  In quantum chromodynamics, a gauge field configuration with nonzero
topological charge generates a difference between the number of left- and
right-handed quarks. When a (electromagnetic) magnetic field is added to this
configuration, an electromagnetic current is induced along the magnetic field;
this is called the chiral magnetic effect. We compute this current in the
presence of a color flux tube possessing topological charge, with a magnetic
field applied perpendicular to it. We argue that this situation is realized at
the early stage of relativistic heavy-ion collisions.
