Fast dynamical decoupling of the Molmer-Sorensen entangling gate

• Main Authors: Manovitz, Tom, Rotem, Amit, Shaniv, Ravid, Cohen, Itsik, Shapira, Yotam, Akerman, Nitzan, Retzker, Alex, Ozeri, Roee
• Format: Journal Article
• Language: English
• Published: 12-06-2017
• Subjects: Physics - Atomic Physics; Physics - Quantum Physics
• DOI: 10.48550/arxiv.1706.03468

Phys. Rev. Lett. 119, 220505 (2017) Engineering entanglement between quantum systems often involves coupling
through a bosonic mediator, which should be disentangled from the systems at
the operation's end. The quality of such an operation is generally limited by
environmental and control noise. One of the prime techniques for suppressing
noise is by dynamical decoupling, where one actively applies pulses at a rate
that is faster than the typical time scale of the noise. However, for
boson-mediated gates, current dynamical decoupling schemes require executing
the pulses only when the boson and the quantum systems are disentangled. This
restriction implies an increase of the gate time by a factor of $\sqrt{N}$,
with $N$ being the number of pulses applied. Here we propose and realize a
method that enables dynamical decoupling in a boson mediated system where the
pulses can be applied while spin-boson entanglement persists, resulting in an
increase in time that is at most a factor of $\frac{\pi}{2}$, independently of
the number of pulses applied. We experimentally demonstrate the robustness of
our fast dynamically decoupled entangling gate to $\sigma_z$ noise with ions in
a Paul trap.