# Double quantum dots defined in bilayer graphene

## TL;DR

This paper investigates double quantum dots in bilayer graphene using atomistic and continuum models, revealing how electron wave functions and interdot coupling influence the quantum states and energy spectrum.

## Contribution

It introduces a detailed analysis of electron wave functions and interdot coupling effects in bilayer graphene quantum dots, combining atomistic and continuum approaches.

## Key findings

- Wave functions have opposite parities on sublattices in both layers.
- Ground state wave functions switch from bonding to antibonding with interdot distance.
- Two-electron states show symmetric or antisymmetric spatial configurations.

## Abstract

Artificial molecular states of double quantum dots defined in bilayer graphene are studied with the atomistic tight-binding and its low-energy continuum approximation. We indicate that the extended electron wave functions have opposite parities on each of the sublattices at both graphene layers and that the ground-state wave function components change from bonding to antibonding with the interdot distance. In the weak coupling limit -- the most relevant for the quantum dots defined electrostatically -- the signatures of the interdot coupling include -- for the two-electron ground state -- formation of states with symmetric or antisymmetric spatial wave functions split by the exchange energy. In the high energy part of the spectrum the states with both electrons in the same dot are found with the splitting of energy levels corresponding to simultaneous tunneling of the electron pair from one dot to the other.