  In this comment, we point out some shortcomings in two papers "Fractional
quantum mechanics" [Phys. Rev. E 62, 3135 (2000)] and "Fractional Schroedinger
equation" [Phys. Rev. E 66, 056108 (2002)]. We prove that the fractional
uncertainty relation does not hold generally. The probability continuity
equation in fractional quantum mechanics has a missing source term, which leads
to particle teleportation, i.e., a particle can teleport from one place to
another. Since the relativistic kinetic energy can be viewed as an approximate
realization of the fractional kinetic energy, the particle teleportation should
be an observable relativistic effect in quantum mechanics. With the help of
this concept, superconductivity could be viewed as the teleportation of
electrons from one side of a superconductor to another and superfluidity could
be viewed as the teleportation of helium atoms from one end of a capillary tube
to the other. We also point out how to teleport a particle to a destination.
