Building better quantum networks

New project harnesses expertise from across Canada to explore how quantum computers establish connections and send information over long distances.

Lindsay LeBlanc

Physicist Lindsay LeBlanc is leading a new national collaboration exploring both fundamental research and practical applications of next-generation quantum computing networks. (Photo: John Ulan; lasers in LeBlanc’s lab are turned off per safety protocols)

Though quantum physics looks at things that are very small — think atoms and electrons — it holds the potential to address big questions and problems. And as the scope of quantum technology research grows, it’s getting bigger than one person, one lab or even one university can tackle, according to a University of Alberta researcher leading a new national collaboration aimed at bringing next-generation quantum computer networks from the lab into real life.

“We’re starting to get into the realm of needing to work together because we can’t be experts in all the different pieces,” says Lindsay LeBlanc, associate professor in the Department of Physics and Canada Research Chair in Ultracold Gases for Quantum Simulation.

LeBlanc is leading a project titled ARAQNE (Alliance for Research and Applications of Quantum Network Entanglement), which received $5 million in funding over five years through an NSERC Alliance Consortia Quantum grant announced this week.

“The goal of what we’re doing is to develop quantum networking technologies — both fundamental research and some very practical applications of it,” says LeBlanc.

ARAQNE’s name was inspired by the Greek mythological figure Arachne, a weaver who was transformed into a web-spinning spider. The name couldn’t be more appropriate — the researchers behind ARAQNE are looking to answer questions about how information nodes can connect and be woven together over long distances, and how to effectively send information and link quantum computers.

Quantum computers need to be able to perform huge, complex calculations to solve problems like streamlining the process of developing new chemicals and drugs. “The larger-scale quantum computations you can do, the more interesting and useful calculations are possible,” says LeBlanc.

However, even as technological advances allow researchers to create quantum processors that can handle more and more qubits (where quantum information is stored, akin to the binary digit or “bit” in regular computing), these devices have a limit. The solution is to find out how to get multiple computers to process computations together, something called distributed quantum computing. 

“It’s always going to be hard to make large-scale processors where you have many qubits working together to do the calculations,” says LeBlanc. “No matter how big we make the processors, we’re always going to want more. So understanding how to efficiently link these processors together is an important milestone in quantum computing.”

LeBlanc’s lab also focuses on quantum memory, which is an essential part of the communications component of the ARAQNE project. Quantum memory serves the same purpose as a hard drive does in a regular computer, except rather than storing information in binary, on-or-off states, it stores information in a quantum state. To successfully interact, these pieces of quantum information often have to combine at particular times and in particular ways.

“Our lab is working on developing quantum memories that are not just good in the lab, but can actually be deployed in the field and have long enough hold times to be practical,” says LeBlanc.

Quantum communication also allows more secure networks. As LeBlanc explains, the idea is “not that you can’t hack it, but that you always know if it is hacked.”

Currently, the main consumers of this type of technology are financial institutions, military and government, due to the high cost and need for ironclad security involved. But as researchers discover better ways to link quantum processors and efficiently transmit information through them, these high-security systems may become more widely accessible.

“Eventually, you might have a quantum link to your home. You could actually have a secure link to your bank or your health information,” says LeBlanc. “It’s the ability to have that unconditional security.”

“The hope is to deploy real equipment and actually test some of these things in the city or over even longer distances,” she adds. 

This is where industry partners factor in. One of ARAQNE’s partners is TELUS, which is helping the researchers bring the science from the lab to the real world of telecommunications. 

“They’re interested in quantum communications, and part of their contribution is to actually give us time on real fibre to try these things out in real circumstances.”

Other partners include the City of Calgary and two small startups in the quantum space. LeBlanc’s research collaborators on the grant are physics professor John Davis along with researchers from the University of Calgary, University of Ottawa, Simon Fraser University, University of Toronto and University of Waterloo.

The federal government has invested more than $1 billion in quantum research and science since 2009, and in Budget 2021, committed $360 million to support the National Quantum Strategy

Collaborations like ARAQNE involving multiple universities are critical to build on Canada’s strengths in quantum research and advance the field beyond what institutions could achieve on their own, says LeBlanc.

“These bigger pieces of funding are for bringing people together to do bigger things.”

LeBlanc was awarded an additional $25,000 from NSERC for her project entitled, “Integrating organic-molecule single-photon sources with atomic quantum memories,” and Karthik Shankar, professor in the Department of Electrical & Computer Engineering, received $25,000 for a project entitled, “Engineering quantum sensors exploiting rabi splitting in plexcitonic nanoparticle assemblies.”