BASIC GATES OF QCA TECHNOLOGY:
MAJORITY GATE:
MAJORITY GATE:
QCA Majority Gate Perhaps the most important
logic gate in QCA is the majority gate. Figure 5 shows a majority gate with
three inputs and one output. In this structure, the electrical field effect of
each input on the output is identical and additive, with the result that
whichever input state ("binary 0" or "binary 1") is in the
majority becomes the state of the output cell — hence the gate's name. For
example, if inputs A and B exist in a “binary 0” state and input C exists in a
“binary 1” state, the output will exist in a “binary 0” state since the
combined electrical field effect of inputs A and B together is greater than
that of input C alone.
OTHER GATES:
Other types of gates, AND gate namely and
OR gate, can be constructed using a majority gate with fixed polarization on
one of its inputs. A NOT gate, on the other hand, is fundamentally different
from the majority gate, as shown in Figure 6. The key to this design is that
the input is split and both resulting inputs impinge obliquely on the output.
In contrast with an orthogonal placement, the electric field effect of this
input structure forces a reversal of polarization in the output.
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