Versatile microwave-driven trapped ion spin system for quantum information processing

TL;DR

This paper presents a microwave-driven trapped ion spin system that enables versatile quantum simulations and computations, including quantum memory and dynamic control of spin interactions, demonstrated through a quantum Fourier transform.

Contribution

It introduces a microwave-based method for controlling trapped ion spins, allowing dynamic decoupling and sign-changing of spin-spin couplings, advancing quantum simulation and computation capabilities.

Findings

Demonstrated selective spin decoupling using microwave pulses

Achieved dynamic control of spin-spin coupling strength and sign

Realized a quantum Fourier transform with three coupled spins

Abstract

Using trapped atomic ions we demonstrate a tailored and versatile effective spin-system suitable for quantum simulations and universal quantum computation. By simply applying microwave pulses, selected spins can be decoupled from the remaining system and thus can serve as a quantum memory, while simultaneously, other coupled spins perform conditional quantum dynamics. Also, microwave pulses can change the sign of spin-spin couplings, as well as their effective strength, even during the course of a quantum algorithm. Taking advantage of the simultaneous long-range coupling between three spins a coherent quantum Fourier transform -- an essential building block for many quantum algorithms -- is efficiently realized. This approach, which is based on microwave-driven trapped ions and is complementary to laser-based methods, opens a new route to overcoming technical and physical challenges in the quest for a quantum simulator and a quantum computer.