University of Campinas–UNICAMP, Brazil, rdbaldi@ifi.unicamp.br
(joint work with Marcelo Terra Cunha, Rafael Wagner, Cristhiano Duarte, and Bárbara Amaral)
Quantum contextuality is one of the fundamental features responsible for distinguishing the quantum and the classical descriptions of nature. On the other hand, the so-called ‘Classical limits’ research area attempts to understand how our classical everyday experience may arise from the quantum realm. For instance, under this kind of program, we can understand loss of coherence (so-called Decoherence) and emergence of ‘objectivity’ (quantum Darwinism). However, one important question remains: if contextuality is such an important nonclassical feature, how classical limits explain its disappearance to allow for a reconciliation?
In this talk, we discuss classical limits of quantum theory in the perspective of (non)contextuality. In particular, we analyze how noncontextuality can emerge in a suitable setting resembling the collisional approach to open systems [1], discussing its relation to other kinds of emergence of classicality in a similar setting. Moreover, we also show that if a Darwinism process is successful enough, noncontextuality will emerge: independent observers will have a noncontextual explanation to what they collectively see [2]. In other words, if interaction of a system and portions of its environment leads to objectivity of observables and objectivity of outcomes, as defined by Brandão, Piani and Horodecki [3], noncontextuality emerges.
[1] R.D.Baldijão, M. Terra Cunha, Classical limits and contextuality in a scenario with multiple observers, Phys. Rev. A,102, 052226
[2] R.D.Baldijão, R. Wagner, C. Duarte, B. Amaral, M. Terra Cunha, Emergence of noncontextuality under quantum Darwinism, in prep.; will be available on arXiv by the time of the QCQMB 2021 Workshop. The current version of the draft can be sent upon request.
[3] F.L.S.Brandão, M. Piani., P. Horodecki, Generic emergence of classical features under quantum Darwinism, nature physics,6, Article number: 7908