Researchers from the University of Sussex and Universal Quantum have demonstrated for the first time that quantum bits (qubits) can directly transfer between quantum computer microchips and demonstrated this with record-breaking speed and accuracy. This breakthrough resolves a major challenge in building quantum computers large and powerful enough to tackle complex problems that are of critical importance to society.
We show how one can make use of a wide range of quantum control methods to raise fidelities and robustness of two-qubit gates with trapped ions.
The paper was published on 27 September 2022 in Journal of Physics B: Atomic, Molecular and Optical Physics.
Manuscript: Quantum Control Methods for Robust Entanglement of Trapped Ions.
We present the demonstration of a quantum matter-link in which ion qubits are transferred between adjacent QC modules. Ion transport between adjacent modules is realised at a rate of 2424 1/s and with an ion-transfer fidelity in excess of 99.999993%. Furthermore, we show that the link does not measurably impact the phase coherence of the qubit. The realisation of the quantum matter-link demonstrates a novel mechanism for interconnecting quantum computing modules. This achieves a key milestone for the implementation of modular quantum computers capable of hosting millions of qubits. Published on 8 February in Nature Communications.
University of Sussex Press Release
Manuscript: A High-Fidelity Quantum Matter-Link Between Ion-Trap Microchip Modules
We have determined how a quantum computer could break the encryption of Bitcoin and simulate the FeMo-co molecule, a crucial molecule for Nitrogen fixation. We show that in certain situations, architectures with considerably slower code cycle times will still be able to reach desirable run times, provided enough physical qubits are available. Four years ago, we estimated that a trapped ion quantum computer would need a billion physical qubits to break RSA encryption equating to a size 100m2. With innovations across the board, the size of such a quantum computer would now just need to be 2.5m2.
The paper was published on 25 Jan 2022 in AVS Quantum Science.
Manuscript: The Impact of Hardware Specifications on Reaching Quantum Advantage in the Fault Tolerant Regime
Press release: Sussex Scientists Reveal how Quantum Computing can Break Bitcoin and Help Tackle World Hunger
Professor Winfried Hensinger presented his personal journey spanning three continents and four countries, in a bid to achieve his goal of building a scalable quantum computer. He discussed the future of quantum computing and quantum technologies in academia and industry at the Careers in Quantum online event on 3 June 2021, organised by the University of Bristol Quantum Engineering Centre for Doctoral Training. You can watch the advice he gave here.
We propose a new microwave gate which uses the intrinsic J-coupling of ions in a static magnetic gradient. The gate is virtually insensitive to common amplitude noise of the microwave fields and enables high fidelities despite qubit frequency fluctuations, while the J-coupling interaction’s inherent robustness to motional decoherence is retained. Errors far below the fault-tolerant threshold can be achieved at high initial temperatures, negating the requirement of sideband cooling below the Doppler temperature.
Manuscript : Robust Entanglement by Continuous Dynamical Decoupling of the J-Coupling Interaction
Microfabricated ion-trap devices offer a promising pathway towards scalable quantum computing. Addition of on-chip features, however, increases the power dissipated by components such as current-carrying wires and digital-to-analogue converters (DACs). Presented here is the development of a modular cooling system designed for use with multiple ion-trapping experiments simultaneously enabling efficient cooling to 70K while provide significant and scalable cooling power.
Manuscript: A Scalable Helium Gas Cooling System for Trapped-Ion Applications
We are happy to announce a strategic partnership with full stack quantum computing company Universal Quantum. Universal Quantum is a spin-out from the Sussex Ion Quantum Technology group. This partnership will allow us to develop and construct practical quantum computers. More information can be found here.
