Two-particle interference of electron pairs on a molecular level
  We investigate the photo-doubleionization of $H_2$ molecules with 400 eV photons. We find that the emitted electrons do not show any sign of two-center interference fringes in their angular emission distributions if considered separately. In contrast, the quasi-particle consisting of both electrons (i.e. the "dielectron") does. The work highlights the fact that non-local effects are embedded everywhere in nature where many-particle processes are involved. 
M. Waitz, D. Metz, J. Lower, C. Schober, M. Keiling, M. Pitzer, K.   Mertens, M. Martins, J. Viefhaus, S. Klumpp, T. Weber, ...
physics.atom-ph physics.atm-clus quant-ph