Demonstration of Variational Quantum Eigensolver with Solid-State Spin System under Ambient Conditions

Quantum simulators offer the potential to utilize the quantum nature of a physical system to study another physical system. In contrast to conventional simulation, which experiences an exponential increase in computational complexity, quantum simulation costs only linearly with the increasing size of the problem, rendering it a promising tool for applications in quantum chemistry. The Variational Quantum Eigensolver (VQE) algorithm is a particularly promising application for investigating molecular electronic structures. For its experimental implementation, spin-based solid-state qubits have the advantage of long decoherence time and high-fidelity quantum gates, which can lead to high accuracy in the ground state finding. This study employs the nitrogen-vacancy (NV) center system in diamond to implement the VQE algorithm and successfully finds the eigenvalue of a specific Hamiltonian.