Quantum Fabry-Perot Resonator: Extreme Angular Selectivity in Matter-Wave Tunneling

The simple quantum setup of a Fabry-Perot interferometer is found to exhibit very high directional preference to impinging particle beams, with use of realistic media. Numerous optimized designs, acting as extremely sharp angular filters of matter waves, are determined by trying and testing every single combination of actual materials picked from a long list. Two types of resonances are identified whose different mechanisms are demonstrated through the spatial distribution of wave-function magnitude and probability current, while their robustness with respect to fabrication defects is also examined. Such findings offer additional degrees of freedom when designing architectures for a broad range of quantum-engineering applications that involve beam tunneling and provide a set of limits for the angular selectivity that can be achieved with the considered geometry.