Quantum dealing of poker cards

How to play poker on the phone if you do not trust your opponent or the card dealer? Find out how, by using discorrelated quantum states. On the cover of Advanced Quantum Technologies, May 2021.

We present the first experimental evidence of a joint statistical property of multiphoton quantum states, called discorrelation. It can appear between two or more parties and, differently from typical classical and quantum correlations, it is characterized by an “exclusive” photon-number anti-correlation. Measurements of the photon number by different parties are random but never return the same results.
Unlike quantum key distribution, where common random keys need to be shared, discorrelation can be used to distribute unique random numbers among parties, for example to implement mental poker schemes without the need for a trusted card dealer between distant players.
We have generated discorrelated states by using our recently developed method of delocalized single-photon addition between two distinct coherent laser pulses.