Vertically Coupled Double Quantum Dots Connected In Parallel

TL;DR

This paper investigates a ring-shaped quadruple quantum dot system with vertical coupling, revealing charge transport properties, Coulomb diamonds, and potential for exploring complex quantum phases in engineered lattice structures.

Contribution

It introduces a novel quadruple quantum dot architecture with vertical coupling and parallel configuration, enabling detailed study of isospin effects and correlation phenomena.

Findings

Observation of Coulomb diamonds in the system

Evaluation of interlayer energy offset

Potential to study interaction-driven quantum phases

Abstract

We report charge transport measurements in a ring-shaped quadruple quantum dot system, composed of two vertically coupled double quantum dots connected in parallel. The vertical coupling introduces an isospin degree of freedom tied to the layer index, and the parallel configuration enables independent access to each quantum dot pair. This design allows us to observe Coulomb diamonds and evaluate the interlayer energy offset. By extending this platform to triangular and hexagonal artificial lattices, we explore correlation effects such as isospin frustration. These results highlight the system's potential for studying interaction-driven quantum phases.