This week’s Image of the week Alice and Bob face off in a deadly duel which one of them might not survive. Luckily, this is nothing as morbid as a real duel – Alice and Bob are the classic protagonists of a myriad of quantum situations, and the duel they are engaged is a duel game, as found in game theory. Alice and Bob both have a particular skill, and fire in a particular order, and based on these inputs the probability of one or other surviving a round of the duel can be found. When the situation is quantised, various quantum effects appear – one of the duelists can be revived after successful shots by their opponent for example.
Researchers from Universidade Federal Fluminense in Brazil experimentally realise the quantum duel in W F Balthazar et al 2015 J. Phys. B: At. Mol. Opt. Phys. 48 165505. Rather than guns, they use linear optical cicuits made up of laser beams to encode the ‘states’ of Alice and Bob in the properties of the electromagnetic fields used. By changing these input states (whether Alice or Bob are alive or dead, or both) at the start of the round they observe the outcome of the duel and find that their results match theoretical predictions well.
This work is licensed under a Creative Commons Attribution 3.0 Unported License
Front Image and article image: Results for the probability to Alice be dead and Bob be alive at the end of the first round of the duel as function of their respective shooting parameters, from W F Balthazar et al 2015 J. Phys. B: At. Mol. Opt. Phys. 48 165505