Welcome to the Institute for Quantum Computing

News

The Government of Canada has invested nearly $7M into quantum projects at the University of Waterloo through recently announced NSERC Alliance Grants. The grants, awarded by the Natural Sciences and Engineering Research Council of Canada (NSERC), encourage university researchers to collaborate with partner organizations from across the private, public or not-for-profit sectors.

Thursday, March 14, 2024

Quantum Community

En francais

With a focus on collaboration and community, the Institute for Quantum Computing (IQC) is proud to host regular social events for our members. While media and popular culture often portray the image of a lone researcher working late nights in a lab or at a computer to make breakthroughs, the more realistic portrayal of new ideas and discoveries can be encompassed through partnerships and teamwork.

En francais

Since 2017, the Quantum Quest Seed Fund (QQSF) has awarded more than $2.88 million to quantum researchers across the University of Waterloo. This winter’s round of funding has been awarded to three Waterloo professors, as they explore and innovate new ideas and applications for quantum devices.

Events

Tuesday, March 19, 2024 9:00 am - 10:00 am EDT (GMT -04:00)

On quantum time complexity of divide and conquer

Math CS Seminar - Jinge Bao, National University of Singapore

200 University Ave W. Waterloo - ZOOM

We initiate a systematic study of the time complexity of quantum divide and conquer algorithms for classical problems. We establish generic conditions under which search and minimization problems with classical divide and conquer algorithms are amenable to quantum speedup and apply these theorems to an array of problems involving strings, integers, and geometric objects. They include LONGEST DISTINCT SUBSTRING, KLEE'S COVERAGE, several optimization problems on stock transactions, and k-INCREASING SUBSEQUENCE. For most of these results, our quantum time upper bound matches the quantum query lower bound for the problem, up to polylogarithmic factors.

https://arxiv.org/abs/2311.16401

Wednesday, March 20, 2024 12:00 pm - 1:00 pm EDT (GMT -04:00)

IQC Student Seminar Featuring Sarah Li

Improving the Fidelity of CNOT Circuits on NISQ Hardware

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

We introduce an improved CNOT synthesis algorithm that considers nearest-neighbour interactions and CNOT gate error rates in noisy intermediate-scale quantum (NISQ) hardware. Our contribution is twofold. First, we define a \Cost function by approximating the average gate fidelity Favg. According to the simulation results, \Cost fits the error probability of a noisy CNOT circuit, Prob = 1 - Favg, much tighter than the commonly used cost functions. On IBM's fake Nairobi backend, it fits Prob with an error at most 10^(-3). On other backends, it fits Prob with an error at most 10^(-1). \Cost accounts for the machine calibration data, and thus accurately quantifies the dynamic error characteristics of a NISQ-executable CNOT circuit. Moreover, it circumvents the computation complexity of calculating Favg and shows remarkable scalability. 


Second, we propose an architecture-aware CNOT synthesis algorithm, NAPermRowCol, by adapting the leading Steiner-tree-based synthesis algorithms. A weighted edge is used to encode a CNOT gate error rate and \Cost-instructed heuristics are applied to each reduction step. Compared to IBM's Qiskit compiler, it reduces \Cost by a factor of 2 on average (and up to a factor of 8.8). It lowers the synthesized CNOT count by a factor of 13 on average (up to a factor of 162). Compared with algorithms that are noise-agnostic, it is effective and scalable to improve the fidelity of CNOT circuits. Depending on the benchmark circuit and the IBM backend selected, it lowers the synthesized CNOT count up to 56.95% compared to ROWCOL and up to 21.62% compared to PermRowCol. It reduces the synthesis \Cost up to 25.71% compared to ROWCOL and up to 9.12% compared to PermRowCol. NAPermRowCol improves the fidelity and execution time of a synthesized CNOT circuit across varied NISQ hardware. It does not use ancillary qubits and is not restricted to certain initial qubit maps. It could be generalized to route a more complicated quantum circuit, and eventually boost the overall efficiency and accuracy of quantum computing on NISQ devices. 

Joint-work with: Dohun Kim, Minyoung Kim, and Michele Mosca

Monday, March 25, 2024 2:30 pm - 3:30 pm EDT (GMT -04:00)

Fundamental physics at the quantum limits of measurement

IQC Colloquium - Daniel Carney, Berkeley Labs

200 University Ave. W. Waterloo Ontario, QNC 0101

The search for new fundamental physics -- particles, fields, new objects in the sky, etc -- requires a relentless supply of more and more sensitive detection modalities. Experiments looking for new physics are starting to regularly encounter noise sources generated by the quantum mechanics of measurement itself. This noise now needs to be engineered away. The search for gravitational waves with LIGO, and their recent use of squeezed light, provides perhaps the most famous example. More broadly, searches for various dark matter candidates, precision nuclear physics, and even tests of the quantization of gravity are all now working within this quantum-limited regime of measurement. In this talk, I will give an overview of this set of ideas, focusing on activity going on now and what can plausibly be achieved within the next decade or so.