Causal Modeling the Delayed-Choice Experiment

Abstract

Wave-particle duality has become one of the flagships of quantum mechanics. This counterintuitive concept is highlighted in a delayed-choice experiment, where the experimental setup that reveals either the particle or wave nature of a quantum system is decided after the system has entered the apparatus. Here we consider delayed-choice experiments from the perspective of device-independent causal models and show their equivalence to a prepare-and-measure scenario. Within this framework, we consider Wheeler's original proposal and its variant using a quantum control and show that a simple classical causal model is capable of reproducing the quantum mechanical predictions. Nonetheless, among other results, we show that, in a slight variant of Wheeler's gedanken experiment, a photon in an interferometer can indeed generate statistics incompatible with any nonretrocausal hidden variable model, whose dimensionality is the same as that of the quantum system it is supposed to mimic. Our proposal tolerates arbitrary losses and inefficiencies, making it specially suited to loophole-free experimental implementations.

Device-independent test of a delayed choice experiment

“…A delayed choice experiment as a prepare and measure scenario -As recently noted in [21], a DCE ( Fig. 2b) can be seen as a particular instance of a PAM scenario ( Fig.…”

“…In spite of the fact that Wheeler's and quantum DCEs are of classical nature from the DI perspective, it has also been shown that minor modifications of the original proposals can rule out, with a DI protocol, HV models as a possible explanation [21]. In this new framework, apart from the assumption of non-retrocausality, the HV is also assumed to have the same dimension as the quantum system it is supposed to mimic.…”

Realization of a causal-modeled delayed-choice experiment using single photons

“…Recently, a new proposal [19] based on the causal model demonstrated that a two-dimensional classical hidden variable model could explain the outcomes of WDCE and QDCE. Herein, the delayed-choice experiments could be considered from the perspective of deviceindependent causal models in a prepare-and-measure scenario.…”

“…In Ref. [19], Chaves et al proposed that the delayed-choice experiment can be regarded as a DI prepare-and-measure (PAM) scenario ( Fig. 1(b)).…”

Encrypted quantum correlations: delayed choice of quantum statistics and other applications

“…Again, the quantum properties are not determined until the full system, comprising both photons in an entangled state, has been measured. Since their early conception [7,3], "delayed-choice" techniques have been extended to scenarios beyond the wave-particle duality [8,4] and continue to attract the interest of researchers to this date [9].…”