Evidence of macroscopically entangled protons in a mixed isotope crystal of KH${}_p$D${}_{1-p}$CO${}_3$

Abstract

We examine whether protons and deuterons in the crystal of KH${}_{0.76}$D${}_{0.24}$CO${}_3$ at 300 K are particles or matter waves. The neutron scattering function measured over a broad range of reciprocal space reveals the enhanced diffraction pattern anticipated for antisymmetrized macroscopic states for protons (fermions). These features exclude a statistical distribution of protons and deuterons. Raman spectra are consistent with a mixture of KHCO${}_3$ and KDCO${}_3$ sublattices whose isomorphous structures are independent of the isotope content. We propose a theoretical framework for decoherence-free proton and deuteron states.

References in corpus (2)

• Classical world arising out of quantum physics under the restriction of coarse-grained measurements
• A neutron diffraction study of macroscopically entangled proton states in the high temperature phase of the KHCO3 crystal at 340 K