Klyachko, A. A.Can, M. A.Binicioǧlu, S.Shumovsky, A. S.2016-02-082016-02-0820080031-9007http://hdl.handle.net/11693/23062We resolve an old problem about the existence of hidden parameters in a three-dimensional quantum system by constructing an appropriate Bell's type inequality. This reveals the nonclassical nature of most spin-1 states. We shortly discuss some physical implications and an underlying cause of this nonclassical behavior, as well as a perspective of its experimental verification. © 2008 The American Physical Society.EnglishQuantum electronicsQuantum opticsThree dimensional1 systemsAmerican Physical Society (APS)Experimental verificationHidden variablesNonclassical behaviorQuantum systemsThree dimensional (3D)Spin dynamicsArticle10.1103/PhysRevLett.101.0204031079-7114