Events

Magdalena Stobinska, University of Warsaw

It is an open question how fast information processing can be performed and whether quantum effects can speed up the best existing solutions. Signal extraction, analysis, and compression in diagnostics, astronomy, chemistry, and broadcasting build on the discrete Fourier transform. It is implemented with the fast Fourier transform (FFT) algorithm that assumes a periodic input of specific lengths, which rarely holds true. A lesser-known transform, the Kravchuk-Fourier (KT), allows one to operate on finite strings of arbitrary length.

Special Seminar featuring Wenchao Xu, MIT

Photons interact weakly in vacuum. Finding an optical medium that manifests optical nonlinearity at individual photon level is fascinating, as it opens the possibility to build up all-optical quantum devices, and form novel quantum many-body states of lights.

Nicole Yunger Halpern, Harvard University

Thermodynamics has shed light on engines, efficiency, and time’s arrow since the Industrial Revolution. But the steam engines that powered the Industrial Revolution were large and classical. Much of today’s technology and experiments are small-scale, quantum, far from equilibrium, and processing information.

Due to the APS March Meeting being canceled, IQC has scheduled a mini-symposium for University of Waterloo students to give their accepted talks.

Talks are open for all to attend.

Dr. John Donohue is a quantum physicist and science communicator, currently acting as the Scientific Outreach Manager at the Institute for Quantum Computing and University of Waterloo. He holds a PhD in Physics and Quantum Information, and has conducted research in quantum optics in Canada and Germany. At IQC, John works to break down quantum mechanics to its essence, through classes, workshops, activities, and exhibits. John is interested in how to “count” light by measuring photons, the individual and indivisible particles that make it up.

Colloquium featuring Matthias Christandl, University of Copenhagen - to be held on WebEx

Entanglements are the strong correlations that arise in quantum mechanics. Today we think of them as resources that are being consumed in quantum computation and communication. The teleportation of one qubit from Alice to Bob, for instance, requires one pair of entangled qubits. Measuring the amount of entanglement is thus an essential skill, not least for benchmarking current experiments.

Colloquium featuring Avishay Tal, University of California, Berkeley

The query model offers a concrete setting where quantum algorithms are provably superior to randomized algorithms. Beautiful results by Bernstein-Vazirani, Simon, Aaronson, and others presented partial Boolean functions that can be computed by quantum algorithms making much fewer queries compared to their randomized analogs. To date, separations of $O(1)$ vs.

Seminar featuring Hui Wang, Dartmouth College

In the Unruh Effect (UE) a uniformly accelerating observer (photodetector) is expected to ’see' thermal photons in vacuum while an inertial observer would see none. A longstanding challenge to demonstrate the UE in the lab is that a photodetector's required proper acceleration seems impossibly high for any current or planned table top experiment. In this presentation, we describe two complementary ways to realize close analogues of the UE that overcome the apparent need for large proper accelerations.

Arjan Cornelissen - QuSoft - University of Amsterdam, June 22, 2020 at 2:30 p.m. Zoom webinar

The span program formalism is an important tool in the design of quantum algorithms. It is known that there is a constructive correspondence between span programs and quantum algorithms with optimal query complexity, making this framework especially suitable for designing query-efficient algortihms. However, much less is known about the time complexity of the algorithms produced by this formalism.

Colloquium featuring Carl Alexander Miller - QuICS and NIST

How can two parties carry out a fair coin flip across a noiseless quantum channel? In 2007, Carlos Mochon proved a tantalizing result: he showed that fair quantum coin flipping is possible in principle, but he used a protocol that required a huge (exponential) number of communication rounds. In the twelve years since, despite some continued deep theoretical work on the problem, no improvements to the efficiency of Mochon's protocol have been made.