Research published this month in the Proceedings of the National Academy of Sciences (PNAS) introduced a current quantum phenomenon which the authors called the "quantum pigeonhole principle." Prior to this breakthrough,the pigeonhole principle was a basic tenet of conventional wisdom. It states that whether you put three pigeons in two pigeonholes then at least two of the pigeons must end up in the same gap. It is an obvious yet fundamental principle of nature as it captures the very essence of counting. The research, conducted by members of Chapman University's Institute for Quantum Studies (IQS), or violates this principle. The study demonstrates how to put an arbitrarily large number of particles in two boxes without any two particles ending up in the same box.
Source: phys.org