  We explore AND gate response in a double quantum ring where each ring is
threaded by a magnetic flux $\phi$. The double quantum ring is attached
symmetrically to two semi-infinite one-dimensional metallic electrodes and two
gate voltages, namely, $V_a$ and $V_b$, are applied, respectively, in the lower
arms of the two rings which are treated as two inputs of the AND gate. The
system is described in the tight-binding framework and the calculations are
done using the Green's function formalism. Here we numerically compute the
conductance-energy and current-voltage characteristics as functions of the
ring-to-electrode coupling strengths, magnetic flux and gate voltages. Our
study suggests that, for a typical value of the magnetic flux $\phi=\phi_0/2$
($\phi_0=ch/e$, the elementary flux-quantum) a high output current (1) (in the
logical sense) appears only if both the two inputs to the gate are high (1),
while if neither or only one input to the gate is high (1), a low output
current (0) results. It clearly demonstrates the AND gate behavior and this
aspect may be utilized in designing an electronic logic gate.
