Quantum Pixel (QuPix)

Quantum computing is poised to be a driver of innovation in the next decade. Its information processing capabilities will radically accelerate drug discovery, improve online security, and will boost artificial intelligence algorithms. Building a quantum computer promises to have a major positive impact on society. However, current qubit numbers are insufficient to realise quantum computation of significant practical use. For instance, simulations of simple materials require hundreds or thousands of qubits, while for the most economically and socially significant algorithms many millions or billions will be required. An industry manufacturable technology that can achieve that level of integration is required to move from the $1.1 B market of small-scale quantum processors to the projected $130 B for large-scale quantum computers.

Quantum Motion is tackling the challenge by building qubits using silicon transistors, the technology capable of integrating more elements in a single chip than people on the surface of Earth. Silicon spin qubits embedded in silicon transistors have great scalability prospects since they can leverage the technology underpinning today's semiconductor industry. However, qubits are not exactly transistors and small modifications are needed to exploit the quantum nature of these devices. For example, the readout circuitry currently used to read the quantum state of a silicon spin qubit is orders of magnitude larger than the transistors themselves posing a bottleneck for scaling.

Project QuPix enters at the core of this idea and focuses on developing an integrated and industry manufacturable qubit cell, including the circuitry surrounding the qubit dedicated to the readout, with an unparalleled small footprint, a million times smaller than the most scalable alternative quantum hardware. Our scalable approach is designed to have a qubit cell density of 10^8 cm^-2, offering a platform to cram on a chip the size of a fingerprint the qubit numbers needed to tackle society's most demanding computational problems placing the UK at the forefront of an industrial race to realise an integrated silicon-based quantum computer.

In the path to scaling, the QuPix cells can offer technological applications today. In the same way that the first transistors were used for amplification purposes until digital computing got traction, we will use a single QuPix to demonstrate a new kind of quantum-limited amplifier: a silicon-based an amplifier adding the minimal noise allowed by the laws of quantum mechanics capable of entering the market due to its cost-effective industrial manufacturability, compactness, and resilience against magnetic fields.