Evan Reed (IonQ), QISE Seminar: Flipping Molecules: An Experimental Demonstration of Dipole-Phonon Quantum Logic

Abstract

Trapped atomic ions are one of the leading candidates for large-scale quantum technologies, and many decades of research have gone into developing the techniques to coherently control the quantum states of atomic ions to make them a viable platform for engineering quantum technologies. The applications range from computation to communication networks to sensing. Molecular ions, however, remain under-researched. While their wealth of internal states makes them interesting candidates for quantum technologies, it also makes them difficult to control. Here, we demonstrate that by using the electric potential of the ion trap we can coherently, and without lasers, induce a transition between two internal states of a single molecular ion (CaO+) by means of a Jaynes-Cummings-type interaction. Then, we use a co-trapped atomic ion (Ca+) to herald and measure the interaction via quantum logic spectroscopy. This procedure, named dipole-phonon quantum logic (DPQL), enables state preparation and measurement of quantum information encoded in a molecular ion. Here, I present the first demonstration of DPQL. We have shown the interaction signals to have a lower bound on the statistical significance as high as 4.92σ and posterior probability greater than 99%. 

Bio

Evan Reed is a physicist on the Science Team at the quantum technology company IonQ. He grew up in Georgia in the foothills of southern Appalachia, and he attended the Georgia Institute of Technology for his BS in physics. There, he trained in ion trapping under the guidance of Prof. Ken Brown. As Evan graduated from GT, the Brown Lab moved from GT to Duke University. Evan rejoined the Brown lab at Duke as a PhD student in the department of electrical and computer engineering where he performed research in the coherent control of trapped molecular ions. Evan defended his dissertation in May of 2024 after which he joined IonQ and moved to Seattle. At IonQ, he now works on the team that builds the prototypes of the most advanced generation of quantum computers and performs technology development for future generation systems.