Theory Seminar: Crosstalk-Insensitive Trapped-Ion Entanglement through Coupling Matrix Engineering

Vikram Kashyap
University of Maryland
OQS Seminar, at the Seminar Room
Wednesday, July 31, 14:30 CET 

In trapped-ion quantum computing, it is possible for stray light from the addressing laser to illuminate the neighboring ions of the ions undergoing a gate. In entangling gates, this "crosstalk" error results in unwanted non-local entanglement between target and neighbor ions. I will speak about a method for running entangling gates in a manner insensitive to crosstalk. The generation of entanglement in trapped-ion systems is mediated by the motional modes of the ion string. By exciting these modes in particular ratios, we can eliminate the couplings between the target ions and their neighboring ions while retaining the coupling between the two target ions. This allows high-fidelity entangling gates to be run even in the presence of crosstalk. We experimentally demonstrated a simple example of this method on a 3-ion string. The results I will discuss were recently published in a letter: https://journals.aps.org/prl/abstract/10.1103/c6wf-z99k.