  Quantum computing using two-dimensional NMR has recently been described using
scalar coupling evolution technique [J. Chem. Phys.,109,10603 (1998)]. In the
present paper, we describe two-dimensional NMR quantum computing with the help
of selective pulses. A number of logic gates are implemented using two and
three qubits with one extra observer spin. Some many-in-one gates (or
Portmanteau gates) are implemented. Toffoli gate (or AND/NAND gate) and OR/NOR
gates are implemented on three qubits. Deutsch-Jozsa quantum algorithm for one
and two qubits, using one extra work qubit, has also been implemented using
selective pulses after creating a coherent superposition state, in the
two-dimensional methodology.
