Entanglement beating in free space through spin–orbit coupling

作     者：Eileen Otte Carmelo Rosales-Guzmán Bienvenu Ndagano Cornelia Denz Andrew Forbes 

作者机构：Institute of Applied PhysicsUniversity of MuensterMuenster D-48149Germany School of PhysicsUniversity of the WitwatersrandWits 2050South Africa 

出 版 物：《Light(Science & Applications)》 (光（科学与应用)（英文版）)

年 卷 期：2018年第7卷第1期

页      面：1040-1046页

核心收录：

学科分类：07[理学] 070201[理学-理论物理] 0702[理学-物理学] 

基　　金：support from the German Research Foundation DFG(EXC 1003–CiM,TRR61) CRG from the Claude Leon foundation BN from the National Research Foundation of South Africa 

主　　题：classical entanglement complex light fields entanglement oscillation spin-orbit coupling 

摘      要：It is well known that the entanglement of a quantum state is invariant under local unitary *** rule dictates,for example,that the entanglement of internal degrees of freedom of a photon remains invariant during free-space ***,we outline a scenario in which this paradigm does not *** local Bell states engineered from classical vector vortex beams with non-separable degrees of freedom,the so-called classically entangled states,we demonstrate that the entanglement evolves during propagation,oscillating between maximally entangled(purely vector)and product states(purely scalar).We outline the spin–orbit interaction behind these novel propagation dynamics and confirm the results experimentally,demonstrating spin–orbit coupling in paraxial *** demonstration highlights a hitherto unnoticed property of classical entanglement and simultaneously offers a device for the on-demand delivery of vector states to targets,for example,for dynamic laser materials processing,switchable resolution within stimulated emission depletion(STED)systems,and a tractor beam for entanglement.