Error sources in heralded quantum Zeno gates

TL;DR

This paper analyzes the error sources in heralded quantum Zeno gates for photonic qubits, revealing new potential errors beyond previous models by solving Schrödinger's equation for photon-atom systems.

Contribution

It introduces a detailed quantum dynamical model to identify additional error sources in heralded quantum Zeno gates beyond earlier simplified assumptions.

Findings

Identifies new error sources not captured by previous models

Shows the impact of these errors on gate fidelity

Provides a more comprehensive understanding of gate performance

Abstract

Quantum logic gates for photonic qubits can be implemented using the quantum Zeno effect based on strong two-photon absorption. The fidelity of quantum Zeno gates of this kind may be substantially reduced by photon loss. Heralding on those outcomes in which both of the logical qubits emerge from the Zeno gate can increase the fidelity at the expense of a limited success rate (P.M. Leung et al., Phys. Rev. A 74, 062325 (2006)). We analyze the performance of heralded quantum Zeno gates by solving Schrodinger's equation for a system of photons coupled to three-level atoms. This approach identifies several potential error sources that are not described by earlier models that assumed a fixed rate of single-photon loss and two-photon absorption.