Coherent Information Phase Transition in a Noisy Quantum Circuit

Fuente: arXiv
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Main Authors: Qian, Dongheng, Wang, Jing
Format: Preprint
Published: 2024
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author Qian, Dongheng
Wang, Jing
author_facet Qian, Dongheng
Wang, Jing
contents 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 post-selection 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.
format Preprint
id arxiv_https___arxiv_org_abs_2408_16267
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Coherent Information Phase Transition in a Noisy Quantum Circuit
Qian, Dongheng
Wang, Jing
Quantum Physics
Disordered Systems and Neural Networks
Statistical Mechanics
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 post-selection 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.
title Coherent Information Phase Transition in a Noisy Quantum Circuit
topic Quantum Physics
Disordered Systems and Neural Networks
Statistical Mechanics
url https://arxiv.org/abs/2408.16267