Noisy Quantum Computers Could Be Good for Chemistry Problems

Scientists and researchers have long extolled the extraordinary potential capabilities of universal quantum computers, like simulating physical and natural processes or breaking cryptographic codes in practical time frames. Yet important developments in the technology—the ability to fabricate the necessary number of high-quality qubits (the basic units of quantum information) and gates (elementary operations between qubits)—is most likely still decades away. However, there is a class of quantum devices—ones that currently exist—that could address otherwise intractable problems much sooner than that. These near-term quantum devices, coined Noisy Intermediate-Scale Quantum (NISQ) by Caltech professor John Preskill, are single-purpose, highly imperfect, and modestly sized. As the name implies, NISQ devices are “noisy,” meaning that the results of calculations have errors, which in some …