Abstract: A system and method for transfer of signals between an inside of a cryogenic system and an external environment including at least one optical source (e.g., a laser) for generating optical input signals and at least one fibre for transferring modulated optical signals to the inside of the cryogenic system and receiving optical output signals from the inside of the cryogenic system. A plurality of detectors, located in the external environment, is used for detecting the optical output signals and are connected to the fibre. A plurality of first transducers converts the modulated optical signals to microwave input signals and a plurality of second transducers converts the microwave input signals to optical output signals. A first microwave impedance matching resonator is connected to the plurality of first transducers and a second microwave impedance matching resonator is connected to the plurality of second transducers.

Abstract: A processing element for a quantum processing apparatus is disclosed. The processing element includes: a silicon substrate; a dielectric material, wherein the silicon substrate and the dielectric material form an interface; an electrode formed on the dielectric material for isolating one or more electrons in the silicon substrate to form a quantum dot; a group IV atom having a nuclear spin located in the wavefunction of the one or more electrons, the nuclear spin of the group IV atom entangled with the one or more electrons; and a control arrangement for controlling a quantum property of the quantum dot and/or the nuclear spin to operate as a qubit.