Researchers Bound Quantum Eigensolver Shots to Linear Scaling

Scientists are developing quantum subspace diagonalization methods as promising algorithms for quantum chemistry on near-term quantum computers. These methods can estimate low-lying energies of molecular systems using shallow quantum circuits. This estimation requires many circuit repetitions to determine the projection. A significant reduction in the per-matrix-element shot count needed for accurate quantum calculations has been achieved, improving the scaling from O(M³) to O(M), where M represents the number of reference states. This represents an advancement in the field of quantum computational chemistry, as the computational cost associated with determining molecular energies has historically been a major impediment to simulating larger systems. The…