Researchers from UNSW in Sydney demonstrated the lowest noise level in history for a semiconductor quantum bit or cube. The study is published in Advanced Materials.
In order for quantum computers to perform useful calculations, quantum information must have near-100 percent accuracy. Charging noise caused by the imperfection of the material environment in which qubits are located hinders the quantum information encoded on them, affecting the accuracy of information. Scientists have invented how to solve the problem by optimizing the process of making a silicon chip.
“The charge noise level in semiconductor cubes was a major obstacle to achieving the accuracy levels we need for large-scale quantum computers,” explains lead author Ludwik Krantz, PhD and student at the UNSW Center for Quantum Computing and Communication Technologies.
“Our research has shown that we can reduce charge noise to a much lower level by minimizing its impact on our qubits,” said Krantz. “By optimizing the silicon chip manufacturing process, we have achieved a noise level 10 times lower than previously recorded. This is the lowest recorded charge noise among all semiconductor cubes.
Cubits made from electrons placed on atomic qubits in silicon are a promising platform for large-scale quantum computers. However, qubits placed on any semiconductor platform, such as silicon, are sensitive to charge noise. Team research has shown that defects inside the silicon chip or at the interface with the surface contribute significantly to charge noise. By reducing the amount of impurities in the silicon chip and placing atoms away from the surface and interfaces where most of the noise occurs, the command was able to achieve record results.