Researchers at Google and the University of California, Santa Barbara (UCSB) have developed what they say is a reliable approach for addressing one of the many challenges involved in building quantum computers.
The breakthrough involves a method for detecting and preventing certain types of computational errors that occur when quantum memory elements are disturbed in their environment, according to Google.
One of the primary challenges with quantum computing is that the memory elements are prone to errors, the researchers said in a blog post Wednesday. “They’re fragile and easily disturbed—any fluctuation or noise from their environment can introduce memory errors, rendering the computations useless.”
The research by Google and UCSB offers a way around this problem, according to the blog post.
Quantum computers promise many magnitude times faster computational speeds than conventional digital systems because, among other things, they use quantum bits, or qubits, rather than electrical transistors to represent data.
Unlike transistors, each of which is always either a 1 or a 0, a qubit is a memory unit that can represent both a 1 and a 0 at the same time. This allows quantum computers to take what MIT Technology Review describes as “shortcuts through complex calculations.”
The problem though is that getting even just a small number of qubits to work together to perform quantum logic operations repeatedly and still be nearly error-free is extremely difficult, according to the Google researchers.
“But our team has been developing the quantum logic operations and qubit architectures to do just that,” they said.
The Quantum Error Correction (QEC) method developed by Google and UCSB involves programming groups of nine qubits together in such a way so each qubit is able to detect and protect other qubits from errors. “This [QEC] can overcome memory errors by applying a carefully choreographed series of logic operations on the qubits to detect where errors have occurred,” the researchers said.
Details of the research, titled “State preservation by repetitive error detection in a superconducting quantum circuit,” were published in the journal Nature.
Google first revealed its interest in the quantum computing space last September when it disclosed plans to work with UCSB to design and build what it described as new quantum information processors based on superconducting electronics.
Google’s Quantum Artificial Intelligence team is headed by John Martinis, a former professor at UCSB who joined Google last year.
A that time, Google described Martinis as among the leaders in the quantum electronic space noted for his pioneering work around quantum control and quantum information processing.
The Quantum AI team’s mission is to implement and test new designs based on theoretical work as well as Google’s own research in the area. In addition to UCSB, Google’s researchers are working with scientists from D-Wave, a leader in the commercial quantum computing space, whose systems are currently in use at several organizations including Lockheed Martin and NASA.
The Google AI team is also collaborating with scientists at NASA’s Quantum Artificial Intelligence Laboratory to develop and test new approaches to building quantum computers.
Microsoft is another major technology vendor that is currently engaged in exploring both theoretical and experimental approaches to quantum computing, The company has built a team of researchers, theorists and experimentalists in such areas as mathematics, physics and computer science to advance understanding of quantum computing and its applications.
