  In a multi-terminal setup, when time-reversal symmetry is broken by a
magnetic field, the heat flows can be managed by designing a device with
programmable Boolean behavior. We show that such device can be used to
implement operations like on/off switching, reversal, selected splitting and
swap of the heat currents. For each feature, the switching from one working
condition to the other is obtained by inverting the magnetic field. This offers
interesting opportunities of conceiving a programmable setup, whose operation
is controlled by an external parameter (the magnetic field) without need to
alter voltage and thermal biases applied to the system. Our results, generic
within the framework of linear response, are illustrated by means of a
three-terminal electronic interferometer model.
