Zhu Zitian, Salice Kiera, Touil Akram, Bao Zehang, Song Zixuan, Zhang Pengfei, Li Hekang, Wang Zhen, Song Chao, Guo Qiujiang, Wang H, Mondaini Rubem
School of Physics, ZJU-Hangzhou Global Scientific and Technological Innovation Center, and Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, Zhejiang University, Hangzhou, China.
Department of Physics, University of Houston, Houston, TX 77204, USA.
Sci Adv. 2025 Aug;11(31):eadx6857. doi: 10.1126/sciadv.adx6857. Epub 2025 Aug 1.
The transition from quantum to classical behavior is a central question in modern physics. How can we rationalize everyday classical observations from an inherently quantum world? Quantum Darwinism offers a compelling framework to explain this by proposing that the environment redundantly encodes information about a quantum system, leading to the objective reality. Here, by leveraging cutting-edge superconducting quantum circuits, we observe the highly structured branching quantum states that support classicality and the saturation of quantum mutual information, establishing a robust verification of quantum Darwinism and the underlying geometric structure of quantum states. Additionally, we propose a particular class of observables that can be used as a computationally and experimentally inexpensive quantifier to probe quantum-to-classical transitions. Our investigation delves into how the quantum effects are inaccessible to observers, allowing only classical properties to be detected. It experimentally demonstrates the physical framework through which everyday classical observations emerge from underlying quantum principles and paves the way to settling the measurement problem.
从量子行为到经典行为的转变是现代物理学中的一个核心问题。我们如何能从一个本质上是量子的世界来合理解释日常的经典观测现象呢？量子达尔文主义提供了一个令人信服的框架来解释这一问题，它提出环境对量子系统的信息进行冗余编码，从而导致客观现实。在此，通过利用前沿的超导量子电路，我们观测到了支持经典性的高度结构化分支量子态以及量子互信息的饱和，从而对量子达尔文主义和量子态的底层几何结构进行了有力验证。此外，我们提出了一类特定的可观测量，它们可用作一种计算和实验成本低廉的量化器，以探测从量子到经典的转变。我们的研究深入探讨了观测者如何无法触及量子效应，从而只能检测到经典属性。它通过实验证明了日常经典观测如何从底层量子原理中产生的物理框架，并为解决测量问题铺平了道路。
