Rabi and Ramsey oscillations of a Majorana qubit in a quantum dot-superconductor array

TL;DR

This paper proposes a method to realize and analyze Majorana qubits in quantum dot-superconductor arrays, demonstrating Rabi and Ramsey oscillations with realistic effects, and shows larger energy gaps improve qubit performance.

Contribution

It introduces a feasible approach for constructing and reading out Majorana qubits in quantum dot setups, incorporating realistic noise effects and performance enhancements.

Findings

Larger energy gaps lead to longer dephasing times.

Majorana qubits show higher quality factors and reduced leakage.

Quantum capacitance measurement enables qubit readout.

Abstract

The Kitaev chain can be engineered within a quantum dot-superconductor array, hosting Majorana zero modes at fine-tuned sweet spots. In this work, we propose and simulate the occurrence of Rabi and Ramsey oscillations to feasibly construct a minimal Majorana qubit in the quantum dot setup. Our real-time results incorporate realistic effects, e.g., charge noise and leakage, reflecting the latest experimental progress. We demonstrate that Majorana qubits with larger energy gaps exhibit significantly enhanced performance -- longer dephasing times, higher quality factors, reduced leakage probabilities, and improved visibilities -- compared to those with smaller gaps and with conventional quantum dot-based charge qubits. We introduce a method for reading out Majorana qubits via quantum capacitance measurements. Our work paves the way for future experiments on realizing Majorana qubits in quantum dot-superconductor arrays.