Unlocking Scalable Quantum Computing with Terahertz Generation QuanTera
Funder: Engineering and Physical Sciences Research Council (EPSRC)
Lead partner: UCL
Partners: PHIX, Science and Technology Facilities Council - Rutherford Appleton Laboratory, University of Bristol including HIMR
Lead academic: Dr James Seddon
Project amount: £1,816,820
Research themes: Quantum Computing; Control & Signal Processing
Project period: 1 August 2025 – 31 July 2030
Project description: Quantum computers could be useful for simulating biological and chemical reactions beyond the reach of traditional computers. Among many other advances, this will revolutionise medicine and materials discovery.
Various technologies are explored for quantum computing. For example, superconductors used by Google and IBM rely on qubits, two-level quantum systems with distinct energy spacing. To solve real-world problems arrays of millions of qubits are needed1. This current implementation, operating at microwave frequencies (a few GHz), demands colder temperatures than even outer space - and the only refrigerators that can support this have limited cooling power. Higher frequencies would allow an increased working temperature, although different superconducting materials would also be needed. Connecting copper cables for controlling the qubit arrays electrically introduces unwanted heat, limiting the refrigerator’s capacity to support around 1000 qubits.
I aim to develop the enabling technology needed to realise a scalable quantum computer operating at THz frequencies. I propose two solutions: replacing electrical cables with optical fibres for control-signal distribution, and elevating working frequencies to the THz range. Generating high frequencies is challenging; however, I have devised a light-based system to achieve this leap, enabling operation at higher temperatures. These shifts allow the use of cooling technologies with greater power, potentially scaling the quantum technology to hundreds of millions of qubits.
