Compression of a circuit that has an initial volume of 882 using the proposed method. The reduced circuit has a volume of 420, less than half its original volume.
A major technical challenge for any practical, real-world quantum computer comes from the need for a large number of physical qubits to deal with errors that accumulate during computation. Such quantum error correction is resource-intensive and computationally time-consuming. But researchers have found an effective software method that enables significant compression of quantum circuits, relaxing the demands placed on hardware development.
Quantum computers may still be far from a commercial reality, but what is termed ‘quantum advantage’—the ability of a quantum computer to compute hundreds or thousands of times faster than a classical computer-has indeed been achieved on what are called Noisy Intermediate-Scale Quantum (NISQ) devices in early proof-of-principle experiments.