Experimental Determination of Electronic States via Digitized Shortcut-to-Adiabaticity and Sequential Digitized Adiabaticity

TL;DR

This paper demonstrates a novel quantum simulation method combining digitized shortcut-to-adiabaticity and sequential digitized adiabaticity on superconducting devices to accurately determine electronic states in molecules and topological models.

Contribution

It introduces a new combined approach for quantum state determination using digitized adiabatic techniques on superconducting quantum devices, applied to molecular and topological systems.

Findings

Successfully determined H2 molecular states and energy landscapes.

Accurately obtained valence and conduction bands of the BHZ model.

Simulated ground states of hydrogen chains with 3-6 atoms.

Abstract

A combination of the digitized shortcut-to-adiabaticity (STA) and the sequential digitized adiabaticity is implemented in a superconducting quantum device to determine electronic states in two example systems, the H2 molecule and the topological Bernevig-Hughes-Zhang (BHZ) model. For H2, a short internuclear distance is chosen as a starting point, at which the ground and excited states are obtained via the digitized STA. From this starting point, a sequence of internuclear distances is built. The eigenstates at each distance are sequentially determined from those at the previous distance via the digitized adiabaticity, leading to the potential energy landscapes of H2. The same approach is applied to the BHZ model, and the valence and conduction bands are excellently obtained along the X-{\Gamma}-X linecut of the first Brillouin zone. Furthermore, a numerical simulation of this method is performed to successfully extract the ground states of hydrogen chains with the lengths of 3 to 6 atoms.