Emergence of classical objectivity of quantum Darwinism in a photonic quantum simulator

Abstract

Quantum-to-classical transition is a fundamental open question in physics frontier. Quantum decoherence theory points out that the inevitable interaction with environment is a sink carrying away quantum coherence, which is responsible for the suppression of quantum superposition in open quantum system. Recently, quantum Darwinism theory further extends the role of environment, serving as communication channel, to explain the classical objectivity emerging in quantum measurement process. Here, we used a six-photon quantum simulator to investigate classical and quantum information proliferation in quantum Darwinism process. In the simulation, many environmental photons are scattered from an observed quantum system and they are collected and used to infer the system's state. We observed redundancy of system's classical information and suppression of quantum correlation in the fragments of environmental photons. Our results experimentally show that the classical objectivity of quantum system can be established through quantum Darwinism mechanism.

Collisional unfolding of quantum Darwinism

“…Despite the fact that the topic has been the focus of much attention recently [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23], including some seminal experimental investigations [24][25][26][27][28], the phenomenology of the process through which quantum Darwinism emerges is still only partially clear or characterized. A full understanding would indeed go together with a complete grasping of decoherence, which is very much a manifestation of the physical mechanism responsible for quantum Darwinism.…”

Roads to objectivity: Quantum Darwinism, Spectrum Broadcast Structures, and Strong quantum Darwinism – a review

“…Quantum Darwinism literature is quite numerous and this is just a small sample (for the most recent research see e. g. [17]). Recently there appeared also experiments aimed at observing (3) [18][19][20], which I discuss separately in Section VIII.…”

Quantum Darwinism in a Composite System: Objectivity versus Classicality

“…In addition, while not necessary for decoherence, system-environment entanglement is required for objectivity as defined by quantum Darwinism [24]. Experimental tests of this framework in platforms consisting of photonic systems [25][26][27] and nitrogen-vacancy centers [28] have recently been reported.…”