Leaping forward with quantum technology. — Image by © Tim Sandle.
LEGO for the quantum age? Researchers have created modular superconducting qubits that can be linked with high fidelity. This novel design allows reconfiguration, upgrades, and scalability. It also marks a major step toward fault-tolerant quantum computers.
Given that it is difficult for scientists to build quantum computers monolithically – that is, as a single large unit – the solution is with modularity. This is the approach taken by scientists based at the University of Illinois Grainger College of Engineering.
A qubit, or quantum bit, is the fundamental unit of information in quantum computing, analogous to a classical bit. Unlike classical bits, which can be either 0 or 1, qubits can exist in a superposition of states, allowing them to represent both 0 and 1 simultaneously.
Quantum computing relies on the manipulation of millions of information units called qubits, yet these qubits are difficult to assemble. Further, monolithic superconducting quantum systems are limited in size and fidelity, which predicts scientists’ rate of success in performing logical operations.
The solution developed? Finding modular ways to construct quantum computers.
Much like plastic children’s bricks that lock together to create larger, more intricate structures, scientists can build smaller, higher quality modules and string them together to form a comprehensive system.
Designers of ‘Lego Fortnite’ ensured that all the settings and characters who appear in the videogame could be built in the real world with Lego pieces – Copyright AFP Joseph Prezioso
Connecting up to make big
In trials, this approach to scalable quantum computing was performed by demonstrating a viable and high-performance modular architecture for superconducting quantum processors. The approach expands on previous modular designs and potentially paves the way toward scalable, fault-tolerant and reconfigurable quantum computing systems.
By constructing a system where two devices are connected with superconducting coaxial cables to link qubits across modules, the research team demonstrated ~99% SWAP gate fidelity, representing less than 1% loss. This ability to connect and reconfigure separate devices with a cable while retaining high quality provides novel insight to the field in designing communication protocols.
The research appears in the journal Nature Electronics, titled “A high-efficiency elementary network of interchangeable superconducting qubit devices.”
Improving quantum memeory
In related quantum computing news, Caltech (California Institute of Technology) scientists have made a breakthrough in transforming quantum memory to last 30 times longer than standard.
While superconducting qubits are great at fast calculations, they struggle to store information for long periods. A team at Caltech has now developed a clever solution: converting quantum information into sound waves. By using a tiny device that acts like a miniature tuning fork, the researchers were able to extend quantum memory lifetimes up to 30 times longer than before. This breakthrough could pave the way toward practical, scalable quantum computers that can both compute and remember.
The Caltech scientists used a hybrid approach for quantum memories, effectively translating electrical information into sound so that quantum states from superconducting qubits can survive in storage for a period up to 30 times longer than in other techniques.