Implementation strategies for multiband quantum simulators of real materials

TL;DR

This paper explores how multiband quantum simulators can be designed to accurately mimic real materials, emphasizing the importance of optical lattice form and electron analogue interactions, with promising results using dressed Rydberg atoms.

Contribution

It demonstrates the necessity of non-sinusoidal optical lattices and identifies dressed Rydberg atoms as suitable for multiband quantum simulation of materials.

Findings

Bandstructure is highly sensitive to optical lattice form.

Non-sinusoidal potentials improve simulation accuracy.

Dressed Rydberg atoms can approximate real material interactions.

Abstract

The majority of quantum simulators treat simplified one-band strongly correlated models, whereas multiple bands are needed to describe materials with intermediate correlation. We investigate the sensitivity of multiband quantum simulators to: (1) the form of optical lattices (2) the interactions between electron analogues. Since the kinetic energy terms of electron analogues in a quantum simulator and electrons in a solid are identical, by examining both periodic potential and interaction we explore the full problem of many-band quantum simulators within the Born-Oppenheimer approximation. Density functional calculations show that bandstructure is highly sensitive to the form of optical lattice, and it is necessary to go beyond sinusoidal potentials to ensure that the bands closest to the Fermi surface are similar to those in real materials. Analysis of several electron analogue types finds that dressed Rydberg atoms (DRAs) have promising interactions for multi band quantum simulation. DRA properties can be chosen so that interaction matrices approximate those in real systems and decoherence effects are controlled, albeit with parameters at the edge of currently available technology. We conclude that multiband quantum simulators implemented using the principles established here could provide insight into the complex processes in real materials.