Abstract: Aspects of the present disclosure are directed to fabrication methods for analogue quantum systems (AQSs). Further aspects of the present disclosure are directed to methods for solving computational problems using an AQS. Methods for fabricating an AQS include generating a Hamiltonian based on a computational problem, which may be an optimization problem or a simulation problem. Further, the method includes identifying AQS fabrication parameters based on one or more identified measurement methods and the Hamiltonian. Lastly, an AQS can be fabricated based on the identified fabrication parameters. An AQS may be used inter alia to simulate a battery or interfaces.

Abstract: Quantum processing element and method to perform logic operations on a quantum processing element are disclosed. The quantum processing element includes: a semiconductor, a dielectric material forming an interface with the semiconductor, a plurality of dopant dots embedded in the semiconductor, each of the dopant dots comprising one or more dopant atoms and one or more electrons or holes confined within the dopant dots, wherein spin of an unpaired electron or hole of each dopant dot forms at least one qubit. The method includes the step of: controlling orientation of nuclear spins of the one or more dopant atoms in a pair of dopant dots and/or controlling a hyperfine interaction between nuclear spins of one or more dopant atoms and electron or hole spins of the unpaired electron or hole in the pair of dopant dots to perform a quantum logic operation on a corresponding pair of qubits.

Abstract: A quantum processing system and method of operating the same are disclosed. The system includes a first qubit comprising a first unpaired electron bound to a first pair of donor clusters embedded in a semiconductor substrate at a distance from the semiconductor surface. each donor cluster in the first pair of donor clusters including at least one donor atom. The system further includes a second qubit comprising a second unpaired electron bound to a second pair of donor clusters embedded in the semiconductor substrate at a distance from the semiconductor surface. each donor cluster in the second pair of donor clusters including at least one donor atom. In addition, a microwave resonator is located between the first qubit and the second qubit, wherein a first end of the microwave resonator is coupled to the first qubit and a second end of the microwave resonator is coupled to the second qubit. A photon of the microwave resonator couples the first qubit and the second qubit.

Abstract: A quantum bit, quantum processing element, and one or more large-scale quantum processing systems are disclosed. the quantum bit includes: a first quantum dot embedded in the semiconductor substrate, the first quantum dot comprising a first donor atom cluster and a second quantum dot embedded in the semiconductor substrate, the second quantum dot comprising a second donor atom cluster. The first and second quantum dots share a single electron, and the quantum bit is electrically controlled utillising the hyperfine interaction between the single electron and one or more nuclear spins present in the first and second donor atom clusters.

Abstract: The present disclosure relates to a kinetic inductance parametric amplifier that comprises an input port arranged to receive a pump tone, a DC bias and input signal; an output port arranged to provide an amplified version of the input signal; a tunable stepped-impedance assembly arranged to attenuate and/or filter predetermined frequency bands; and a high kinetic inductance line. The tunable stepped-impedance assembly is tuned at a frequency that allows for the amplifier to resonate at a predetermined frequency and a pump tone with a frequency higher than the input signal and a DC biasing signal to be transmitted to the high kinetic inductance line.

Abstract: Aspects of the present disclosure are directed to quantum processing systems that include a plurality of donor atom qubits positioned in a semiconductor substrate. The system also comprises a plurality of control gates configured to control the donor atom qubits. The system further comprises an SLQD charge sensor fabricated on/in the semiconductor substrate. The SLQD charge sensor is configured to sense spin-states of two or more donor atom qubits, which are positioned within a sensing range of the SLQD charge sensor.

Abstract: A quantum processing element is disclosed. The element includes a semiconductor substrate, a dielectric material forming an interface with the semiconductor substrate, and a donor molecule embedded in the semiconductor. The donor molecule includes a plurality of dopant dots embedded in the semiconductor, each dopant dot includes one or more dopant atoms, and one or more electrons/holes confined to the dopant dots. A distance between the dopant dots is between 3 and 9 nanometres.

Abstract: A method for readout of a singlet-triplet qubit in a donor based quantum processing element is disclosed. The method includes: initialising the singlet-triplet qubit in a ground state |G; performing a shelving readout; using a final measured charge configuration of the singlet-triplet qubit to determine information about a current Zeeman energy difference; and using the information about the current Zeeman energy difference to adjust mapping of the shelving readout.

Abstract: One-dimensional and two-dimensional arrays of qubits are disclosed. The one-dimensional array includes two or more double-quantum dots embedded in silicon, the two or more double-quantum dots arranged in an Echelon formation, such that the distance between the two or more double-quantum dots is approximately 40 nm and the distance between the two quantum dots in each double-quantum dot is approximately 12 nm; two or more reservoirs to load electrons to the corresponding two or more double-quantum dots to form singlet-triplet qubits in each double-quantum dot; and two or more gates for controlling the formed singlet-triplet qubits. The two-dimensional array of qubits includes two or more layers of vertically-stacked one-dimensional arrays of qubits.

Abstract: A method for measuring the spin of an electron in a quantum dot that is tunnel coupled to a reservoir is disclosed. The method includes measuring a spin state of the injected electron while applying a ramped detuning for a time period.