Quasi-bound states and Fano effect in T-shaped graphene nanoribbons

Xu, Jiong; Wang, L.; Weng, M. Q.

doi:10.1063/1.4824183

Cited by 12 publications

(7 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…43,44 . Various multi-terminal GNR geometries have also been addressed, both in-plane GNR devices [45][46][47][48] and tunneling junctions formed between GNRs. 47,[49][50][51][52] Finite-bias calculations in a multiterminal context were pioneered by Saha et al 53 and are becoming increasingly accessible in first-principles transport codes, such as the post-processing tool Gollum 54 and the open-source, self-consistent methods of Tran-Siesta.…”

Section: Introductionmentioning

confidence: 99%

A tunable electronic beam splitter realized with crossed graphene nanoribbons

Brandimarte

Engelund

Papior

et al. 2017

The Journal of Chemical Physics

View full text Add to dashboard Cite

Graphene nanoribbons (GNRs) are promising components in future nanoelectronics due to the large mobility of graphene electrons and their tunable electronic band gap in combination with recent experimental developments of on-surface chemistry strategies for their growth. Here we explore a prototype 4-terminal semiconducting device formed by two crossed armchair GNRs (AGNRs) using state-of-the-art first-principles transport methods. We analyze in detail the roles of intersection angle, stacking order, inter -GNR separation, and finite voltages on the transport characteristics. Interestingly, when the AGNRs intersect at θ = 60 • , electrons injected from one terminal can be split into two outgoing waves with a tunable ratio around 50% and with almost negligible back-reflection. The splitted electron wave is found to propagate partly straight across the intersection region in one ribbon and partly in one direction of the other ribbon, i.e., in analogy of an optical beam splitter. Our simulations further identify realistic conditions for which this semiconducting device can act as a mechanically controllable electronic beam splitter with possible applications in carbonbased quantum electronic circuits and electron optics. We rationalize our findings with a simple model that suggests that electronic beam splitters can generally be realized with crossed GNRs. arXiv:1611.03337v1 [cond-mat.mes-hall]

show abstract

Section: Introductionmentioning

confidence: 99%

A tunable electronic beam splitter realized with crossed graphene nanoribbons

Brandimarte

Engelund

Papior

et al. 2017

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…In particular, a localized state appears at the intersection of the three-terminal structure and induces the Fano line shape in the bias dependence of the conductance. [35][36][37][38][39][40][41][42] Thus, it is expected that there are also some interesting features in the T -shaped Majorana nanostructure. Furthermore, the unique property of this system can be shown in a simple view.…”

Section: Introductionmentioning

confidence: 99%

Majorana fermions in T-shaped semiconductor nanostructures

Zhou¹,

Wu²

2014

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

We investigate the Majorana fermions in a T -shaped semiconductor nanostructure with the Rashba spin-orbit coupling and a magnetic field in the proximity of an s-wave superconductor. It is found that the properties of the low-energy modes (including the Majorana and near-zeroenergy modes) at the ends of this system are similar to those in the Majorana nanowire. However, very distinct from the nanowire, one Majorana mode emerges at the intersection of the T -shaped structure when the number of the low-energy modes at each end N is odd, whereas neither Majorana nor near-zero-energy mode appears at the intersection for even N . We also discover that the intersection Majorana mode plays an important role in the transport through the above T -shaped nanostructure with each end connected with a normal lead. Due to the presence of the intersection mode, the deviation of the zero-bias conductance from the ideal value in the long-arm limit N e 2 /h is more pronounced in the regime of odd N compared to the one of even N . Furthermore, when the magnetic field increases from the regime of odd N to the one of even N + 1, the deviation from the ideal value tends to decrease. This behavior is also very distinct from that in a nanowire, where the deviation always tends to increase with the increase of magnetic field.

show abstract

“…GNRs behave as singlechannel room-temperature ballistic electrical conductors on a length scale greater than ten microns [23]. Therefore, they are good candidates to exploit quantum effects such as the Fano effect [24,25,26,27,28,29], resonant tunneling [30,31,32] and quantum size effects [33,34], even at room temperature. GNRs are commonly referred to as graphene nanoconstrictions (GNCs) or quantum point contacts when their length is close to their width.…”

mentioning

confidence: 99%

Quantized Electron Transport Through Graphene Nanoconstrictions

Clericò

Delgado-Notario

Saiz-Bretín

et al. 2018

Physica Status Solidi (a)

View full text Add to dashboard Cite

Here, the quantization of Dirac fermions in lithographically defined graphene nanoconstrictions is studied. Quantized conductance is observed in single nanoconstrictions fabricated on top of a thin hexamethyldisilazane layer over a Si/SiO2 wafer. This nanofabrication method allows to obtain well defined edges in the nanoconstrictions, thus reducing the effects of edge roughness on the conductance. The occurrence of ballistic transport is proved and several size quantization plateaus are identified in the conductance at low temperature. Experimental data and numerical simulations show good agreement, demonstrating that the smoothening of the plateaus is not related to edge roughness but to quantum interference effects.

show abstract

Quasi-bound states and Fano effect in T-shaped graphene nanoribbons

Cited by 12 publications

References 45 publications

A tunable electronic beam splitter realized with crossed graphene nanoribbons

A tunable electronic beam splitter realized with crossed graphene nanoribbons

Majorana fermions in T-shaped semiconductor nanostructures

Quantized Electron Transport Through Graphene Nanoconstrictions

Contact Info

Product

Resources

About