Experimental realization of an entanglement filter through the environmental selection

TL;DR

This experiment demonstrates how environmental selection can be used as a mechanism to create and filter entangled states, showcasing a practical application of quantum Darwinism principles in quantum information processing.

Contribution

The paper presents the first experimental realization of an entanglement filter driven by environmental selection, linking quantum Darwinism to entanglement generation.

Findings

Achieved an entanglement fidelity of 94.7% in the generated state

The entanglement produced is robust against variations in initial states and environmental parameters

Validated the concept of environmental selection as a practical tool for quantum state engineering

Abstract

We report an experiment that uses the environmental selection, a key concept in the recent theory of quantum Darwinism, as a mechanism to realize the entanglement filter, a useful quantum information device that filters out certain entangled states. In the experiment, the environment of two qubits is controlled to favor an entangled state and kill other competing components in the input state. The initial state has vanishing entanglement, but the state surviving after interaction with the environment is close to a maximally entangled state, with an entanglement fidelity of $(94.7\pm 1.9)%$ measured through the quantum state tomography. We experimentally demonstrate that the generated entanglement is robust under change of the initial state configurations and the environmental parameters.