Quantum chemistry on quantum computers

Quantum computing and quantum information processing technology have attracted attention in recently emerging fields. Among many important and fundamental issues in science, solving the Schroedinger equation (SE) of atoms and molecules is one of the ultimate goals in chemistry, physics and their related fields. SE is the first principle of non-relativistic quantum mechanics, whose solutions, termed wave functions, can afford any information of electrons within atoms and molecules, predicting their physicochemical properties and chemical reactions.

Dr. K. Sugisaki, Profs. K. Sato and T. Takui and coworkers, all researchers from Osaka City University (OCU) in Japan, have found a novel quantum algorithm enabling us to perform full configuration interaction (Full-CI) calculations suitable for "chemical reactions" without exponential/combinatorial explosion. Full-CI gives the exact numerical solutions of SE, which are intractable problems even for supercomputers. Such a quantum algorithm contributes to the acceleration of implementing practical quantum computers. Since 1929, chemistry and physics have sought to predict complex chemical reactions by invoking Full-CI approaches, but they have never been successful until now. Full-CI calculations are potentially capable of predicting chemical reactions. The researchers of the current study report a new Full-CI approach implemented on quantum computers for the first time.

The paper is published in ACS Central Science.