Quantum computers, devices that process information leveraging quantum mechanical effects, could tackle some tasks that are difficult or impossible to solve using classical computers. These systems represent data as qubits, units of information that can exist in multiple states at once, unlike the bits used by classical computers that represent data using binary values (“0” or “1”).

Some of the quantum computers developed in recent years store quantum information in the spin (i.e., intrinsic angular momentum) of electrons or nuclei that are trapped in small semiconductor-based structures, known as quantum dots. For these devices to operate reliably, however, engineers need to be able to precisely measure the quantum states of the spin qubits they rely on, a process that is known as qubit readout. It would also be advantageous for these states to be precisely measured in a way that is architecturally compact, or in other words, using space-efficient hardware as opposed to numerous bulkier components.

Researchers at Quantum Motion and University College London (UCL) recently introduced a new approach to clearly read out the states of spin qubits leveraging high-frequency electrical signals. This method, introduced in a paper published in Nature Electronics, was developed by Jacob F. Chittock-Wood and his colleagues while he was completing his Ph.D. at UCL.