Introduction of paper: Elucidating reaction mechanisms on quantum computers | PNAS.
In this article, we introduce a paper that summarizes the current computational time for polymer catalytic systems using quantum computers. FeMoco is an abbreviation of Ferroum-Moribtenium-cofactor, which is expected to be used as a catalyst in ammonia synthesis because of its ability to fix nitrogen. FeMoco is an abbreviation of Ferroum-Moribtenium-cofactor, which is expected to be a catalyst for ammonia synthesis because it fixes nitrogen. Half a century after the Industrial Revolution, Malthus predicted a food crisis in his theory of population, showing that while population increases geometrically, food increases only arithmetically. In this context, Haber and Bosch and their colleagues succeeded in industrializing a method of synthesizing ammonia. This was called the Haber-Bosch process, and it was the first industrial attempt to mass-produce ammonia in Germany at the beginning of the 20th century, which led to an increase in food production. Now that we have better catalysts, our ability to produce ammonia has improved.
Using the density matrix renormalization group, the maximum number of qubits that can be solved using the Complete active space self-consistent field (CASSCF) method can be increased from 18 to 100. The quantum phase estimation was performed in single-threaded, multi-threaded, and nested calculations to estimate the computation time and the number of qubits required for the case of spin moment S=0, charge +3, 54 electrons, 54 orbitals, and the case of spin moment S=0, charge 0, 57 orbitals, 63 electrons in FeMoco. As a result, the amount of error was reduced to the exact solution. The results showed that it would take more than three years to keep the error within 0.1 mHartree of the exact solution with about 100 qubits for both single-threaded cases. On the other hand, in a multi-threaded system, the calculation was completed in three months with about 2000 qubits.
It has been four years since this paper was published, but the situation does not seem to have changed much. IBM is planning to release a 2000-qubit quantum computer the year after next, but I am not sure if the situation will improve.