A Simulation of Hydrazine Molecule^s Potential Energy Surface using Variational Quantum Eigensolver Algorithm
Godwin Gomosma (a*), Mohammad Kemal Agusta (a), Hermawan Kresno Dipojono(a)

(a) Engineering Physics, Bandung Institute of Technology
Jalan Ganesha 10, Bandung 40132, Indonesia
*23321303[at]mahasiswa.itb.ac.id

Abstract

Quantum computing is a technology that utilizes the principles of quantum mechanics to perform complex computational processes. In this work, we use Qiskit Module from IBM to do quantum computational calculation using Variational Quantum Eigensolver (VQE) algorithm. VQE is a hybrid quantum-classical method that combines a quantum computer to measure energies and a classical computer to process the measurement results and update the parameters of the quantum computer. The purpose of VQE is to find the ground state energy of a chemical system. In the previous study, many of the VQE calculations have been done on simple molecule like Hydrogen, Water, and Lithium Hydride. So, in this study, we would like use Hydrazine molecule as our object of VQE calculation. Furthermore, these results will be compared with the results from the classical calculation (MP2, CCSD, QCISD, and CASSCF) methods using Gaussian 09 software for testing the effectiveness and efficiency of VQE using Unitary Coupled-Cluster Single and Double excitations (UCCSD) Ansatz. The quantum algorithm based on the UCCSD Ansatz led to a simplification of the algorithm by reducing the circuit depth. Then, the possibility to use active spaces, can be used to reduce the quantum gates while trying to keep a good level of accuracy. In this study, we chose (2,2) and (4,4) active spaces. Based on the results, it is possible to design a quantum algorithm based on the UCCSD Ansatz for the solution of electronic structure problems on currently available quantum computers.

Keywords: VQE- Quantum Computation- Qiskit- Unitary Coupled Cluster Ansatz-

Topic: Modelling and Computational Physics