  Recent development in fabrication of hybrid nanostructures allows for
creation of quantum interferometers that combine semiconductor and
superconductor materials. We show that in those nanostructures the joint
phenomena of Aharonov-Bohm effect and Andreev reflections can be used to
determine the length on which the electron is retro-reflected as a hole. We
propose to exploit this feature for probing of the quasiparticle coherence
length in semiconductor-superconductor hybrids by a magnetoconductance
measurement.
