SUPERCONDUCTING DOT/ANTI-DOT FLUX QUBIT BASED ON TIME-REVERSAL SYMMETRY BREAKING EFFECTS

A solid-state quantum computing structure includes a dot of superconductive material, where the superconductor possesses a dominant order parameter with a non-zero angular momentum and a sub-dominant order parameter that can have any pairing symmetry. Alternately a solid-state quantum computing structure includes an anti-dot, which is a region in a superconductor where the order parameter is suppressed. In either embodiment of the invention, circulating persistent currents are generated via time-reversal symmetry breaking effects in the boundaries between superconducting and insulating materials. These effects cause the ground state for the supercurrent circulating near the qubit to be doubly degenerate, with two supercurrent ground states having distinct magnetic moments. These quantum states of the supercurrents store quantum information, which creates the basis of qubits for quantum computing. Writing to the qubits and universal single qubit operations may be performed via the application of magnetic fields. Read-out of the information may be performed using a SQUID microscope or a magnetic force microscope.