Visibility of noisy quantum dot-based measurements of Majorana qubits

TL;DR

This paper investigates how noise affects the measurement visibility of Majorana qubits using quantum dots, finding that high-fidelity measurements are feasible even with realistic noise levels.

Contribution

It provides a detailed analysis of noise effects on quantum dot-based Majorana qubit measurements, highlighting optimal measurement conditions and robustness against noise.

Findings

On- or near-resonance measurements improve visibility

Noise coupling does not significantly limit measurement fidelity

Quantitative predictions for noise effects on charge and capacitance

Abstract

Measurement schemes of Majorana zero modes (MZMs) based on quantum dots (QDs) are of current interest as they provide a scalable platform for topological quantum computation. In a coupled qubit-QD setup we calculate the dependence of the charge of the QD and its differential capacitance on experimentally tunable parameters for both 2-MZM and 4-MZM measurements. We quantify the effect of noise on the measurement visibility by considering $1/f$ noise in detuning, tunneling amplitudes or phase. We find that on- or close-to-resonance measurements are generally preferable and predict, using conservative noise estimates, that noise coupling to the QDs is not a limitation to high-fidelity measurements of topological qubits.