George Watkins and Alex Nguyen, both undergraduate students from the SFU School of Computing Science, have recently received a grant award from the Unitary Fund to develop a compiler for error-correcting quantum computing. 

Quantum computers are next-generation computing devices that are expected to dramatically outperform current `classical’ computers in a variety of important tasks, such as optimization, machine learning and molecular simulation. Computing power is enhanced by harnessing the properties of quantum mechanics, the physical law governing subatomic particles, but not usually observed in daily-life objects, including all of today’s computers. However, information encoded in quantum devices is fundamentally forbidden to be cloned and is fragile against even the tiniest environmental influence. Therefore, there is a pressing need to develop error correction procedures dedicated for quantum computers that are radically different from their counterparts in current computers. 

The work by Watkins and Nguyen, who are co-supervised by SFU computing science lecturer Steven Pearce and physics professor Kero Lau, is to develop an open source, end-to-end compiler that converts any unprotected quantum computing circuit to an error-corrected version. They use a technique called lattice surgery, which spreads out the encoded information into grids of quantum bits, and processes the data by joining and separating the grids. 

“We aim to build a compiler that anyone, even without any prior knowledge about quantum error correction, can get the instructions on how to rearrange their quantum program to enjoy the protection given by lattice surgery,” says Watkins. 

To cater to beginners, advanced users and researchers, the compiler is accessible through a public web interface and developed as an open source package. A prototype is available on https://latticesurgery.com.

This research began as a class project during the School of Computing Science’s new course on Quantum Algorithms (CMPT 409) in Summer 2020. It continued as an Honour’s Thesis project in the 2020-2021 academic year and eventually expanded into an international collaboration co-supervised by UBC physics professor Robert Raussendorf, quantum computer scientists Alexandru Paler (Aalto) and Varun Seshadri (TU Munich), and SFU alumnus Keelan Watkins. The team recently received funding from the Unitary Fund for the next phase of development. 

“In the coming months we will expand the functionality of our compiler to include correctness verification, benchmarking and error model simulation,” says Nguyen. 

The team also plans to demonstrate their product in international conferences, such as the quantum compiler session in the APS March Meeting. 

The potential of quantum technologies has encouraged the federal government to launch a National Quantum Strategy to foster quantum-related research and commercialization in Canada. SFU is developing new research programs in this area and new quantum computing-related courses are being added to the undergraduate programs of various departments. Workshops and seminars are being offered in collaboration with the partners at Quantum BC and beyond. 

“We wish to provide more training and research opportunities to our students, so that they can explore the possibilities in this `quantum blue sea’,” says Pearce.