Sheperd Doeleman
Harvard-Smithsonian Center for Astrophysics

In April 2017, the Event Horizon Telescope (EHT) carried out a global Very Long Baseline Interferometry (VLBI) observing campaign at a wavelength of 1mm that led to the first resolved image of a supermassive black hole. For the 6.5 billion solar mass black hole in the giant elliptical galaxy M87, the EHT estimated the spin orientation and constrained models of accretion on Schwarzschild radius scales. This work relied on two decades of technical advances in ultra-high resolution interferometry and theoretical General Relativistic Magnetohydrodynamic (GRMHD) simulations. This talk will review these advances and recent new EHT results. We will also look to the next decade when a next-generation EHT (ngEHT) that doubles the number of participating radio dishes in the VLBI network will enable time-lapse movies of M87 that link the black hole to the relativistic jet it powers.  SgrA*, the 4 million solar mass black hole at the Galactic Center, evolves 1000 times more rapidly than M87, and for this source the ngEHT will produce real-time video.

Oussama Moutanabbir
Department of Engineering Physics, École Polytechnique de Montréal, Montréal, Canada

Abstract

This presentation will describe the basic properties of (Si)GeSn semiconductors and outline strategies to exploit them to extend the capabilities of silicon-compatible devices and discuss physics and engineering concepts to achieve silicon-integrated mid-infrared optoelectronics and quantum technologies. (Si)GeSn alloys constitute isovalent substitution of group-IV elements in cubic diamond-structured (Si)Ge lattices. This emerging family of semiconductors provides strain and composition as two degrees of freedom to independently engineer the lattice parameter and the band structure, in a similar fashion to the mature compound semiconductors. We will show that these new capabilities can be introduced to engineer scalable and monolithic SWIR and MWIR photodetectors and light-emitters. We will also demonstrate new platforms based on (Si)GeSn low-dimensional systems to achieve a selective confinement of light-holes, thus laying the groundwork toward coherent photon-spin interfaces needed for a direct mapping of the quantum information encoded in photon flying qubits to stationary spin processor.  

Bio

Oussama Moutanabbir is Professor of Engineering Physics holding a Canada Research Chair in Nanoscale and Quantum Semiconductors. Before taking the position in Montreal, he was Project Leader at the Max Planck Institute of Microstructure Physics (Germany) and held a joint appointment as Invited Researcher at RIKEN Institute of Advanced Science (Japan). He is the Director of POLYAPT – a newly established multi-institutional center for atom probe tomography. He is currently leading a national network on compact mid-infrared and terahertz photonics funded by Defence Canada through its program Innovation for Defence Excellence and Security. His collaborative work with Université de Sherbrooke and Teledyne-Dalsa, leading to the development and commercialization of uncooled thermal cameras, received the 2015 ADRIQ’s Innovation Award, the 2015 ADRIQ’s University-Industry Partnership Award, and the 2019 NSERC’s Synergy Award. He is also the recipient of the 2022 Leibniz IKZ International Award for his contributions to the field of group IV semiconductors.

J.E. Sipe
Department of Physics, University of Toronto

Abstract

The response of solids to incident electromagnetic fields is often heuristically described in terms of macroscopic polarization and magnetization fields. In condensed matter physics, the “modern theory of polarization,” and its extension to magnetization, gives this a new level of rigour for time independent and uniform applied fields. We review the philosophy and main results of that strategy, and report on a new approach based on introducing microscopic polarization and magnetization fields. This “post-modern” approach can be used to address the response of crystals to electromagnetic fields varying arbitrarily in space and time, and connects that response to aspects of the underlying topology of the band structure. We compare it to earlier work on atoms and molecules, identifying important similarities and differences.

A. W. Peet
University of Toronto

Abstract

A grand goal in modern theoretical physics is to figure out the operating system of the universe - for subatomic particles and their interactions, and for the fabric of spacetime itself. Quantum Mechanics is great for describing small things, and General Relativity is great for describing heavy things, but deep puzzles remain about how to combine them together. I will give an accessible introduction to recent advances in understanding black hole physics using ideas from string theory and holography toolkits. I will also offer experience-based reflections on how to make physics more welcoming to people from rainbow communities and to people managing physical/mental health conditions. No previous experience with any of these topics will be expected, and all are welcome.

Kate Scholberg
Duke University

Abstract

When a massive star collapses at the end of its life, nearly all of the gravitational binding energy of the resulting compact remnant is released in the form of a brilliant burst of neutrinos. I will discuss the nature of the core-collapse neutrino burst and what we can learn about particle physics and about astrophysics from the detection of these neutrinos. I will cover supernova neutrino detection techniques in general, current supernova neutrino detectors, and prospects for specific future experiments.

Prof. Leonardo Midolo
Copenhagen

Abstract

Photons are essential for securely transmitting information over long distances and realizing quantum entanglement on a global scale. Recent advances in photonic quantum technologies provide the fundamental tools for generating and manipulating photons within a chip. Yet, performing large-scale experiments, involving many quantum bits (or qubits), remains a major challenge.

In this talk, I will introduce the field of integrated quantum photonics and present the current advances in building a new class of integrated devices based on mechanical motion at the nanoscale, known as nano-opto-electromechanical systems (NOEMS). Unparalleled by other methods, NOEMS enable full control over light propagation in optical circuits with low loss, which makes them fully compatible with single-photon emitters. With such an efficient strategy to control light, a fully integrated platform for quantum information processing with several qubits and logical gates, can be built.