Single-shot energetic-based estimator for entanglement in a half-parity measurement setup

TL;DR

This paper introduces a novel energetic-based estimator for detecting entanglement between distant qubits in a half-parity measurement setup, utilizing continuous energetic fluctuations to assess entanglement in real-time.

Contribution

The work develops a single-shot, robust estimator based on energetic fluctuations that can identify entanglement at the single-trajectory level in a half-parity measurement scheme.

Findings

The energetic fluctuations correlate with the entanglement rate.

The estimator is valid at the single-trajectory level.

It remains robust despite finite detection efficiency.

Abstract

Producing and certifying entanglement between distant qubits is a highly desirable skill for quantum information technologies. Here we propose a new strategy to monitor and characterize entanglement genesis in a half parity measurement setup, that relies on the continuous readout of an energetic observable which is the half-parity observable itself. Based on a quantum-trajectory approach, we theoretically analyze the statistics of energetic fluctuations for a pair of continuously monitored qubits. We quantitatively relate these energetic fluctuations to the rate of entanglement produced between the qubits, and build an energetic-based estimator to assess the presence of entanglement in the circuit. Remarkably, this estimator is valid at the single-trajectory level and shows to be robust against finite detection efficiency. Our work paves the road towards a fundamental understanding of the stochastic energetic processes associated with entanglement genesis, and opens new perspectives for witnessing quantum correlations thanks to quantum thermodynamic quantities.