Line-defect–induced Fano interference in an armchair graphene nanoribbon

Abstract

Electron transport through a metallic armchair graphene nanoribbon is theoretically investigated by considering the presence of line defect. The line defect is formed by the staggered stacking of the pentagons and heptagons. Our calculation results show that the line defect mainly destroys the electron transport in the conduction-band region by inducing the abundant Fano effects in the electron transport process. Moreover, the properties of the Fano effects are tightly dependent on the width M of the nanoribbon, and the results of M ≤ 17 are completely different from those of M > 17. The spectra of the density of electron states illustrate that the line defect induces some localized quantum states, and that the different localizations of these states lead to the distinct transport results. By analyzing the influence of the structure parameters, the Fano effects are described in detail. All the results demonstrate that such a structure can be a promising candidate for electron manipulation in graphene nanoribbon.

Electron confinement induced by diluted hydrogen-like ad-atoms in graphene ribbons

“…Since the low-energy oscillations appeared in both conductance and LDOS, it seems that scanning tunneling spectroscopy could be used to detect those oscillations, as they were already measured in carbon nanotubes. 11 Additionally, regardless of the distance between the doped regions, we observe the Fano-like resonances 45,67 in the average conductance, at energies corresponding to the van Hove singularities of the pristine system. This effect could be used to indirectly determine the width of the ribbons employed in the system.…”

Quantum control of nonlinear thermoelectricity at the nanoscale

“…Since nonlinear flows become a superposition of two Fano-type contributions, as in Eqs. (40) and (41), we can still apply much of the previous argument given for a noninteracting dot to an interacting dot. That means we expect enhanced thermoelectricity by the Fano resonance in an interacting dot as well.…”

“…31 and references therein). Experimental realizations of tunable Fano resonances include semiconductor quantum dots [32][33][34][35] or molecular junctions 36 as well as engineered graphenes or nanoribbons [37][38][39][40][41][42] . It is noteworthy that quantum coherence in some single-molecule junctions remains not only at low temperatures but also at room temperature [43][44][45][46][47][48][49] .…”

Thermoelectric efficiency of nanoscale devices in the linear regime

“…Impact of Breit-Wigner and Fano transmission shapes on the TE properties of nanostructured materials have been recognized for graphene quantum rings 45 and nanoribbons 22,46 but also for quantum dots 47,48 , and in the vast field of molecular electronics 19,49 for nanoscale molecular bridges and molecular wires, [50][51][52][53][54] and molecular constrictions. Noticeably, molecular junctions have been proposed 53 as optimal candidates for large values of the figure of merit ZT .…”