# Resource-efficient and fault-tolerant topological quantum computation with hybrid entanglement of light

## TL;DR

This paper introduces a linear-optical scheme for topological quantum computation that uses hybrid light entanglement, significantly improving photon-loss tolerance and reducing resource overheads compared to previous methods.

## Contribution

It presents a novel all-linear-optical approach utilizing hybrid photonic qubits for fault-tolerant quantum computing with enhanced loss thresholds and lower resource requirements.

## Key findings

- Photon-loss threshold of ~3.3×10⁻³, higher than existing optical schemes.
- Resource overhead for logical error rate of 10⁻⁶ is ~8.5×10⁵.
- Resource overhead for logical error rate of 10⁻¹⁵ is ~1.7×10⁷.

## Abstract

We propose an all-linear-optical scheme to ballistically generate a cluster state for measurement-based topological fault-tolerant quantum computation using hybrid photonic qubits entangled in a continuous-discrete domain. Availability of near-deterministic Bell-state measurements on hybrid qubits is exploited for the purpose. In the presence of photon losses, we show that our scheme leads to a significant enhancement in both tolerable photon-loss rate and resource overheads. More specifically, we report a photon-loss threshold of $\sim3.3\times 10^{-3}$, which is higher than those of known optical schemes under a reasonable error model. Furthermore, resource overheads to achieve logical error rate of $10^{-6} (10^{-15})$ is estimated to be $\sim8.5\times10^{5} (1.7\times10^{7})$ which is significantly less by multiple orders of magnitude compared to other reported values in the literature.