Quantum marking and quantum erasure for neutral kaons.

The neutral kaon system is shown to be suitable to discuss extensions and tests of Bohr's complementarity principle through the quantum marking and quantum erasure techniques suggested by Scully and Drühl [Phys. Rev. A 25, 2208 (1982)]]. Strangeness oscillations play the role of the traditional interference pattern linked to wavelike behavior, whereas the different propagation in free space of the K(S) and K(L) components mimics the two possible interferometric paths taken by particlelike objects.