BIG Entanglement meets X-rays
Entanglement, spin and tunneling are TRUE quantum effects, because they do NOT have any classical counterpart. The quest of quantum entanglement was initiated by the famous EPR attack on quantum theory by Einstein, Boris Podolsky and Nathan Rosen in 1935. It is quite interesting that such serious suspicion has turned into the core of quantum world and has became the foundation of quantum technology. Over the past decades physicists have established many methods of creating entanglement between particles, photons (by SPDC) and even remote macroscopic objects (by DLCZ) with low energy photons, e.g., optical. Motivated by the commission of coherent X-ray sources, i.e., X-ray Free Electron Lasers (XFELs), the extension of quantum optics to hard X-rays is under study. In Sci. Rep. 6, 33361 (2016), we theoretically investigate the generation of the entanglement between two macroscopic objects with the ingredients of LLL X-ray interferometer, X-ray parametric down conversion source (XPDC) and two separated iron borate crystals. Here are the novel features of our scheme:
room temperature handling.
long coherence times of 141ns.
solid-state macroscopical samples with a large number of constituents.
the first scheme to directly manipulate macroscopic entangled objects while other proposals or experiments rather aim at manipulating the single photon that is used to entangle the macroscopic objects. This may provide a stronger evidence of nonlocality of macroscopic entanglement.
we present the possibility of using an XPDC setup as a heralded single X-ray photon source.