Quantum Darwinism in hazy environments

H. T. Quan, Michael P. Zwolak, Wojciech Hubert Zurek

Wojciech Hubert Zurek

Michael P. Zwolak, H. T. Quan, Wojciech Hubert Zurek

Quantum Darwinism recognizes that we-the observers-acquire our information about the "systems of interest" indirectly from their imprints on the environment. Here, we show that information about a system can be acquired from a mixed-state, or hazy, environment, but the storage capacity of an environment fragment is suppressed by its initial entropy. In the case of good decoherence, the mutual information between the system and the fragment is given solely by the fragment's entropy increase. For fairly mixed environments, this means a reduction by a factor 1-h, where h is the haziness of the environment, i.e., the initial entropy of an environment qubit. Thus, even such hazy environments eventually reveal the state of the system, although now the intercepted environment fragment must be larger by approximately (1-h)(-1) to gain the same information about the system.

Steve Campbell, Barış Çakmak, Özgür Esat Müstecaplıoğlu +2 more

We examine the emergence of objectivity via quantum Darwinism through the use of a collision model, i.e., where the dynamics is modeled through sequences of unitary interactions between the system and the individual constituents of the environment, termed ``ancillas.'' By exploiting versatility of this framework, we show that one can transition from a ``Darwinistic'' to an ``encoding'' environment by simply tuning their interaction. Furthermore, we establish that in order for a setting to exhibit quantum Darwinism we require a mutual decoherence to occur between the system and environmental ancillas, thus showing that system decoherence alone is not sufficient. Finally, we demonstrate that the observation of quantum Darwinism is sensitive to a nonuniform system-environment interaction.

Zeeya Merali

Nadia Milazzo, Salvatore Lorenzo, Mauro Paternostro +1 more

Quantum Darwinism attempts to explain the emergence of objective reality of the state of a quantum system in terms of redundant information about the system acquired by independent noninteracting fragments of the environment. The consideration of interacting environmental elements gives rise to a rich phenomenology, including the occurrence of non-Markovian features, whose effects on objectification in the manner of quantum Darwinism needs to be fully understood. We study a model of local interaction between a simple quantum system and a multimode environment that allows for a clear investigation of the interplay between information trapping and propagation in the environment and the emergence of quantum Darwinism. We provide strong evidence of the correlation between non-Markovianity and quantum Darwinism in such a model, thus providing strong evidence of a potential link between such fundamental phenomena.