A group of researchers at IBM conducted a study on beryllium hydride – or BeH2 with quantum computers implementing a new quantum algorithm capable of efficient computation of the lowest energy states.
That’s where the quantum computer comes into the play. With the proper algorithm, a quantum computer can handle the problem easily.
To make it work on IBM quantum computer, the researchers had to develop a very efficient quantum algorithm by extracting the maximal quantum computational power out of their seven-qubit processor.
A hardware-efficient quantum circuit that utilizes the naturally available gate operations in the quantum processor is used to prepare trial ground states of the Hamiltonian.
The quantum processor is driven to the trial ground state, and measurements are performed that allow us to evaluate the energy of the prepared trial state.
The measured energy values are fed to a classical optimization routine that generates the next quantum circuit to drive the quantum processor to, in order to further reduce the energy.