Designing arbitrary single-axis rotations robust against perpendicular time-dependent noise

TL;DR

This paper introduces a new method for designing bounded, continuous control pulses that enable arbitrary single-axis rotations in quantum systems, effectively shielding against low-frequency perpendicular noise and outperforming traditional dynamical decoupling sequences.

Contribution

The work presents a novel protocol for creating bounded, continuous control fields for arbitrary rotations that are robust against low-frequency perpendicular noise in quantum systems.

Findings

Control pulses effectively shield against classical 1/f noise.

Pulses outperform ideal dynamical decoupling sequences in robustness.

Applicable to systems with constrained control, like singlet-triplet spin qubits.

Abstract

Low-frequency time-dependent noise is one of the main obstacles on the road towards a fully scalable quantum computer. The majority of solid-state qubit platforms, from superconducting circuits to spins in semiconductors, are greatly affected by $1/f$ noise. Among the different control techniques used to counteract noise effects on the system, dynamical decoupling sequences are one of the most effective. However, most dynamical decoupling sequences require unbounded and instantaneous pulses, which are unphysical and can only implement identity operations. Among methods that do restrict to bounded control fields, there remains a need for protocols that implement arbitrary gates with lab-ready control fields. In this work, we introduce a protocol to design bounded and continuous control fields that implement arbitrary single-axis rotations while shielding the system from low-frequency time-dependent noise perpendicular to the control axis. We show the versatility of our method by presenting a set of non-negative-only control pulses that are immediately applicable to quantum systems with constrained control, such as singlet-triplet spin qubits. Finally, we demonstrate the robustness of our control pulses against classical $1/f$ noise and noise modeled with a random quantum bath, showing that our pulses can even outperform ideal dynamical decoupling sequences.