A state-averaged orbital-optimized hybrid quantum-classical algorithm for a democratic description of ground and excited states

Solving nonlinear differential equations with differentiable quantum circuits

“…The paradigmatic hybrid algorithm corresponds to the variational quantum eigensolver (VQE) [42,43], where a quantum computer is used to prepare parametrized quantum states and measure their energy, while classical optimization is used for finding the best variational parameters. This strategy enables quantum calculations with relatively noisy devices, and allows for numerous advances from the experimental [44][45][46][47][48][49][50][51][52] and theo-retical [53][54][55][56][57][58][59][60][61][62][63][64][65][66] perspectives.…”