Highly photon loss tolerant quantum computing using hybrid qubits

TL;DR

This paper presents a hybrid qubit scheme for topological quantum computing that significantly improves photon loss tolerance up to 5.7×10⁻³ by using postselection and advanced entangling operations, while maintaining resource efficiency.

Contribution

It introduces a novel hybrid qubit approach with enhanced photon loss threshold using postselection and multi-Bell-state measurements, outperforming previous optical schemes.

Findings

Photon loss threshold improved to 5.7×10⁻³

Resource consumption increased by an order of magnitude

Scheme remains resource-efficient compared to other optical methods

Abstract

We investigate a scheme for topological quantum computing using optical hybrid qubits and make an extensive comparison with previous all-optical schemes. We show that the photon loss threshold reported by Omkar {\it et al}. [Phys. Rev. Lett. 125, 060501 (2020)] can be improved further by employing postselection and multi-Bell-state-measurement based entangling operation to create a special cluster state, known as Raussendorf lattice for topological quantum computation. In particular, the photon loss threshold is enhanced up to $5.7\times10^{-3}$, which is the highest reported value given a reasonable error model. This improvement is obtained at the price of consuming more resources by an order of magnitude, compared to the scheme in the aforementioned reference. Neverthless, this scheme remains resource-efficient compared to other known optical schemes for fault-tolerant quantum computation.