(Centre for Quantum Computation & Communication Technology) A team led by UNSW scientists have significantly increased the coherence time of a spin-orbit qubit in silicon, allowing them to preserve quantum information for longer. These results open up a new pathway to scale silicon quantum computers.
Australian scientists have investigated new directions to scale up qubits - utilising the spin-orbit coupling of atom qubits - adding a new suite of tools to the armory.Spin-orbit coupling, the coupling of the qubits' orbital and spin degree of freedom, allows the manipulation of the qubit via electric, rather than magnetic-fields.Using the electric dipole coupling between qubits means they can be placed further apart, thereby providing flexibility in the chip fabrication process.In one of these approaches, published in Science Advances, a team of scientists led by UNSW Professor Sven Rogge investigated the spin-orbit coupling of a boron atom in silicon."Single boron atoms in silicon are a relatively unexplored quantum system, but our research has shown that spin-orbit coupling provides many advantages for scaling up to a large number of qubits in quantum computing" says Professor Rogge, Program Manager at the Centre for Quantum Computation and Communication Technology (CQC2T).Following on from earlier results from the UNSW team, published last month in Physical Review X, Rogge's group has now focused on applying fast read-out of the spin state (1 or 0) of just two boron atoms in an extremely compact circuit all hosted in a commercial transistor.