Quantum computing using rotational modes of two polar molecules

Abstract

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.