Robust interface between flying and topological qubits

TL;DR

This paper proposes a microwave photonic quantum bus that enables strong, robust coupling between topological and conventional qubits, overcoming energy mismatch issues and facilitating quantum information exchange.

Contribution

It introduces a novel scheme using external driving fields to achieve robust coupling between different energy scale qubits via a microwave photonic bus.

Findings

Energy splitting of topological qubits remains robust against local perturbations.

The scheme enables a robust interface between flying and topological qubits.

The quantum bus can generate multipartite entangled states.

Abstract

Hybrid architectures, consisting of conventional and topological qubits, have recently attracted much attention due to their capability in consolidating the robustness of topological qubits and the universality of conventional qubits. However, these two kinds of qubits are normally constructed in significantly different energy scales, and thus this energy mismatch is a major obstacle for their coupling that supports the exchange of quantum information between them. Here, we propose a microwave photonic quantum bus for a direct strong coupling between the topological and conventional qubits, in which the energy mismatch is compensated by the external driving field via the fractional ac Josephson effect. In the framework of tight-binding simulation and perturbation theory, we show that the energy splitting of the topological qubits in a finite length nanowire is still robust against local perturbations, which is ensured not only by topology, but also by the particle-hole symmetry. Therefore, the present scheme realizes a robust interface between the flying and topological qubits. Finally, we demonstrate that this quantum bus can also be used to generate multipartitie entangled states with the topological qubits.