Trapped-ion entangling gates robust against qubit frequency errors

Jake Lishman,Florian Mintert

doi:10.1103/physrevresearch.2.033117

Abstract

Entangling operations are a necessary tool for large-scale quantum information processing, but experimental imperfections can prevent current schemes from reaching sufficient fidelities as the number of qubits is increased. Here it is shown numerically how multi-toned generalizations of standard trapped-ion entangling gates can simultaneously be made robust against noise and mis-sets of the frequencies of the individual qubits. This relaxes the degree of homogeneity required in the trapping field, making physically larger systems more practical.

Highlights

A major goal in quantum information processing is to reach the level of a fast, highly scalable universal quantum computer
Single-qubit gates have been achieved in ion traps at fidelities over 99% for over a decade [12], with more recent works taking the average gate infidelity to 10−6 [13]
The current state-of-the-art fidelities for two-qubit gates are performed in ion traps, achieving infidelities of less than 10−3 with laser-induced gates [14,15] and 3 × 10−3 with microwave-controlled schemes [16], requiring very low tolerances in homogeneity and stability of control and trapping fields, with scalability remaining a large problem

Summary

Introduction

A major goal in quantum information processing is to reach the level of a fast, highly scalable universal quantum computer. To reach universality for a constant number of qubits, only a small set of operations is absolutely required: a small number of single-qubit operations, and a single two-qubit entangling operation Throughout their development, quantum gate implementations have always contended with noise reduction, with varying estimates placing the maximum allowable probability of failure per gate at between 10−2 and 10−4 [11]. Proposals to enlarge ion-trap computers typically focus on producing modular systems, either on physically shuttling ions [17] or introducing probabilistic photonic interconnects between separated traps [18]

Methods

Results

Conclusion