Quantum eigensolver on extension of optimized binary configurations

초록

We developed a quantum eigensolver (QE), which is based on an extension of optimized binary configurations measured by quantum annealing (QA) on a D-Wave quantum annealer (D-Wave QA). This approach performs iterative QA measurements to optimize the eigenstates |v' ) without the derivation of a classical computer. The computational cost is rj ML for full eigenvalues E and |v') of the Hamiltonian H of size L x L , where M and rj are the number of QA measurements required to reach the converged |v' ) and the total annealing time of many QA shots, respectively. Unlike the exact diagonalization algorithm with L 3 iterations on a classical computer, the computation cost is not significantly affected by L and M because rj represents a very short time within 10-2 seconds on the D-Wave QA. We selected the tight-binding H that contains the exact E values of all energy states in two systems with metallic and insulating phases. We confirmed that the proposed QE algorithm provides exact solutions within the errors of 5 x 10-3. Finally, we believe that the newly developed QE algorithm will be widely used for various applications such as material and drug design.