Abstract

We investigate the emergence and topological nature of interface states (IFs) in N-AGNR/(N−2)-AGNR/N-AGNR heterostructure segments lacking translational symmetry, focusing on their relation to the end states of the constituent armchair graphene nanoribbon segments. Using a real-space bulk boundary perturbation approach and a tight-binding model, we show that opposite-chirality states hybridize through junction-site perturbations and that the number and chirality of IFs in symmetric AGNRHs are determined by the difference between the end states of the outer and central segments. Calculated transmission spectra reveal that AGNRHs host a topological double quantum dot when IFs originate from the end states of the central AGNR segment. Using an Anderson model with effective intra-dot and inter-dot Coulomb interactions, we derive an analytical expression for tunneling current through the TDQD and analyze nonlinear thermoelectric power output under Coulomb blockade.

Abstract

We investigate the emergence and topological nature of interface states (IFs) in N-AGNR/(N−2)-AGNR/N-AGNR heterostructure segments lacking translational symmetry, focusing on their relation to the end states of the constituent armchair graphene nanoribbon segments. Using a real-space bulk boundary perturbation approach and a tight-binding model, we show that opposite-chirality states hybridize through junction-site perturbations and that the number and chirality of IFs in symmetric AGNRHs are determined by the difference between the end states of the outer and central segments. Calculated transmission spectra reveal that AGNRHs host a topological double quantum dot when IFs originate from the end states of the central AGNR segment. Using an Anderson model with effective intra-dot and inter-dot Coulomb interactions, we derive an analytical expression for tunneling current through the TDQD and analyze nonlinear thermoelectric power output under Coulomb blockade.

Abstract

We investigate the emergence and topological nature of interface states (IFs) in N-AGNR/(N−2)-AGNR/N-AGNR heterostructure segments lacking translational symmetry, focusing on their relation to the end states of the constituent armchair graphene nanoribbon segments. Using a real-space bulk boundary perturbation approach and a tight-binding model, we show that opposite-chirality states hybridize through junction-site perturbations and that the number and chirality of IFs in symmetric AGNRHs are determined by the difference between the end states of the outer and central segments. Calculated transmission spectra reveal that AGNRHs host a topological double quantum dot when IFs originate from the end states of the central AGNR segment. Using an Anderson model with effective intra-dot and inter-dot Coulomb interactions, we derive an analytical expression for tunneling current through the TDQD and analyze nonlinear thermoelectric power output under Coulomb blockade.

Abstract

We investigate the emergence and topological nature of interface states (IFs) in N-AGNR/(N−2)-AGNR/N-AGNR heterostructure segments lacking translational symmetry, focusing on their relation to the end states of the constituent armchair graphene nanoribbon segments. Using a real-space bulk boundary perturbation approach and a tight-binding model, we show that opposite-chirality states hybridize through junction-site perturbations and that the number and chirality of IFs in symmetric AGNRHs are determined by the difference between the end states of the outer and central segments. Calculated transmission spectra reveal that AGNRHs host a topological double quantum dot when IFs originate from the end states of the central AGNR segment. Using an Anderson model with effective intra-dot and inter-dot Coulomb interactions, we derive an analytical expression for tunneling current through the TDQD and analyze nonlinear thermoelectric power output under Coulomb blockade.