Transverse multi-mode effects on the performance of photon-photon gates

TL;DR

This paper investigates how transverse multi-mode effects impact the performance of photon-photon quantum gates, revealing significant constraints and proposing potential solutions like separating photons transversely.

Contribution

It extends the study of multi-mode effects from longitudinal to transverse degrees of freedom in quantum photonic gates, highlighting their importance.

Findings

Transverse multi-mode effects significantly affect gate fidelity.

Separating photons transversely can mitigate these effects.

Transverse effects were previously underexplored in this context.

Abstract

The multi-mode character of quantum fields imposes constraints on the implementation of high-fidelity quantum gates between individual photons. So far this has only been studied for the longitudinal degree of freedom. Here we show that effects due to the transverse degrees of freedom significantly affect quantum gate performance. We also discuss potential solutions, in particular separating the two photons in the transverse direction.