Information Transport Achieves Scale-Resolved Entanglement in Open Fermion Chains

Why It Matters

The work provides a scalable, experimentally viable method to probe transport‑induced entanglement, a key resource for quantum technologies operating out of equilibrium.

Key Takeaways

• Information currents shielded in particle‑hole symmetric chains.
• Impurities break shielding, enabling long‑range entanglement.
• Noise lattice links measurable fluctuations to information flow.
• Fermionic negativity quantifies transport‑induced entanglement.
• Method avoids full state tomography, suitable for quantum‑dot platforms.

Pulse Analysis

Open quantum systems driven far from equilibrium have long challenged theorists because entanglement, a non‑local quantity, resists simple hydrodynamic description. The new "information lattice" approach reframes the problem by treating information as a locally conserved current, allowing Lindblad master equations to be solved analytically for large Gaussian fermion chains. This shift not only simplifies calculations but also aligns the theory with quantities that experimentalists can directly measure, such as particle‑number fluctuations and current noise, bridging a critical gap between abstract quantum information theory and real‑world devices.

A striking result of the study is the discovery of "information shielding" in clean, particle‑hole symmetric chains, where information currents remain confined and do not propagate through the lattice. Introducing impurities or breaking particle‑hole symmetry lifts this protection, producing measurable information currents that correlate tightly with fermionic negativity—a robust entanglement metric for mixed states. By constructing a complementary "noise lattice" from onsite occupation variances and covariances, the authors demonstrate that these information currents can be extracted from standard transport measurements, eliminating the need for full quantum‑state tomography.

The practical implications are significant for emerging quantum technologies. Quantum‑dot arrays and ultracold fermionic atom setups can now probe transport‑induced entanglement using existing noise spectroscopy tools, accelerating the validation of quantum devices that rely on non‑equilibrium resources. Moreover, the framework sets the stage for extending the analysis to interacting systems and more complex driving protocols, promising deeper insight into how information flow underpins the performance of future quantum processors and sensors.