A team of physicists is the first to use a simple quantum device to model an experiment in high-energy physics.
Researchers from the Institute for Quantum Optics and Quantum Information at the Austrian Academy of Sciences have used a quantum computer to simulate the spontaneous creation of particle-antiparticle pairs. These kinds of calculations can become too complex to be performed by normal computers.
Quantum computers work much faster than regular computers because they take advantage of a quirk in quantum mechanics. While classical computers use bits that assume the state of 0 or 1, quantum computers use “qubits” that take the state of 0, 1, or a “superposition” of the two.
The team used a system in which four calcium ions were trapped using electromagnetic fields so they could function as qubits. The qubits performed logic operations under the control of laser pulses, with the resulting quantum fluctuations in energy allowing the team to read off mathematical results that showed whether particles and antiparticles were created during a specific simulation.
In this case, the results were relatively simple to confirm using results generated by a classical computer. But the team reckons that if the quantum device could be scaled up, they could use it to investigate problems that lie beyond the scope of current computing systems, such as modeling the strong nuclear force.
Scaling up the hardware, however, is far from straightforward. More power requires more qubits, but linking together enough particles while maintaining their quantum states is difficult. The Canadian company D-Wave claims to have built a quantum computer containing over 1,000 qubits, but there is some debate over whether its behavior is truly quantum.
In the meantime, large companies, small startups, and academics are all trying to crack the puzzle of squeezing more qubits together. When they do, at least we know that physicists will be able to make some use of the things.