Researchers in the UK and the US have published a paper detailing discoveries that could bring a fully functional quantum computer closer to reality.
Quantum computing, which has been researched for decades, has faced the problem of keeping data in a coherent format. This has made it difficult to run programs or computing tasks. The researchers have found a way to preserve electrons, which store the data, longer, which allows a system to process data more coherently and run programs more effectively.
Though still in development, quantum computers could revolutionise the face of computing. In a few seconds, quantum computers can perform tasks not feasible for supercomputers today. Quantum computing uses matter — atoms and molecules — to process massive amounts of tasks at supercomputing speeds because, in quantum computing, data is stored and shared in more states rather than the usual binary states of 0 and 1.
Quantum computing is based on the laws of quantum mechanics, which looks at the interaction and behaviour of matter on atomic and subatomic levels. By solving known issues in quantum computing, researchers are in a race to build a fully operational quantum computer.
There are many quantum computer designs that store data in different ways, says Gavin Morley, one of the authors of the paper and a researcher at the London Centre for Nanotechnology, a joint venture between the University College London and Imperial College London. Morley worked with researchers from several institutions including the University of Utah. The researchers used magnetic states of the electrons to store data.
Quantum bits need to spin to run a program, but sometimes the quality of electrons degrades, sending them into undesirable states — called quantum noise — that could pose a problem as users could lose control of the program running. By applying a certain magnetic field, the researchers used a current to determine the state of an electron without bringing in disturbance, giving them a 5,000% longer life than any other similar experiment to date, Morley says.
The group's research focused on phosphorus atoms in silicon. The best attempts have previously flowed a current past the electrons via small electrical wires, but that has brought in a lot of quantum noise, removing a key advantage of the material, he says.
The researchers hope their work will allow them to build a quantum supercomputer, though it may take time.
"It's impossible to predict when or if a quantum computer will be built," Morley says.
"I would hope to see one in a research lab in the next 15 to 20 years," he says.
But beyond the tough challenges, quantum computers will solve computational problems that plague today's computers, he says. "For example, we could simulate the behaviour of large biological molecules and drugs to find new medicines," he says.
The paper was originally published in Physical Review Letters.