Tue February 7, 2023 4:00 pm

CUA Seminar – Kenji Ohmori: Ultrafast quantum simulation and quantum computing with ultracold atom arrays

Location:Harvard Jefferson 250
Kenji Ohmori, Institute for Molecular Science, National Institutes of Natural Sciences (NINS), Japan
Ten Minute Talk:"Cavity QED with spin ensembles" by Matt Trusheim

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 [1-6]. We first applied our ultrafast coherent control with attosecond precision [2,3] 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 [1]. 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 [4-6].

In this ultrafast quantum computing, very recently, we have succeeded in executing a controlled-Z gate in only 6.5 nanoseconds [6]. 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.


[1] N. Takei et al., Nature Commun. 7, 13449 (2016).
Highlighted by Science 354, 1388 (2016); IOP (2016).
[2] H. Katsuki et al., Acc. Chem. Res. 51, 1174 (2018).
[3] C. Liu et al., Phys. Rev. Lett. 121, 173201 (2018).
[4] M. Mizoguchi et al., Phys. Rev. Lett. 124, 253201 (2020).
[5] V. Bharti et al., arXiv:2201.09590 (2022).
[6] Y. Chew et al., Nature Photonics 16, 724 (2022). (Front Cover Highlight)

Event type: