Record-breaking UQ Connect technology

With a single wafer holding just a few thousand qubits at most, modularity is critical to scale to millions of qubits. One proposed method uses photonic interconnects, with optical fibres connecting different quantum computing modules. The connection speeds of this extremely complicated technology after years of intense research are low and no simple engineering solution is yet available. This, therefore, provides a potentially unsurmountable bottleneck when scaling up.

We take a completely different approach to modularity, using electric field links between adjacent quantum computing modules. As well as using much simpler engineering, our UQ Connect links between modules are orders of magnitude better than alternative techniques.

UQ Connect has achieved a world record connection rate (2424/s) and connection fidelity (>99.999993%) between two trapped ion quantum computer modules.

Fully integrated trapped ion quantum computer modules

With a single wafer holding just a few thousand qubits at most, modularity is critical to scale quantum computers to the million-qubit range.

Our modules feature a fully connected trapped ion qubit system and integrated qubit control technology. This capitalizes on the wealth of expertise that has come out of the development of the silicon microchips used in conventional computers. So, our modules can be manufactured using established silicon fabrication techniques.

The result is fully integrated self-contained electronic quantum computing modules.

Electronic quantum gates

Trapped ion quantum computers generally use pairs of laser beams aligned to the position of individual ions to execute quantum gates. This requires alignment accuracy to a fraction of the width of a human hair. But imagine trying to align millions of laser beams with such incredible accuracy, while stabilising each one’s power, position and phase – where the slightest deviation stops the quantum computer from working.

We use a much simpler electronic gate technology where a combination of voltages is applied to our microchip.

The best part of this gate scheme is that it doesn’t matter if we have ten or ten million qubits, the number of microwave sources is fixed allowing for dramatically simplified scaling.

A temperature that scales

Many other quantum computing platforms require cooling close to milli-Kelvin temperatures (i.e. absolute zero or -273C). But with such limited cooling power available at that temperature, scaling to millions of qubits is incredibly hard to achieve.

We take a different approach. Our technology only requires cooling to 70K, providing ample cooling power which scales to millions of qubits.

Trapped ion qubits

We use individual charged atoms – ions – as our qubits.

Because the qubits are naturally identical, well isolated from the environment and easily controllable, ‘trapped ion’ quantum computing is the most mature quantum computing technology.

Each ion levitates above the surface of a silicon microchip. Using our design, ions can effectively move around the quantum computer and ‘talk’ to one another. Such all-to-all connectivity is important to unlock the true potential of quantum computing at the million-qubit scale.

This high connectivity may allow more efficient quantum error correction methods to be used. Practically this means fewer qubits can provide the same computational power.

Currently, trapped ion quantum computing also holds world records in almost all the important specifications, such as errors for single / two-qubit quantum gates, connectivity and decoherence time.

Practical engineering focus

There are many theories about how to build a million-qubit quantum computer, but none of them has a ‘nuts and bolts’ delivery plan – except ours. In 2017 we drafted the first practical blueprint to build a quantum computer with millions of qubits, supported by realistic engineering considerations. It underwent years of scrutiny before publication, and its authors include some of the leading experts from around the world. You can read more about it here.

At Universal Quantum, we don’t just deliver the physics – we also develop truly innovative engineering solutions. Humanity needs a quantum computer with millions of qubits and we’re bringing together a world-leading, truly interdisciplinary team to build exactly that.