Researchers at the University of Innsbruck, Austria, have built the smallest quantum computer yet based on industry standards. The success of the new devices illustrates that quantum computers will soon be ready for installation in data centres alongside classical computers.
“Our quantum computing experiments usually fill 30 to 50-square-metre laboratories,” said Dr Thomas Monz, who belongs to the university’s department of experimental physics. “We were now looking to fit the technologies developed here in Innsbruck into the smallest possible space while meeting standards commonly used in industry.”
Monz and his colleagues built a demonstrator for a compact trapped-ion quantum computer. This type of quantum computer (to state with great simplicity) confines and suspends charged particles using electromagnetic fields, with qubits corresponding with the stable electronic states of each particle. The fundamental operations of quantum computing have been demonstrated with great accuracy using these systems.
Compacting a trapped-ion quantum computer required miniature versions of each individual building block. The researchers acquired the centrepiece of the system (the ion trap within a vacuum chamber) from a spin-off from the university focused on building a commercial quantum computer. A particular challenge in the build was ensuring the stability of the quantum computer; quantum devices are extremely sensitive to the slightest external disturbances, which cause decoherence and disruption to operation. However, the researchers were able to apply the necessary quality standard even for their miniaturised device.
The compact quantum computer can be operated autonomously and will soon be programmable online.
Another decisive factor for the industrial use of quantum computers is the number of available qubits. The Innsbruck physicists were able to run the quantum computer with 24 fully functional qubits – individually controlling and entangling 24 trapped ions with their device – meeting a recent target set by the German government with surprising speed.
“By next year, we want to be able to provide a device with up to 50 individually controllable quantum bits,” said Monz.
Last month, the German government announced that it would spend billions of euros to support the development of the country’s first quantum computer and other quantum technologies. The government hopes to build a competitive quantum computer in just five years while nurturing a network of companies to develop applications.
In 2019, Google engineers published a paper stating that they had achieved “quantum supremacy” (a milestone referring to the ability of quantum computer to perform calculations impossible for classical computers) with a quantum computer with 54 qubits.