Experimental superposition of a quantum evolution with its time reverse - CNRS - Centre national de la recherche scientifique
Journal Articles Physical Review Research Year : 2024

Experimental superposition of a quantum evolution with its time reverse

Abstract

In the macroscopic world, time is intrinsically asymmetric, flowing in a specific direction, from past to future. However, the same is not necessarily true for quantum systems, as some quantum processes produce valid quantum evolutions under time reversal. Supposing that such processes can be probed in both time directions, we can also consider quantum processes probed in a coherent superposition of forwards and backwards time directions. This yields a broader class of quantum processes than the ones considered so far in the literature, including those with indefinite causal order. In this work, we demonstrate for the first time an operation belonging to this new class: the quantum time flip. Using a photonic realisation of this operation, we apply it to a game formulated as a discrimination task between two sets of operators. This game not only serves as a witness of an indefinite time direction, but also allows for a computational advantage over strategies using a fixed time direction, and even those with an indefinite causal order.

Dates and versions

hal-03858633 , version 1 (17-11-2022)

Identifiers

Cite

Teodor Strömberg, Peter Schiansky, Marco Túlio Quintino, Michael Antesberger, Lee Rozema, et al.. Experimental superposition of a quantum evolution with its time reverse. Physical Review Research, 2024, 6 (2), pp.023071. ⟨10.1103/PhysRevResearch.6.023071⟩. ⟨hal-03858633⟩
294 View
0 Download

Altmetric

Share

More