  The oscillation of photoluminescence peak energies is observed in InAs
quantum tubes depending on the magnetic flux through the tube. The oscillation
is shown to be due to the Aharonov-Bohm effect of a charged exciton in a
quantum tube. No quadratic shift in photoluminescence peak energies is
observed, which is a characteristic feature of a thin quantum tube with a
single channel surrounding the magnetic flux through the tube.
