▎ 摘　　要

In this paper we show that (1) for graphene tubules an axial magnetic field can induce a semimetal-semiconductor transition periodically at zero bias. This is an Aharonov-Bohm-type effect and is generally true for thin cylindrical conductors; (2) the Landauer approach can be used to estimate the conductance of individual tubules measured by scanning tunneling probes as a function of applied bias, temperature, tubule geometric factors, and magnetic field. Numerical calculations are presented showing that the conductance modulation should be observable even at room temperature.