Using hybrid topological-spin qubit systems for two-qubit-spin gates

TL;DR

This paper proposes a hybrid quantum system combining spin and topological qubits, enabling entangling two-qubit gates through a combination of braiding, charge transfer, and measurement techniques.

Contribution

It introduces a novel method for implementing two-qubit gates using a hybrid system of spin and topological qubits with topologically protected operations.

Findings

Demonstrates transfer of quantum information between spin and topological qubits

Shows how to perform entangling two-qubit gates on spatially separated spin qubits

Utilizes braiding, charge transfer, and measurement for gate operations

Abstract

We investigate a hybrid quantum system involving spin qubits, based on the spins of electrons confined in quantum dots, and topological qubits, based on Majorana fermions. In such a system, gated control of the charge on the quantum dots allows transfer of quantum information between the spin and topological qubits, and the topological system can be used to facilitate transfer of spin qubits between spatially separated quantum dots and to initialize entangled spin-qubit pairs. Here, we show that the coupling to the topological system also makes it possible to perform entangling two-qubit gates on spatially separated spin qubits. The two-qubit gates are based on a combination of topologically protected braiding operations, gate-controlled charge transfer between the dots and edge Majorana modes, and measurements of the state of the topological qubits.