Quantum computing has unlimited potential in promoting material discovery, artificial intelligence, biochemical engineering and many other disciplines. However, because the basic building block of quantum computer-qubits itself is very fragile, a long-term obstacle of quantum computing is to effectively realize quantum error correction.
Researchers at the University of Massachusetts Amherst have found a way to protect quantum information from common error sources in superconducting systems. Superconducting system is one of the main platforms to realize large-scale quantum computers. This research, published in the journal Nature, has realized a new method of automatically correcting quantum errors.
ARO is part of the US Army Combat Capability Development Command. As a part of the Air Force Research Laboratory, AFOSR supports the basic research of the Air Force and the Space Force.
"This is a very exciting achievement, not only because the team can demonstrate the basic concept of error correction, but also because the results show that the whole method is realized in a resource-efficient way." Sara Gamble, project manager of ARO Quantum Information Science, said, "As the scale of quantum computing system expands to the scale required by military-related applications, efficiency becomes more and more important."
Today's computers are composed of transistors representing classical bits, either 1 or 0. Quantum computing is a new paradigm of computing by using quantum bits or qubits. Exponential processing power can be obtained through quantum superposition and entanglement.
The existing quantum error correction demonstrations are active, which means that they need to check the errors regularly and fix them immediately. This requires hardware resources and hinders the expansion of quantum computers.
On the contrary, the researchers' experiments realize passive quantum error correction by adjusting the friction or dissipation experienced by qubits. Because friction is usually regarded as the bane of quantum coherence, this result seems surprising. The trick is that dissipation must be designed in a quantum way.
This general strategy has a history of 20 years in theory, but how to obtain this dissipation and apply it to quantum error correction has always been a challenge.
Dr Grace Metcalfe, a quantum information science project officer at AFOSR, said: "Showing these unconventional methods is expected to inspire smarter ideas to overcome some of the most challenging problems in quantum science."
Looking ahead, researchers say that this means that there may be more ways to protect qubits from errors, and the cost is lower.
"Although our experiment is still a fairly elementary argument, we finally realized this counterintuitive theoretical possibility of dissipative QEC." Dr Wang Chen, a physicist at the University of Massachusetts at amherst, said. "In the medium and long term, this experiment provides the possibility for building a practical fault-tolerant quantum computer."
Translation /Foresight Economist APP information section
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