Matterwave interferometry is a promising and successful way to explore truly macroscopic quantum phenomena and probe the validity of quantum theory at the borderline to the classic world. Indeed, we may soon witness quantum superpositions with nano to micrometer-sized objects. Yet, venturing deeper into the macroscopic domain is not only an experimental but also a theoretical endeavour: new interferometers must be conceived, sources of noise and decoherence identified, size effects understood and possible modifications of the theory taken into account. This thesis provides the theoretical background to recent advances in molecule and nanoparticle interferometry. In addition, it contains a physical and objective method to assess the degree of macroscopicity of such experiments, ranking them among other macroscopic quantum superposition phenomena.

Nominated as an outstanding Ph.D. thesis by the University of Vienna, Austria Detailed phase-space description of matter-wave interferometry in the near field Mie theory treatment of nano spheres interacting with gaussian standing-wave modes Comparison of the most macroscopic matter-wave quantum experiments ever performed or proposed Includes supplementary material: sn.pub/extras

Inhalt
Introduction.- Interaction of Polarizable Particles with Light.- Near-Field Interference Techniques with Heavy Molecules and Nanoclusters.- Classicalization and the Macroscopicity of Quantum Superposition States.- Conclusion and Outlook.- Appendix A Light-Matter Interaction.- Appendix B Matter-Wave Interferometry.- Appendix C Classicalization and Macroscopicity.