Expressibility-Dependent Efficiency and Accuracy of Hardware Efficient Ansatz for Electronic Structure Calculations
Rasyid Ustman Ramadhan^1,Teguh Budi Prayitno^1, Yanoar P. Sarwono^2

1Department of Physics, Faculty of Mathematics and Natural Science, Jakarta State University, East Jakarta 13220, Indonesia
2Research Center for Quantum Physics, National Research and Innovation Agency (BRIN), South Tangerang 15314, Indonesia

Abstract

Variational quantum eigensolver (VQE) holds promise for solving the Schrodinger equation on noisy intermediate-scale quantum (NISQ) computers, with its success relying on a well-designed wave function ansatz. In this work, we calculate the total energy of the hydrogen molecule using five hardware efficient ansatz. Furthermore, we evaluate their expressibility and link it to the efficiency and the accuracy of the energy calculations. Understanding the expressibility of an ansatz is crucial for efficient quantum computation.

Keywords: VQE, expressibility

Topic: Instrumentation and Computational Physics