Sensitivity of entangled photon holes to loss and amplification

TL;DR

Entangled photon holes exhibit robustness against photon loss and can be amplified, making them promising for quantum communication systems with limited range due to loss.

Contribution

This paper demonstrates the relative insensitivity of energy-time entangled photon holes to photon loss and their potential for amplification, highlighting their advantages over traditional entangled photons.

Findings

Photon holes are insensitive to atomic absorption loss.

High-intensity photon holes can be amplified.

Photon loss effects cannot always be modeled as beam splitter losses.

Abstract

Energy-time entangled photon holes are shown to be relatively insensitive to photon loss due to absorption by atoms whose coherence times are longer than the time delays typically employed in nonlocal interferometry (a fraction of a nanosecond). Roughly speaking, the excited atoms do not retain any significant "which-path" information regarding the time at which a photon was absorbed. High-intensity entangled photon holes can also be amplified under similar conditions. Decoherence does occur from losses at beam splitters, and these results show that photon loss cannot always be adequately modeled using a sequence of beam splitters. These properties of entangled photon holes may be useful in quantum communications systems where the range of the system is limited by photon loss.