# Suppression of leakage for a charge quadrupole qubit in triangular geometry

## TL;DR

This paper proposes a triangular geometry for charge quadrupole qubits to significantly reduce leakage, achieving up to five orders of magnitude suppression and enhancing control fidelity with composite pulses.

## Contribution

Introducing a triangular dot arrangement to suppress leakage in charge quadrupole qubits, a novel geometric approach that improves qubit fidelity.

## Key findings

- Leakage reduced by five orders of magnitude in triangular geometry
- Enhanced control fidelity with composite pulses
- Amplified tunnel coupling between outer dots

## Abstract

We present a simple yet effective strategy to suppress the leakage in the charge quadrupole qubit system by having the dots in a triangle as opposed to the linear geometry originally conceived. We find that the tunnel coupling between the two outmost dots are amplified in triangular triple dots, which consequently reduces leakage by separating the leaked state and qubit states. We have found that the leakage can be suppressed by as much as five orders of magnitude when the dots form an equilateral triangle, with further improvement of control fidelities possible if composite pulses are applied.