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News

Four University of Waterloo researchers, including Dr. Michael Reimer, a faculty member at the Institute for Quantum Computing and a professor in the Department of Electrical and Computer Engineering, were awarded funding earlier this month from the Ontario government for innovative research that ranges from cleaning up arsenic-laden mine waste, treating potential virus outbreaks, and using artificial intelligence to protect valuable financial data.

En francais

University of Waterloo researchers combine Nobel prize winning concepts to achieve scientific breakthrough.

Researchers at the University of Waterloo’s Institute for Quantum Computing (IQC) have brought together two Nobel prize winning research concepts to advance the field of quantum communication.

En francais

The National Killam Program administered by the National Research Council of Canada (NRC) announces Dr. Adam Wei Tsen as the recipient of the 2024 Dorothy Killam Fellowship. This prestigious honour provides $80,000 for up to two years in support for dedicated research time to scholars “whose superior, ground-breaking, best-in-class research stands to have significant impact on a national or global scale.” 

Tsen is a professor at the Institute for Quantum Computing (IQC) and the Department of Chemistry at the University of Waterloo. His research focuses on the study of various two-dimensional (2D) quantum materials and making new magnetically active molecules for quantum material applications, including quantum computing and quantum information.

Events

IQC Seminar - Ashutosh Marwah, University of Montreal

Quantum-Nano Centre, 200 University Ave West, Room QNC 1201
Waterloo, ON CA N2L 3G1

For a state $\rho_{A_1^n B}$, we call a sequence of states $(\sigma_{A_1^k B}^{(k)})_{k=1}^n$ an approximation chain if for every $1 \leq k \leq n$, $\rho_{A_1^k B} \approx_\epsilon \sigma_{A_1^k B}^{(k)}$. In general, it is not possible to lower bound the smooth min-entropy of such a $\rho_{A_1^n B}$, in terms of the entropies of $\sigma_{A_1^k B}^{(k)}$ without incurring very large penalty factors. In this paper, we study such approximation chains under additional assumptions. We begin by proving a simple entropic triangle inequality, which allows us to bound the smooth min-entropy of a state in terms of the R\'enyi entropy of an arbitrary auxiliary state while taking into account the smooth max-relative entropy between the two. Using this triangle inequality, we create lower bounds for the smooth min-entropy of a state in terms of the entropies of its approximation chain in various scenarios. In particular, utilising this approach, we prove approximate versions of the asymptotic equipartition property and entropy accumulation. In a companion paper, we show that the techniques developed in this paper can be used to prove the security of quantum key distribution in the presence of source correlations.

IQC Colloquium/IEEE-SSCS Distinguished Lecture - René-Jean Essiambre, Nokia/Bell Labs

University of Waterloo, 200 University Ave W. Waterloo, QNC 0101

The first part of this presentation will provide a brief overview of optical technologies that enabled high-capacity fiber-optic communication systems, from single-mode fibers to fibers supporting multiple spatial modes. A perspective on the evolution of high-capacity systems will be discussed. The second part of the talk will focus on power-e ciency optical detection systems. More specifically, we will describe an experimental demonstration of a system operating at 12.5 bits/photon with optical clock transmission and recovery on free-running transmitters and receivers.

About René-Jean Essiambre Dr. Essiambre worked in the areas of fiber lasers, nonlinear fiber optics, advanced modulation formats, space-division multiplexing, information theory, and high-photon-e ciency systems. He participated in the design of commercial fiber-optic communication systems where several of his inventions were implemented. He has given over 150 invited talks and helped prepare and delivered the 2018 Physics Nobel Prize Lecture on behalf of Arthur Ashkin. He served on or chaired many conference committees, including OFC, ECOC, CLEO, and IPC. He received the 2005 Engineering Excellence Award from OPTICA and is a fellow of the IEEE, OPTICA, IAS-TUM, and Bell Labs. He was President of the IEEE Photonics Society (2022-2023) and is currently the Past-President (2024-2025).

Tuesday, April 2, 2024 2:30 pm - 3:30 pm EDT (GMT -04:00)

Quantum Computational Advantages in Energy Minimization

IQC Special Colloquium Leo Zhou, California Institute of Technology

Quantum-Nano Centre, 200 University Ave West, Room QNC 1201 Waterloo, ON CA N2L 3G1

Finding the minimum of the energy of a many-body system is a fundamental problem in many fields. Although we hope a quantum computer can help us solve this problem faster than classical computers, we have a very limited understanding of where a quantum advantage may be found. In this talk, I will present some recent theoretical advances that shed light on quantum advantages in this domain. First, I describe rigorous analyses of the Quantum Approximate Optimization Algorithm applied to minimizing energies of classical spin glasses. For certain families of spin glasses, we find the QAOA has a quantum advantage over the best known classical algorithms. Second, we study the problem of finding a local minimum of the energy of quantum systems. While local minima are much easier to find than ground states, we show that finding a local minimum under thermal perturbations is computationally hard for classical computers, but easy for quantum computers. These results highlight exciting new directions in leveraging physics-inspired algorithms to achieve quantum advantages in broadly useful problems.