Device-independent test of a delayed choice experiment

Abstract

Wave-particle duality has long been considered a fundamental signature of the non-classical behavior of quantum phenomena, specially in a delayed choice experiment (DCE), where the experimental setup revealing either the particle or wave nature of the system is decided after the system has entered the apparatus. However, as counter-intuitive as it might seem, usual DCEs do have a simple causal explanation. Here, we take a different route and under a natural assumption about the dimensionality of the system under test, we present an experimental proof of the non-classicality of a DCE based on the violation of a dimension witness inequality. Our conclusion is reached in a device-independent and loophole-free manner, that is, based solely on the observed data and without the need on any assumptions about the measurement apparatus.

Experimental violation of n-locality in a star quantum network[1]

“…A new approach has been introduced in the last few years to properly analyze these networks, which leverages on the theory of causal inference 38 . Indeed, the causal modeling approach 39 has become a customary and powerful tool to represent classical and quantum networks 27,[40][41][42][43] . In this framework, directed acyclic graphs (DAGs) provide both a graphical and a mathematical way to visualize causal structures (see Fig.…”

Experimental violation of n-locality in a star quantum network

“…A new approach has been introduced in the last few years to properly analyze these networks, which leverages on the theory of causal inference 38 . Indeed, the causal modeling approach 39 has become a customary and powerful tool to represent classical and quantum networks 27,[40][41][42][43] . In this framework, directed acyclic graphs (DAGs) provide both a graphical and a mathematical way to visualize causal structures (see Fig.…”

Compatibility of causal hidden-variable theories with a delayed-choice experiment

“…H.-L. Huang and Y.-H. Luo contributed equally to this work. During the final stages of manuscript preparation, we became aware of a similar work by Polino et al [29], which was carried out simultaneously and independently.…”