Export citation

Export citation

Choose format for download:

Download Citation
  • Letter

Coherent information phase transition in a noisy quantum circuit

Dongheng Qian1,2 and Jing Wang1,2,3,4,*

  • *Contact author: wjingphys@fudan.edu.cn

Phys. Rev. B 112, L180301 – Published 6 November, 2025

DOI: https://doi.org/10.1103/b8tq-z48t

Abstract

Coherent information quantifies the transmittable quantum information through a channel and is directly linked to the channel's quantum capacity. In a monitored quantum circuit, regarded as a quantum channel, extensive and positive coherent information is sustained at low measurement rates, protected by the scrambling dynamics. However, noise suppresses coherent information, driving it to zero or negative values. Here, we show that incorporating quantum-enhanced operations facilitates reliable quantum information transmission even in the presence of noise, as evidenced by a phase transition in coherent information from a recoverable phase with positive values to an irrecoverable phase with negative values. We provide both analytical understanding and numerical evidence demonstrating this transition, which is modulated by the relative frequencies of noise and quantum-enhanced operations. Additionally, we propose a resource-efficient protocol to characterize this phase transition in experiments, effectively avoiding postselection by utilizing every run of the quantum circuit. This approach bridges the gap between theoretical insights and practical implementation, making the phase transition feasible to demonstrate on realistic noisy intermediate-scale quantum devices.

Physics Subject Headings (PhySH)

Authorization Required

We need you to provide your credentials before accessing this content.

Supplemental Material (Subscription Required)

References (Subscription Required)

Outline

Information

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation