Think of an orchestra – with many musicians playing a range of instruments to a set musical score, led by a conductor. Each instrument holds the potential for individual sound, depending on the degree of skill of the musician playing the instrument.

The role of the conductor is to bring alignment of all these individual instruments, lead the activity, setting the tempo, the volume and the dynamics and bring the musical score to life.

Qubits operate like individual musical instruments, with each qubit, very fragile and operating independently. In the case of a large number of qubits, known as an array, the ability to control qubits at scale is essential for scalable fault tolerant computing.

Individual qubit control commonly relies on spectral selectivity, where individual microwave signals of distinct frequencies are used to address each qubit.

Semiconductor spin qubits represent a promising platform for future large-scale quantum computers owing to their excellent qubit performance, as well as the ability to leverage the mature semiconductor manufacturing industry for scaling up to millions of qubits on a chip.

Furthermore, as quantum processors scale up, the approach of managing each qubit’s performance as distinct, will be beset with issues that can impact qubit performance, such as frequency crowding, control signal interference and unfeasible bandwidth requirements.

The team at Diraq are focused on designing and engineering excellent qubit performance in the silicon-CMOS based platform – and this entails showcasing reliable operational coherence and synchronicity and a steadfast commanding conductor driving exceptional performance.

With this approach in mind, the Diraq team applied global control via a single microwave field (known as global control field) together with individual addressing via local electrodes. Another beneficial aspect of our approach related to the global control field, which was generated off-chip, freeing up space on the chip and simplifying control signal routing.

The results demonstrated that two degenerate spins can be driven synchronously with a single global field and universally controlled electrically by local electrodes.

In short, the research confirmed that a global control scheme based on dressed degenerate qubits tackles the fragility of qubits and overcomes frequency crowding while offering a prospect for scalability of our Si CMOS qubit technology to enable large-scale quantum computing.
To put it simply, we successfully developed a method to ensure excellent sustainable performance for a large number of qubits, that can operate in synch.  

Our CEO and Founder, Andrew Dzurak said – “Diraq has been working on a range of different approaches to bring a cohesive qubit performance together. This research is like a dress rehearsal – as we build towards opening night performance. The results support Diraq’s leading role in developing a reliable global qubit control strategy required for semiconductor spin qubits - essential for scalable, fault-tolerant quantum computing.”

The research, led by Ingvild Hansen and Henry Yang, was recently published in the journal Nature Communications and is available here: Entangling gates on degenerate spin qubits dressed by a global field and the recent announcement here.

Bravo!