biostudies-literatureYong CKEngineering and Physical Sciences Research Council15953https://www.ebi.ac.uk/biostudies/studies/S-EPMC5510179biostudies-literatureUnknown8Entanglement of states is one of the most surprising and counter-intuitive consequences of quantum mechanics, with potent applications in cryptography and computing. In organic materials, one particularly significant manifestation is the spin-entangled triplet-pair state, which mediates the spin-conserving fission of one spin-0 singlet exciton into two spin-1 triplet excitons. Despite long theoretical and experimental exploration, the nature of the triplet-pair state and inter-triplet interactions have proved elusive. Here we use a range of organic semiconductors that undergo singlet exciton fission to reveal the photophysical properties of entangled triplet-pair states. We find that the triplet pair is bound with respect to free triplets with an energy that is largely material independentNature communicationsThe entangled triplet pair state in acene and heteroacene materials.PMC5510179EP/M01083X/1EP/K025651/1Bayliss SLClark JHerz LMResel RMeneau AYong CKMaruyama MTamura HHallani RKHotta SAnthony JEBubnova OSirringhaus HBeljonne DMusser AJLukman SfalseThe entangled triplet pair state in acene and heteroacene materials.Entanglement of states is one of the most surprising and counter-intuitive consequences of quantum mechanics, with potent applications in cryptography and computing. In organic materials, one particularly significant manifestation is the spin-entangled triplet-pair state, which mediates the spin-conserving fission of one spin-0 singlet exciton into two spin-1 triplet excitons. Despite long theoretical and experimental exploration, the nature of the triplet-pair state and inter-triplet interactions have proved elusive. Here we use a range of organic semiconductors that undergo singlet exciton fission to reveal the photophysical properties of entangled triplet-pair states. We find that the triplet pair is bound with respect to free triplets with an energy that is largely material independent2017-01-01T00:00:00Z2017 Jul2026-05-05T11:22:39.336Z2019-03-27T02:50:25ZS-EPMC55101792869963710.1038/ncomms15953