Quantum chip concept aims to improve scalability
Author: Joe Peck
Researchers at The University of Warwick and Canada’s National Research Council (NRC) have proposed a new chip architecture that could address one of the main barriers to scaling quantum computers by enabling communication between qubits over much greater distances.
Published in APL Quantum, the research introduces the concept of Quantum Phononic Links (QPLs), which use sound-like vibrations, known as phonons, to transfer quantum information between qubits located across a semiconductor chip.
The researchers say the approach could help overcome a limitation of current quantum chips, where qubits typically communicate only with neighbouring qubits, as future large-scale quantum computers are expected to require communication between millions of qubits distributed across an entire chip.
Maksym Myronov, Department of Physics at The University of Warwick, says, “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.”
New material supports long-range qubit communication
The proposed architecture is based on compressively strained germanium on silicon (cs-GoS), a material developed at The University of Warwick using epitaxial growth techniques.
According to the researchers, qubits within the material are highly sensitive to vibrations travelling through the germanium layer. By controlling these vibrations, quantum information could, in principle, be transferred between qubits positioned either adjacent to one another or separated across semiconductor chips measuring up to 300mm in diameter.
The team says this differs from other approaches that rely on microwaves or externally generated surface acoustic waves, which typically require additional hardware and more complex chip designs.
Instead, QPLs are integrated directly into the semiconductor material hosting the qubits. The researchers suggest that compatibility with existing semiconductor manufacturing processes could support the development of more scalable quantum processors in the future.
