2335 Engineering Lane
Event Time: Thursday, May 16, 2019 | 10:00 am - 11:30 am
Event Location:
Hennings 318
Add to Calendar 2019-05-16T10:00:00 2019-05-16T11:30:00 The Physics Course Laboratory Report as a Rhetorical Act Event Information: The field of science education has paid considerable attention to what students should write in their lab reports, but comparatively little attention has been given the laboratory report writing as a rhetorical activity—one in which writers attempt to communicate with a particular audience for a specific purpose. This is unfortunate, since labs remain students’ primary experience with scientific writing in the undergraduate science curriculum—especially in mathematically-heavy fields such as physics. In many undergraduate courses, lab report writing assignments tend to reinforce misunderstandings about scientific communication students often bring from high school, rather than helping students develop a more sophisticated and effective understanding of effective scientific communication. This talk invites us to reconsider the experience of the undergraduate physics lab report—both for students as writers and instructors as readers. Relevant Publication: Inquiry-based writing in the laboratory course   Other talks by Cary while he is here   Public Talk: Text Recycling in Scientific Writing Cary Moskovitz, Director, Writing in the Disciplines, Thompson Writing Program, Duke University May 15, 10:00 - 11:30 am MSL 102 Text recycling (often called “self-plagiarism”) is the reuse of textual material from existing documents in a new text without the use of quotation marks or other means of identifying the reused material as such. While text recycling has long been common practice in some STEM fields, the recent adoption of digital plagiarism detection tools by scientific journals has made text recycling the subject of increasing controversy and ethical debate. Some researchers and editors argue that text recycling is inherently unethical or otherwise problematic. Others, including organizations such as the American Psychological Association and the Committee on Publication Ethics (COPE), state that some uses of text recycling are acceptable and, in limited circumstances, desirable—particularly in Introduction and Methods sections. Although text recycling is an increasingly important ethical issue in scientific communication (even listed as a priority for RCR training in an ORS-funded study), it is rarely addressed in the ethical training of researchers or in scientific writing textbooks or websites. ***For full details and to register for the text recycling talk: https://events.ctlt.ubc.ca/events/text-recycling-in-scientific-writing/   Lunch Chat: Volunteer Expert Readers: The Duke Reader Project Cary Moskovitz, Director, Writing in the Disciplines, Thompson Writing Program, Duke University May 15, ~11:45 am - 1:30 pm CHEM D213 Volunteer Expert Readers (VER) is a novel approach to providing undergraduates with feedback on writing assignments via an otherwise untapped educational resource: university alumni and employees who normally play no role in the institution's educational mission. In the VER approach, students are paired with volunteers whose backgrounds make them suitable readers for specific writing assignments. Having the opportunity to discuss their work in progress with experts in the field increases students’ engagement in class writing assignments. The feedback also helps students learn to anticipate the needs and expectations of readers, and to revise their writing to make it more effective for the intended audience.  By participating as readers, members of the broader college community can play a direct role in helping students develop the communication and reasoning skills that are so important for their success in both professional and civic life. ***To register for the lunch chat, please email jandciu@science.ubc.ca Relevant Publications: Reader Experts Help Students Bring the Write Stuff Volunteer Expert Readers for STEM Student Writers  The Duke Reader Project: Engaging the University Community in Undergraduate Writing Instruction   Event Location: Hennings 318
Event Time: Saturday, May 11, 2019 | 10:00 am - 2:00 pm
Event Location:
Beaty Biodiversity Museum and various locations on campus
Add to Calendar 2019-05-11T10:00:00 2019-05-11T14:00:00 UBC Science Rendezvous Festival Event Information: Join us for The University of British Columbia’s 2019 Science Rendezvous festival. Science Rendezvous is an annual festival held across Canada showcasing the Art in Science. Science Rendezvous theme this year is “STEAM big” encouraging new exciting collaborations between scientists and artists, science and art. On Saturday May 11 (10 AM – 2 PM) race across the University to complete our Science Chase! From the Old Barn Community Centre to the Department of Chemistry, intrepid visitors will race across campus and experience the power of STEAM! Check out art-science performances (poetry and 3D-printed violin), take a ride on a hovercraft, discover micro-organisms in the pond, and learn about the tectonic forces that shape and alter our world. Make it through all the explosions, workshops, and hands-on experiments to emerge a science victor! Cool prizes awaits – including coupons for free summer camp spots, circuit kits, dinosaur bone samples, and Science Rendezvous T-shirts! For more information, including participating partners and activity descriptions, visit the event website: https://www.sciencerendezvous.ca/event_sites/ubc/ Event Location: Beaty Biodiversity Museum and various locations on campus
Event Time: Friday, May 10, 2019 | 11:00 am - 12:30 pm
Event Location:
Orchard 1001
Add to Calendar 2019-05-10T11:00:00 2019-05-10T12:30:00 How do you teach students to evaluate their answers to physics problems? Event Information: This is a public talk as part of the annual UBC Physics and Astronomy Education Research Group's Open Retreat. Abstract: Physicists need ways to evaluate our solutions to the problems we consider – the universe has no solution manual! This “solution evaluation” is just one aspect of physics sensemaking. To help students become more powerful physics sensemakers and build a habit of evaluating their solutions, my research team has developed an intermediate mechanics course for sophomore-level physics majors that has an explicit focus on physics sensemaking, particularly solution evaluation. The strategies we emphasize include: thinking about mathematical and physical “beasts,” considering special cases, and thinking about the covariational behavior of functions. I will describe how we’ve been thinking about evaluative sensemaking, some of the instructional strategies we’ve used the course, and some of our research about the ways students evaluate algebraic solutions to physics problems. We find that the variety of ways students make sense of algebraic answers to physics problems is dizzying, even when we suggest specific strategies to try. Event Location: Orchard 1001
Event Time: Friday, May 10, 2019 | 9:15 am - 10:45 am
Event Location:
Orchard 1001
Add to Calendar 2019-05-10T09:15:00 2019-05-10T10:45:00 Teaching and learning how to troubleshoot in upper-division labs Event Information: This is a public talk as part of the annual UBC Physics and Astronomy Education Research Group's Open Retreat. Abstract: Troubleshooting systems is an integral part of experimental physics in both research and educational settings. Accordingly, developing students’ ability to troubleshoot is an important goal for undergraduate physics lab courses. My colleagues and I have investigated student approaches to troubleshooting using think-aloud interviews in which pairs of students from two institutions were asked to diagnose and repair a malfunctioning circuit. We have also conducted national-scale studies in which we interviewed over 50 lab instructors about their teaching strategies, with one study focused specifically on efforts to improve students’ troubleshooting abilities. In this presentation, I will draw on findings from these studies and the literature more broadly to paint a picture of teaching and learning how to troubleshoot. I will focus on the roles of model-based reasoning, peer-to-peer metacognitive interactions, and the cognitive apprenticeship style of instruction. Finally, I will discuss practical implications for upper-division lab courses. Electronics lab instructors’ approaches to troubleshooting instruction: https://journals.aps.org/prper/abstract/10.1103/PhysRevPhysEducRes.13.010102 Event Location: Orchard 1001
Event Time: Tuesday, May 7, 2019 | 10:00 am - 12:00 pm
Event Location:
Room 318, Hennings Bldg
Add to Calendar 2019-05-07T10:00:00 2019-05-07T12:00:00 Departmental Oral Examination (Thesis Title: "Aspects of quantum information theory in guantum field theory and gravity") Event Information: Abstract: We discuss applications of quantum information theoretic concepts to quantum gravity and the low-energy regime of quantum field theories. The first part of this thesis is concerned with how quantum information spreads in four-dimensional scattering experiments for theories coupled to quantum electro- dynamics or perturbative quantum gravity. In these cases, every scattering process is accompanied by the emission of an infinite number of soft photons or gravi-tons, which cause infrared divergences in the calculation of scattering probabilities. There are two methods to deal with IR divergences: the inclusive and dressed formalisms. We demonstrate that in the late-time limit, independent of the method, the hard outgoing particles are entangled with soft particles in such a way that the reduced density matrix of the hard particles is essentially completely decohered. Furthermore, we show that the inclusive formalism is ill-suited to describe scattering of wavepackets, requiring the use of the dressed formalism. We construct the Hilbert space for QED in the dressed formalism as a representation of the canonical commutation relations of the photon creation/annihilation algebra, and argue that it splits into superselection sectors which correspond to eigenspaces of the generators of large gauge transformations. In the second part of this thesis, we turn to applications of quantum information theoretic concepts in the AdS/CFT correspondence. In pure AdS, we find an explicit formula for the Ryu-Takayanagi (RT) surface for special subregions in the dual conformal field theory, whose entangling surface lie on a light cone. The explicit form of the RT surface is used to give a holographic proof of Markovicity of the CFT vacuum on a light cone. Relative entropy of a state on such special subregions is dual to a novel measure of energy associated with a timelike vector iiiflow between the causal and entanglement wedge. Positivity and monotonicity of relative entropy imply positivity and monotonicity of this energy, which yields a consistency conditions for solutions to quantum gravity. Event Location: Room 318, Hennings Bldg
Event Time: Monday, May 6, 2019 | 12:40 pm - 3:00 pm
Event Location:
Room 309, Hennings Bldg
Add to Calendar 2019-05-06T12:40:00 2019-05-06T15:00:00 Departmental Oral Examination (Thesis Title: "Investigating the Dark Sector of the Universe Using Cosmological Observables") Event Information: Abstract: Although the Standard Model of particle physics has been a phenomenal success in modelling known particles and predicting new, theoretically founded particles, it is known to be incomplete. Although the Standard Model of cosmology has been a phenomenal success in modelling the evolution of the Universe, it too has open questions that remain unresolved. In this thesis, we aim to address properties of new physics models that are being developed that aim to answer these open questions. In particular, we wish to focus on and examine in detail the connection between the dark sector of the Universe and the visible sector. In examining this connection, we may use cosmological observables to place strict limits on new theories that go beyond the Standard Model. In the first part of this thesis we will address the flow of energy from the visible sector to the hidden via a phenomenon known as freeze-in. Here, we explore the effects that early-time, ultraviolet energy transfer may have on the infrared, late-time evolution of a dark matter candidate. We use a simplified hidden-sector model to highlight the notion that operators that are typically considered early may have relevant late-time effects. Following this, we consider the reverse energy flow, and consider how dark-sector energy injection via decays of electromagnetic radiation may affect the products of Big Bang Nucleosynthesis. In this section, we focus on arbitrary light particle (< 100 MeV) decays, and identify how direct and indirect alteration of the light element abundances can be constrained using the measured values today. Direct alteration is caused by photodissociation, while indirect effects are felt through changes in the radiation energy density. Finally, we consider a full and rich dark sector, consisting of a non-Abelian SU(3) gauge force. This new gauge field presents itself as glueballs after a confining transition. We study the effects of this confining transition, as well as the subsequent dynamic evolution of the spectrum of glueballs produced. In the final chapter, we examine how decays to Standard Model particles via higher-dimensional, non-renormalizable operators can place stringent limits on the parameter space of this gauge force. Event Location: Room 309, Hennings Bldg
Event Time: Friday, April 26, 2019 | 7:00 pm - 8:30 pm
Event Location:
Hennings 202 (6224 Agricultural Road, Vancouver, BC V6T 1Z1)
Add to Calendar 2019-04-26T19:00:00 2019-04-26T20:30:00 Space & Storytelling: How discoveries of new worlds help tell stories of family Event Information: Ria and Elizabeth seem to be authors of a very different type: Ria is a YA (Young Adult) novelist, while Elizabeth is an astrophysicist who writes popular science. The first part of this talk will tackle a crucial question: why are they presenting together? The two authors will discuss how they came to work together unexpectedly through Ria’s novel. Ria will then explain the process and research for her novel, The Centre of the Universe, and how the use of space metaphors help explain relationships between the characters. Elizabeth will then cast a scientific eye over these same metaphors, before moving on to talk in more depth about her own research and book, The Planet Factory. Book signing to follow after the event. This event is presented by UBC Department of Physics & Astronomy and Curiosity Collider Art-Science Foundation. Bios Elizabeth Tasker is an astrophysicist at Japan’s national space agency, JAXA. Her research uses computer models to explore how stars and planets form. She is a keen science communicator, writing principally about planets and space missions for publications that have included Scientific American, Astronomy Magazine and Room, and she is a regular feature writer for the NASA NExSS ‘Many Worlds’ online column. Her popular science book, The Planet Factory, comes out in paperback in Canada this April.   Ria Voros is a YA author whose latest novel, The Centre of the Universe, explores the relationship between mothers and daughters and also explores a teen's passion for astronomy. Ria has an MFA in creative writing from UBC and her books have been nominated for several awards across the country. She writes, teaches and lives in Victoria. Event Location: Hennings 202 (6224 Agricultural Road, Vancouver, BC V6T 1Z1)
Event Time: Friday, April 26, 2019 | 2:00 pm - 5:00 pm
Event Location:
Room 318, Hennings Bldg.
Add to Calendar 2019-04-26T14:00:00 2019-04-26T17:00:00 Departmental Oral Examination (Thesis Title: "Measurement of the Arterial Input Function from Radial MR Projections") Event Information: Abstract: DCE-MRI provides a non-invasive method to probe the health status of tissue and help identify diseases, such as cancer.  Biologically relevant information is extracted by fitting the data to a pharmacokinetic model.  The accuracy of the fit parameters is highly sensitive to the quality of the input curves: the contrast-time curve in the tissue of interest, and the arterial input function, which characterizes the contrast kinetics of a blood vessel feeding the tissue.  The AIF is difficult to measure in pre-clinical studies in mice due to their small body size and limited number of vessels of sufficient size. As a result, several groups use a population averaged AIF from the literature.  This curve does not account for inter or intra individual differences, and is specific to a particular injection protocol. This thesis presents a projection-based measurement that measures the AIF from a single trajectory in k-space, which provides a temporal resolution equal to the repetition time (TR).  The projection-based AIF allows for acquisition of DCE-MRI data between successive measurements, while maintaining a high temporal resolution of both data sets.  A dual-coil experimental platform is set up to acquire a projection-based AIF in the mouse tail, concurrently with DCE-MRI data at a tumour implanted on the hind flank.  The results show that an AIF, with a temporal resolution of 100 ms, may be acquired in the mouse tail.  Using this curve in the model fit provided K_trans = 0.145 min^-1, and v_e = 0.269.  These values are consistent with other studies involving tumours. Event Location: Room 318, Hennings Bldg.
Event Time: Thursday, April 25, 2019 | 1:30 pm - 3:30 pm
Event Location:
Hennings 318
Add to Calendar 2019-04-25T13:30:00 2019-04-25T15:30:00 Departmental Oral Examination (Thesis Title: "Dirac materials and the response to elastic lattice deformation") Event Information: Abstract: Dirac materials have formed a thriving and prosperous direction in modern condensed matter physics. Their bulk bands can linearly attach at discrete points or along curves, leading to arc or drumhead surface states. The candidate Dirac materials are exemplified by Dirac/Weyl semimetals, Dirac/Weyl superconductors, and Dirac/Weyl magnets. Owing to the relativistic band structure, these materials have unique responses to the applied elastic crystalline lattice deformation, which can induce pseudo-magnetic and pseudo-electric fields near the band crossings and produce transport distinguished from that caused by ordinary magnetic and electric fields. In this dissertation, I will demonstrate exotic transport due to the strain-induced gauge field in Weyl semimetals, Weyl superconductors, and Weyl ferromagnets. I will first elucidate that a simple bend deformation can induce a pseudo-magnetic field that can give rise to the Shubnikov-de Haas oscillation in Weyl semimetals. Then I will elaborate that strain can Landau quantize charge neutral Bogoliubov quasiparticles as well and result in thermal conductivity quantum oscillation in Weyl superconductors. Lastly, I will consider the strain-induced gauge field beyond the fermionic paradigm and explain various quantum anomalies of magnons in Weyl ferromagnets. Event Location: Hennings 318
Event Time: Wednesday, April 24, 2019 | 11:00 am - 12:30 pm
Event Location:
Hennings 318
Add to Calendar 2019-04-24T11:00:00 2019-04-24T12:30:00 Spintronics with two-dimensional materials Event Information: Exploitation of the intrinsic spin of an electron, spintronics, could facilitate the development of multifunctional and novel devices. With respect to the material selection, two-dimensional (2D) crystals and their van der Waals heterostructures could enable new spintronics functionalities that are not accessible in bulk materials [1]. Towards building such van der Waals-bonded spin devices, spin transport and magnetic properties of novel 2D materials have been individually studied. In this talk, I will first introduce ultra-thin, semiconducting black phosphorus as a promising material for possible spintronics applications requiring rectification and amplification actions [2]. It exhibits remarkable spin transport properties even at room temperature after an in-situ h-BN encapsulation process. Then, I will demonstrate inducing magnetism into an otherwise non-magnetic 2D material with the creation of some specific types of defects [3]. Because of RKKY exchange couplings across ultra-thin films of this air-stable material, we also observe layer-dependent magnetism.  Finally, I will provide an outlook about the tremendous potential of 2D materials for fundamental spintronics research and the future applications in information storage and logic devices. Event Location: Hennings 318
Event Time: Tuesday, April 16, 2019 | 12:00 pm - 1:00 pm
Event Location:
Room 309
Add to Calendar 2019-04-16T12:00:00 2019-04-16T13:00:00 Magnetotransport in topological metals Event Information: Topological metals continue to attract attention as novel gapless states of matter.  While there by now exists an exhaustive classification of possible topologically nontrivial metallic states,  their observable properties, that follow from the electronic structure topology, are less well understood.  In this talk I will present my recent work on magnetotransport phenomena in topological metals, which may be related to the  chiral anomaly. I will demonstrate that the chiral anomaly leads to strong anisotropic magnetoresistance in such materials,  which manifests in very unusual negative longitudinal magnetoresistance and planar Hall effect. I will also argue that a  smoking-gun feature of the chiral anomaly in topological metals is the existence of propagating chiral density modes even  in the regime of weak magnetic fields. Finally, I will show that the optical conductivity of such metals exhibits an extra peak, which exists on top of the standard metallic Drude peak. The spectral weight of this peak is  transferred from high frequencies and its width is proportional to the chiral charge relaxation rate. Event Location: Room 309
Event Time: Thursday, April 11, 2019 | 9:00 am - 11:00 am
Event Location:
Room 203, Graduate Student Centre (6371 Crescent Road)
Add to Calendar 2019-04-11T09:00:00 2019-04-11T11:00:00 Final PhD Oral Examination (Thesis Title: “Precise Measurement of Rare Pion Decay”) Event Information: Abstract: A precise measurement of the pion to positron or muon decay branching ratio provides a test of lepton universality incorporated in the Standard Model (SM) of particle physics. If a measurement is consistent with the SM, new constraints could be set on new physics. Most remarkably, a deviation could imply the presence of a new pseudo-scalar interaction whose energy scales up to O(1000 TeV) would enhance the branching ratio by O(0.1%). In some instances, these constraints can far exceed the reach of direct searches at colliders. This dissertation represents the latest experimental measurement effort by the PIENU collaboration. The current analysis presented in this thesis is blinded but includes the highest quality data portion available of around 3M  π → e ν events. Furthermore, major experimental systematic problems have been solved, allowing for increased precision up to 0.12% in the branching ratio and up to 0.06% in test of lepton universality. Event Location: Room 203, Graduate Student Centre (6371 Crescent Road)
Event Time: Wednesday, April 10, 2019 | 7:30 pm - 9:00 pm
Event Location:
Centre for Interactive Research on Sustainability (CIRS) - Room 1250 / UBC
Add to Calendar 2019-04-10T19:30:00 2019-04-10T21:00:00 Are We Seeing Hawking Points in the Microwave Sky? Event Information: A dedicated analysis of the cosmic microwave background (CMB), as revealed by both the WMAP and Planck satellites, has discovered numerous previously unobserved highly energetic anomalous 'spots' in the CMB. Such spots are implications of conformal cyclic cosmology (CCC), which proposes that our Big Bang was the (conformal) continuation of a previous cosmic "aeon", wherein these anomalous spots would be the result of the conformally compressed Hawking radiation from supermassive black holes in that previous aeon. It is very hard to see how such anomalous spots can be explained in terms of the conventional inflationary picture of our very early universe. Event Location: Centre for Interactive Research on Sustainability (CIRS) - Room 1250 / UBC
Event Time: Tuesday, April 9, 2019 | 12:00 pm - 2:00 pm
Event Location:
Room 700, Research Pavilion, Vancouver General Hospital (828 West 10th Avenue)
Add to Calendar 2019-04-09T12:00:00 2019-04-09T14:00:00 Departmental Oral Examination (Thesis Title: "Personalized dosimetry protocol for the optimization of Lutetium-177 DOTATATE radionuclide therapy") Event Information: Abstract: Targeted radionuclide therapy has been shown to be one of the most effective treatment options for metastatic neuroendocrine tumours (NETs). In particular, peptide receptor radionuclide therapy (PRRT) with Lutetium-177 (177Lu) labeled DOTATATE results in significantly improved tumour control, while only low to moderate normal tissue toxicity. There is growing evidence that the efficacy of this treatment can be further improved by performing personalized administration of radiopharmaceutical. However, since dosimetry for PRRT is usually considered challenging, traditionally NET patients are treated with same or very similar amounts of 177Lu DOTATATE. The objective of this thesis was to propose a simple, yet accurate dosimetry protocol, which could be easily implemented in clinics for the optimization of 177Lu DOTATATE radionuclide therapy. To achieve this aim, the following physics questions, that are related to image-based dose calculation, were investigated: The performance of camera calibration method using simple planar scans, was compared to that obtained from tomographic acquisitions. To assess the quantitative accuracy of commercial SPECT reconstruction software (Siemens Flash3D), a number of phantom experiments with different photon attenuation conditions were performed. The influence of camera dead-time correction on the estimated dose was investigated. The kidney doses obtained from four time-activity curve creation methods using three data points were compared. In order to simplify the dosimetry, the accuracy of dose estimated based on two data points, or even potentially one data point, was evaluated. Our results show that gamma camera can be accurately calibrated with planar scan of a point-like source. The error of 177Lu activity quantification in large volume (>100mL) was about 5% when proper segmentation was applied to Siemens Flash3D reconstructions. Dead-time correction was found to have no impact on the estimated dose. Kidney dose estimated based on single data measured at 48-72 hours produced small error (<10%) for the majority of patients, thus could be recommended for clinical use. This single data point method can also be applied to other organ, as long as its bio-kinetics can be described by a monoexponential function and the statistical behavior of the population effective half-lives in that organ has been estimated. Event Location: Room 700, Research Pavilion, Vancouver General Hospital (828 West 10th Avenue)
Event Time: Tuesday, April 9, 2019 | 11:00 am - 12:30 pm
Event Location:
Hennings 318
Add to Calendar 2019-04-09T11:00:00 2019-04-09T12:30:00 Tunable correlated phases in ultra-high mobility oxides Event Information: Clean two-dimensional electron systems have been intensively studied due to the astounding array of correlated electronic phases they elicit. In this presentation, I will introduce ZnO-based heterostructures as a new strongly interacting oxide platform for studying the transport of ultra-high mobility carriers. In a magnetic field, we observe a delicate competition between gapped incompressible, compressible and anisotropic nematic phases which may be tuned between by modifying the spin polarization of carriers. In the absence of a magnetic field, dilute samples display a metal-insulator transition as the strength of interactions is increased. Concomitantly, the signatures of a divergent spin susceptibility and spontaneous spin polarization are resolved, suggesting the realization of the elusive Stoner ferromagnet transition in a two-dimensional metal. Event Location: Hennings 318
Event Time: Monday, April 8, 2019 | 3:00 pm - 5:30 pm
Event Location:
Fred Kaiser Building, Room 2020/2030.
2332 Main Mall
Add to Calendar 2019-04-08T15:00:00 2019-04-08T17:30:00 Creating and controlling quantum resources on photonic chips Event Information: As the various quantum photonic platforms mature, we rapidly approach the advent of viable quantum devices.  The different ways in which we can manipulate and create quantum states, and how efficiently we can do so, will determine the types of devices that we can realistically construct.  In this talk, I will cover our recent progress on the control of the properties of epitaxially grown InAs quantum dots embedded in GaAs nanophotonic waveguides, and over their interaction with photons.  I will touch on the high quality of these interactions, and their nonlinear and directional nature, showing that this combination can be used to create a viable photon sorter, and even a bell-state analyzer. I will also cover the manner in which these interactions can be actively and optically controlled by exploiting the inherent nonlinearity of a two-level quantum emitter. In total, these results demonstrate a route towards future quantum technologies, ranging from the creation of single-photon sources to the realization of large-scale quantum networks. Event Location: Fred Kaiser Building, Room 2020/2030. 2332 Main Mall
Event Time: Friday, April 5, 2019 | 11:00 am - 1:00 pm
Event Location:
Room 488, QMI
Add to Calendar 2019-04-05T11:00:00 2019-04-05T13:00:00 Departmental Oral Examination (Thesis Title: "Realizing High-Energy Physics in Topological Semimetals") Event Information: Abstract: The discovery of topological phases of matter has brought high-energy and condensed matter communities together by giving us shared interests and challenges. One fruitful outcome is the broadened range of possibilities to realize high-energy physics in table-top experiments. My collaborators and I have found scenarios in which influential high-energy ideas emerge in solid-state systems built from topological semimetals – gapless topological phases which have drawn intense research efforts in recent years. This Thesis details our proposals for realizing Majorana fermions, Adler-Bell-Jackiw anomaly, and holographic black holes in superconductor-Weyl-semimetal heterostructures, mechanically strained Weyl semimetal nanowires/films, and graphene flakes subject to strong magnetic fields, respectively. By analyzing the effects of realistic experimental conditions, we will demonstrate that our proposals are experimentally tangible with existing technologies. Event Location: Room 488, QMI
Event Time: Thursday, April 4, 2019 | 4:00 pm - 5:00 pm
Event Location:
Hennings 201
Add to Calendar 2019-04-04T16:00:00 2019-04-04T17:00:00 Searching for Axion Dark Matter: Quantum Sensors and the Dark Matter Radio Event Information: One of the most enduring mysteries in particle physics is the nature of the non-baryonic dark matter that makes up 85% of the matter in the universe. For several decades, most searches for this mysterious substance have focused on Weakly Interacting Massive Particles (WIMPs). Recently, there has been a surge in theoretical interest in ultra-light, wave-like dark matter candidates, including the strongly motivated QCD axion. I will describe a suite of experiments (including both NMR and electromagnetic coupling) that will be used to probe the QCD axion over more than six orders of magnitude of mass (~100 Hz to ~300 MHz), and the development of quantum sensors to enhance these searches. I will focus in particular on the Dark Matter Radio (DM Radio), an experiment searching for axions by their coupling to a lumped-element electromagnetic resonators. Quantum measurement techniques can be used to evade the standard quantum limit by the  exploitation of quantum correlations in the electromagnetic signals in a resonator. In fact, the use of quantum sensors is required to be able to fully probe the QCD axion over the mass range below 300 MHz. I will describe the RF Photon Upconverter (RPU), which can be used to implement techniques including backaction evasion to outperform the Standard Quantum Limit at the RF frequencies probed by DM Radio. Event Location: Hennings 201
Event Time: Thursday, April 4, 2019 | 2:00 pm - 3:30 pm
Event Location:
BRIM 311
Add to Calendar 2019-04-04T14:00:00 2019-04-04T15:30:00 CM Seminar: Quantum materials: insights from near field nano-optics Event Information: In 1944 Hans Bethe reported on “the diffraction of electromagnetic radiation by a hole small compared with the wave-length” [Physical Review 66, 163 (1944)]. This seminal paper was among the early precursors to a new and vibrant area of research: near field nano-optics. I will discuss recent nano-optical experiments on quantum materials including graphene and other atomically layered crystals. Central to the nano-optical exploration of quantum materials is the notion of polaritons: hybrid light-matter modes that are omnipresent in polarizable media [Nature Materials 16, 1077 (2017)]. Infrared nano-optics allows one to directly image polaritonic standing waves yielding rich insights into the electronic phenomena of the host material supporting polaritons [Science 354, 195 (2016)]. We utilized this novel general approach to investigate the physics of ballistic electronic transport in graphene [Nature 557, 530 (2018)] and of topological conducting channels also  in graphene [Science 362, 1153 (2018)].   Event Location: BRIM 311