From counterportation to local wormholes

Abstract

We propose an experimental realisation of the protocol for the counterfactual disembodied transport of an unknown qubit---or what we call counterportation---where sender and receiver, remarkably, exchange no particles. We employ cavity quantum electrodynamics, estimating resources for beating the classical fidelity limit---except, unlike teleportation, no pre-shared entanglement nor classical communication are required. Our approach is multiple orders of magnitude more efficient in terms of physical resources than previously proposed implementation, paving the way for a demonstration using existing imperfect devices. Surprisingly, while such communication is intuitively explained in terms of ``interaction-free'' measurement and the Zeno effect, we show that neither is necessary, with far-reaching implications in support of an underlying physical reality. We go on to characterise an explanatory framework for counterportation starting from constructor theory: local wormholes. Conversely, a counterportation experiment demonstrating the traversability of space, by means of what is essentially a 2-qubit exchange-free quantum computer, can point to the existence in the lab of such traversable wormholes.

The laws of physics do not prohibit counterfactual communication

“…Vaidman associates these non-zero weak values with a weak trace, claiming a quantum particle has been wherever there is this weak trace. While we do not unreservedly advocate this point of view (which has been extensively analysed [17][18][19][20] ), we still engage with it here within the frame of weak measurement, as it has been used to challenge the counterfactuality of counterfactual communication protocols 8,9,21 .…”

“…refs. 19,[26][27][28] ). Likewise, Aharonov-Vaidman's modification can be incorporated straightforwardly in our present setup.…”

“…In summary, we have shown both theoretically and experimentally that, given post-selection, sending a message without exchanging any physical particles is allowed by the laws of physics. What carries this information, however, remains a hot topic of research 19,29,30 . 11 , of which we show one cycle, cannot be said to be counterfactual from a consistent histories viewpoint.…”

Comment on ‘From counterportation to local wormholes’

“…However, Aharonov and Vaidman [11] have found a way to modify these proposals to make them indeed counterfactual. In a recent paper Salih proposed a very nice practical implementation of his original idea, see figure 2(c) of [12], describing in the text the required modification [11]. The current article corrects the analysis of Salih's simplified protocol described in figure 1 (see also figure 1 of [12]).…”

“…In a recent paper Salih proposed a very nice practical implementation of his original idea, see figure 2(c) of [12], describing in the text the required modification [11]. The current article corrects the analysis of Salih's simplified protocol described in figure 1 (see also figure 1 of [12]). We argue that the protocol presented in this figure is not counterfactual.…”