  Based on electron spins in semiconductor quantum dots as qubits, a new
quantum controlled-NOT(CNOT) gate is constructed in solid nanostructure without
resorting to spin-spin interactions. Single electron tunneling technology and
coherent quantum-dot cellular automata architecture are used to generate an
ancillary charge entangled state. Using the ancillary charge entangled state as
an intermediate state, we obtain a spin entangled state and design a CNOT gate
by using only single spin rotations.
