  Reversible logic allows low power dissipating circuit design and founds its
application in cryptography, digital signal processing, quantum and optical
information processing. This paper presents a novel quantum cost efficient
reversible BCD adder for nanotechnology based systems using PFAG gate. It has
been demonstrated that the proposed design offers less hardware complexity and
requires minimum number of garbage outputs than the existing counterparts. The
remarkable property of the proposed designs is that its quantum realization is
given in NMR technology.
