Abstract
Einstein was wrong with his 1927 Solvay Conference claim that quantum mechanics is incomplete and incapable of describing diffraction of single particles. However, the Einstein-Podolsky-Rosen paradox of entangled pairs of particles remains lurking with its 'spooky action at a distance'. In molecules quantum entanglement can be viewed as basis of both chemical bonding and excitonic states. The latter are important in many biophysical contexts and involve coupling between subsystems in which virtual excitations lead to eigenstates of the total Hamiltonian, but not for the separate subsystems. The author questions whether atomic or photonic systems may be probed to prove that particles or photons may stay entangled over large distances and display the immediate communication with each other that so concerned Einstein. A dissociating hydrogen molecule is taken as a model of a zero-spin entangled system whose angular momenta are in principle possible to probe for this purpose. In practice, however, spins randomize as a result of interactions with surrounding fields and matter. Similarly, no experiment seems yet to provide unambiguous evidence of remaining entanglement between single photons at large separations in absence of mutual interaction, or about immediate (superluminal) communication. This forces us to reflect again on what Einstein really had in mind with the paradox, viz. a probabilistic interpretation of a wave function for an ensemble of identically prepared states, rather than as a statement about single particles. Such a prepared state of many particles would lack properties of quantum entanglement that make it so special, including the uncertainty upon which safe quantum communication is assumed to rest. An example is Zewail's experiment showing visible resonance in the dissociation of a coherently vibrating ensemble of NaI molecules apparently violating the uncertainty principle. Einstein was wrong about diffracting single photons where space-like anti-bunching observations have proven recently their non-local character and how observation in one point can remotely affect the outcome in other points. By contrast, long range photon entanglement with immediate, superluminal response is still an elusive, possibly partly misunderstood issue. The author proposes that photons may entangle over large distances only if some interaction exists via fields that cannot propagate faster than the speed of light. An experiment to settle this 'interaction hypothesis' is suggested.
Highlights
Einstein was wrong with his 1927 Solvay Conference claim that quantum mechanics is incomplete and incapable of describing diffraction of single particles
In 1935, Einstein, Podolsky and Rosen (EPR) presented a paradox, which seemed to imply a fundamental discrepancy between quantum and classical mechanics and which they meant proves that the former is not a ‘complete theory’ (Einstein et al 1935)
Einstein (1936) says ‘Die Schrödinger-Gleichung bestimmt die zeitlichen Änderungen, welche die System-Gesamtheit erfärhrt, sei es ohne, sei es mit äusseren Einwirkungen auf Downloaded from httpcs:r/e/awtwivwec.coammmbroidngse.o.orrgg/l/iccoernes.eIPs/badyd/4r.e0s/s):,5w2h.8i7c.h16p1e.r7m3,iotsnu0n2rNesotvri2c0te2d1 raet-1u3s:e0,8d:3is4t,rsibuubtjeiocnt t,oanthderCeapmrobdruidcgteioCnoirne atenrymms oedf iuusme,apvraoilvaibdleedatthhettposr:i/g/iwnwalww.coarmkbirsidge.org/core/terms. https://doi.org/10.1017p/Sro00p3e3rl5y83c5it1e6d0. 00111 das Einzel-System.’. He was concerned by the simplification of using one wave function to describe a single-particle system and, that it may be prone to artifacts, due to weaker, disregarded but still potentially significant, perturbing interactions with the surroundings, if the predicted expectation is not adequately integrated with respect to all parameters involved
Summary
We may write a (spatial) electron wave function of a hydrogen-like molecule as (Griffiths, 2008):. The entangled state has no meaning until somebody tries to probe it – it is like opening a box to find out what spin one of the hydrogen radicals has, and puff!, the wave function collapses into one of the eigenstates With this view, it is the act of making a measurement that forces the system to react irrespective of how far away the two parts are from each other. A single-particle experiment would encounter a problem to resolve the wave packet motion because of the uncertainty principle, the quantum statistics of the large number of molecules coherently excited by a femtosecond pulse, to vibrate all of them in phase, will over-rule the uncertainty and provide macroscopic features to the oscillations, possible to experimentally follow as either activated complex or free atoms, appearing as ringing (resonance) particle emission intensities with coinciding temporal peak positions. (1) whether true correlation may be experimentally achieved between the two emitted photons (i.e. no time lag between their emissions), and (2) whether their polarizations may be considered known as a result of the design of the source
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
