# Quantum state revival via coherent energy redistribution

## TL;DR

This paper introduces a method to recover and enhance quantum states corrupted by noise using coherent energy redistribution.

## Contribution

The novel contribution is a technique to revive and improve entangled quantum states through coherent energy redistribution.

## Key findings

- An order of magnitude increase in the coincidence-to-accidental ratio for time-bin entangled photon pairs was achieved.
- Quantum interference visibility and fidelity were restored in qubits corrupted by noise using quantum state tomography.

## Abstract

Processing and detecting quantum states with high fidelity are essential for enabling quantum advantages across many applications. However, these states are known to be fragile because of their sensitivity to losses, their inability to be amplified, and their susceptibility to decoherence. This makes them far more vulnerable to noise than classical signals, limiting their out-of-lab deployment. We demonstrate quantum coherent energy redistribution, which not only recovers entangled states buried in noise but also improves their properties, moving toward noise-robust architectures with better deployability. Using standard telecommunications infrastructure, we show an order of magnitude increase in the coincidence-to-accidental ratio for time-bin entangled photon pairs. Furthermore, we demonstrate the revival of lost entanglement by recovering quantum interference visibility and fidelity from quantum state tomography measurements of qubits corrupted by noise.

The quantum properties of photons lost due to noise are recovered by coherently redistributing their correlations.