  Magnetic barriers in graphene are not easily tunable. However, introducing
both electric and magnetic fields, provides tunable and far more controllable
electronic states in graphene. Here we study such systems. A one-dimensional
channel can be formed in graphene using perpendicular electric and magnetic
fields. This channel (quantum wire) supports localized electron-hole states,
with parameters that can be controlled by an electric field. Such quantum wire
offers peculiar conducting properties, like unidirectional conductivity and
robustness to disorder. Two separate quantum wires comprise a waveguide with
two types of eigenmodes: one type is similar to traditional waveguides, the
other type is formed by coupled surface waves propagating along the boundaries
of the waveguide.
