CQE Seminar: Kenji Ohmori, Institute for Molecular Science in Japan

Many-body correlations drive a variety of important quantum phenomena and quantum machines including superconductivity and magnetism in condensed matter as well as quantum computers. Understanding and controlling quantum many-body correlations is thus one of the central goals of modern science and technology. My research group has recently pioneered a novel pathway towards this goal by exciting strongly interacting ultracold Rydberg atoms, far beyond the Rydberg blockade regime, by using an ultrafast laser pulse. We first applied our ultrafast coherent control with attosecond precision to a random ensemble of those Rydberg atoms in an optical dipole trap, and successfully observed and controlled their strongly correlated electron dynamics on a sub-nanosecond timescale. This new approach is now applied to arbitrary atom arrays assembled with optical lattices or optical tweezers that develop into a pathbreaking platform for quantum simulation and quantum computing on an ultrafast timescale.

In this ultrafast quantum computing, very recently, we have succeeded in executing a controlled-Z gate in only 6.5 nanoseconds. This is the fastest record of a controlled gate, a conditional two-qubit gate essential for quantum computing, faster than any other controlled gates with cold-atom hardware by two orders of magnitude. It is also two orders of magnitude faster than the noise from the external environment and operating lasers, whose timescale is in general 1 microsecond or slower, and thus can be safely isolated from the noise.

CQE members and partners are invited to join. If you are a CQE member or partner and would like to attend virtually, please email quantum@uchicago.edu.