Quantum computing using rotational modes of two polar molecules

In this paper, we numerically constructed general-purpose phase-correct global quantum gates by using intermolecular rotational modes of two polar molecules coupled by dipole-dipole interaction to encode two qubits and implement the Deutsch-Jozsa algorithm. The calculations were based on the multi-target optimal control theory (MTOCT). The molecular systems we examined were NaCl-NaBr, NaCl-NaCl, and NaBr-NaBr polar molecular systems. The rotational states in the ground vibrational state of the ground electronic state of these pairs were taken as two qubits. When implementing the Deutsch-Jozsa algorithm by combining these elementary gates, we obtained a maximum probability 97.95% for NaBr-NaBr system with the interval R = 5.0 nm in the repulsive configuration, which is the best performance of the two-state Deutsch-Jozsa algorithm compared with intramolecular vibrational-vibrational, vibrational-rotational, and electronic-vibrational qubits reported so far.