Underground quantum computing research targets cosmic radiation disruption
Credit: Snolab, SNOLAB, located underground in Canada, boasts the lowest muon flux globally, with advanced testing facilities perfect for quantum technology research.
Researchers at Chalmers University of Technology in Sweden and the University of Waterloo in Canada are undertaking a novel approach to address the challenge of cosmic radiation in quantum computing.
They are conducting experiments deep underground to mitigate the disruptions caused by cosmic rays on quantum computers. The primary issue stems from these rays affecting the qubits—central to quantum calculations—making them lose their quantum state and cease computations.
The study compares the behaviour of superconducting qubits in above-ground facilities in Sweden and Canada, followed by tests in a unique underground setting.
These underground experiments are conducted in the Vales Creighton mine near Sudbury, Ontario, within the world's deepest clean room, two kilometres below the surface. The substantial depth provides a natural barrier against cosmic rays, potentially offering a more stable environment for quantum computing.
Per Delsing, Professor of Quantum Technology at Chalmers University of Technology and Director of the Wallenberg Center for Quantum Technology, explains the significance of this undertaking:
“We are super excited about this project because it addresses the very important question of how cosmic radiation affects qubits and quantum processors. Gaining access to this underground facility is crucial to understanding how the effects of cosmic radiation can be mitigated.”
The research is conducted in collaboration with SNOLAB, a Canadian research facility known for having the world’s lowest muon flux )particles formed when cosmic rays reach the Earth's atmosphere), which is beneficial for studies requiring minimal cosmic interference.
Jeter Hall, Director of research at SNOLAB and Adjunct Professor at Laurentian University in Canada, highlights the facility's capabilities:
“SNOLAB maintains the lowest muon flux* in the world and has advanced cryogenics testing capabilities, making it an ideal place to conduct valuable research on quantum technologies.”
One critical hurdle for the widespread implementation of quantum computing is the development of effective error correction methods. Current error correction models for quantum systems assume that each error occurs independently, an assumption that does not hold for correlated errors affecting multiple qubits simultaneously. The study aims to deepen the understanding of how these correlated errors can be managed more effectively.
The research project is funded by the grant "Advanced Characterisation and Mitigation of Qubit Decoherence in a Deep Underground Environment," provided by the Army Research Office of the U.S. Combat Capabilities Development Command's Army Research Laboratory.
It is part of a larger initiative by the Wallenberg Centre for Quantum Technology, supported primarily by the Knut and Alice Wallenberg Foundation, which seeks to advance Sweden as a leader in the quantum technology field.
Dr. Chris Wilson, Professor at the University of Waterloo and affiliated with the Institute for Quantum Computing, states:
“With this project, we hope to start understanding what’s going on with the qubit decoherence in relation to cosmic rays, and then start understanding how the radiation affects the qubits in more controlled ways.”
