On the Origin of Classicality: Quantum Darwinism in Superconducting Circuits

We outline a comprehensive exploration into the foundational ideas of Quantum Darwinism, including

the emergence of branching structures and classicality through informational theoretic quantities such as

mutual, quantum discord, and Holevo information. We detail experimental investigation of these ideas

using superconducting quantum circuits providing a robust verification of this theory. Additionally, we

propose a special class of observables that can be used as a separate quantifier for classicality by showing

a one-to-one correspondence with the classical plateau of the mutual information. This quantity, which

we provide both mathematical proof and experimental verification, proves a computationally and experi-

mentally inexpensive way to observe the emergence of classicality.