The silicon quantum computer chip used in this study. Photo credit: RIKEN Researchers from RIKEN and QuTech – a collaboration between TU Delft and TNO – have reached an important milestone in the development of a fault-tolerant quantum computer. They were able to demonstrate two-qubit gate accuracy of 99.5 percent — higher than the 99 percent considered the threshold for building fault-tolerant computers — using electron spin qubits in silicon, which show…