Cited research: Phys. Rev. Lett. doi:10.1103/PhysRevLett.104.180501 (2010)

Semiconducting chips are fast approaching classical limits. Electrical circuits have become atomically thin, causing errors in their logic gates when current leaks out. However, quantum manipulations of atoms and small molecules offer a way around these limits.

Kenji Ohmori at the Institute for Molecular Science in Okazaki, Japan, and his colleagues describe a new logic component that could be used in quantum-information science. It is an ultra-fast Fourier transform, a standard mathematical tool used in electronic signal processing to convert signals from one function to another.

The team excited an iodine molecule such that its quantum vibrations executed Fourier transforms in just 145 femtoseconds — several orders of magnitude faster than is possible in today's computer chips. The technique shows another way in which a quantum computer could, in theory, be both faster and more accurate than a classical computer. E.H.