UK experts have pioneered Quantum Phononic Links, a new approach that could enable scalable long-distance quantum information transfer across future quantum computing chips.
Researchers at the University of Warwick, working with the National Research Council (NRC) Canada, have unveiled a new concept that could overcome one of the biggest technical barriers to large-scale quantum computing: efficiently transferring quantum information between qubits across an entire semiconductor chip.
Dr Maksym Myronov, Department of Physics, University of Warwick, explained: “One of the key challenges in quantum computing is long-range qubit connectivity.
“Our work introduces a new concept in which phonons act as a quantum bus, enabling distant qubits to exchange quantum information while remaining fully compatible with semiconductor technology.”
Published in APL Quantum, the team showcases Quantum Phononic Links (QPLs), a proposed communication method that uses sound-like vibrations, known as phonons, to transmit quantum information between qubits separated by long distances. The approach is designed to support future quantum processors containing millions of qubits.
If successfully developed, the technology could provide a more scalable and cost-effective alternative to existing methods for connecting distant qubits. Because it is compatible with established semiconductor manufacturing processes, it could also simplify the production of commercial quantum computing hardware.
Addressing a key quantum computing challenge
Current quantum processors typically allow direct communication only between neighbouring qubits.
While this architecture is sufficient for small-scale experimental devices, it presents a significant obstacle for the development of practical quantum computers capable of solving complex scientific and industrial problems.
Future quantum systems are expected to require millions of qubits distributed across semiconductor chips measuring up to 300mm in diameter. Efficiently moving quantum information between these distant qubits remains one of the major engineering challenges facing the industry.
The Warwick-led research proposes using phonons, tiny mechanical vibrations that travel through solid materials, as a built-in communication network.
Rather than relying solely on adjacent connections, the concept would enable qubits positioned anywhere on the chip to exchange quantum information through carefully controlled vibrations.
Specialised semiconductor material enables communication
The proposed QPLs rely on a specialised material known as compressively strained germanium on silicon (cs-GoS), developed at the University of Warwick using advanced epitaxial growth techniques.
Within this material, qubits are highly responsive to minute mechanical vibrations travelling through the thin germanium layer.
By engineering these vibrations with precision, the researchers demonstrate that, in principle, quantum information could be transmitted between qubits regardless of whether they are located next to one another or separated across the full surface of a semiconductor wafer.
This built-in communication mechanism could provide a more efficient way to coordinate the vast numbers of qubits needed for fault-tolerant quantum computing.
Simpler path towards commercial quantum processors
Existing approaches for linking distant qubits often depend on microwave systems or externally generated surface acoustic waves, adding complexity and additional hardware to quantum chips.
The QPL concept instead integrates the communication mechanism directly into the semiconductor material hosting the qubits. This removes the need for separate communication components while remaining compatible with conventional semiconductor fabrication techniques.
Although the concept remains at the research stage, it offers a promising framework for creating compact, scalable quantum processors.
By embedding long-range communication directly within the chip architecture, QPLs could help accelerate the development of next-generation quantum computers capable of processing quantum information at an unprecedented scale.
