Southwest Quantum Information and Technology

Experimental demonstration of robust phase estimation near the Heisenberg limit

Presenting Author: Kenneth Rudinger, Sandia
Contributing Author(s): Shelby Kimmel (QuICS, University of Maryland), Daniel Lobser (Sandia National Laboratories), and Peter Maunz (Sandia National Laboratories)

High-fidelity gate operations are one of many requirements for full-scale quantum computation. A variety of benchmarking and tomographic protocols have been developed to aid in the characterization and improvement of these operations. In this talk, we will discuss robust phase estimation (RPE), a particular protocol that can be used to learn the phases of quantum operations to very high accuracy. Unlike many other phase estimation protocols, RPE requires no ancillae nor near-perfect state preparation or measurement. We demonstrate the first published experimental implementation of RPE on a single-qubit system (a trapped Yb\(^+\) ion), and use it to learn the phases of X and Y rotations to within \(\sim10^{-4}\) radians. This accuracy requires only 352 experimental samples per phase, and exhibits Heisenberg-like scaling. We also explore how this accuracy appears to outperform the original theoretical bounds on RPE. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04 94AL85000.

(Session 11 : Saturday from 11:30am - 12:00pm)