Efficient composite pulse sequences for arbitrarily accurate z-axis rotation gates

TL;DR

This paper introduces new composite pulse sequences for z-axis rotation gates in quantum computing, achieving higher fidelity and error suppression with shorter sequences, scalable to arbitrary accuracy.

Contribution

The authors develop analytic formulas for constructing composite pulses that suppress systematic errors to any order with linear sequence length scaling.

Findings

Higher gate fidelity compared to existing methods

Shorter sequence times for robust z-rotations

Sequences scalable to arbitrary accuracy

Abstract

We propose various composite $\pi$-pulse sequences for implementing robust z-axis rotation gates widely used in quantum information processing (QIP) scenarios, and discuss their error tolerance of the pulse strength error (PSE) and off-resonance error (ORE), i.e., two typical systematic errors in NMR systems. Compared to existing composite gates, our designed composite pulses exhibit higher gate fidelity and shorter sequence time cost. Furthermore, such short pulse sequences are generalized by simple analytic formulas which can suppress these errors to any desired order simultaneously with linear length scaling, indicating an efficient construction of them with arbitrary accuracy.