Generalization of the Output of a Variational Quantum Eigensolver by Parameter Interpolation with a Low-depth Ansatz
Kosuke Mitarai, Tennin Yan, Keisuke Fujii · Physical Review Applied · 2019
Quantum computing hardware is now surpassing the 50-qubit level, which cannot be simulated with a classical computer. In practical use, generating the ground states of slightly different Hamiltonians ($e.g.$ induced by the different atomic coordinates in a molecule) is often required, but here the traditional form of the variational quantum eigensolver is inefficient. Thus the authors discuss ``training'' a quantum circuit with a small number of Hamiltonians and then generalizing the output by interpolation, and also propose a purpose-built quantum circuit, to greatly reduce the time needed to find ground states with a near-term quantum computer.