A professor at the University of Sussex says he has the first practical blueprint for a quantum computer capable of solving problems that could take billions of years for a classical computer to compute. Oh yeah?
A quantum computer (QC) uses qubits instead of classic binary digits, and each qubit is in a quantum state between zero and one. QCs can perform a huge number of calculations simultaneously by harnessing this superposition phenomenon along with quantum entanglement. Ultimately, the machines will be able to do things like factor very large composite numbers, which classic computers struggle to do quickly.
This will see QCs complementing binary computers in HPC applications – we won't be using them to compose emails just yet.
Professor Winfried Hensinger is head of a team that has published an open-access paper in the Science Advances journal. He is quoted as saying: "For many years, people said that it was completely impossible to construct an actual quantum computer. With our work we have not only shown that it can be done but now we are delivering a nuts-and-bolts construction plan to build an actual large-scale machine."
The design involves multiple trapped ion-based scalable quantum computing modules with an architecture based on long-wavelength radiation quantum gates. Hensinger's team say modules could be built using silicon microfabrication techniques that are within reach of current technology. A high-threshold surface error correction code can be implemented in the architecture to execute fault-tolerant operations.
Inter-module communications use overlapping electronic fields and charge atoms (ions), and take place 100,000 times faster than current state-of-the-art fibre link technology, which could refer to 16Gbps Fibre Channel – imagine 1,600,000Gbps. However, the team says alternate inter-module comms schemes using photonic interconnects could be used.
Hensinger design schematic of octagonal UHV chambers connected together. Each chamber is 4.5 × 4.5 m2 large and can hold >2.2 million individual X-junctions placed on steel frames
D-Wave has a 2,000-qubit quantum computer processor. Google is also looking at quantum computing. Hensinger's paper makes no reference to these so comparisons can't be drawn unless you are a quantum mechanics person and understand the science and technology involved.
Hensinger's team** involves scientists from Sussex University, Google (USA), Aarhus University (Denmark), RIKEN (Japan) and Siegen University (Germany), and is now building a prototype. We don't have any timescales for this, but what enormous and enthralling research fun it must be. ®
*Annealing is a metallurgy and material sciences term meaning slow cooling, and is used to avoid brittleness and increase strength and ductility in heated metal.
**Heninger's team's work has been supported by the Engineering and Physical Sciences Research Council (EPSRC) through the UK Quantum Technology Hub on Networked Quantum Information Technologies, and the government-backed UK National Quantum Technology Programme.