Manipulation of domain-wall solitons in bi- and trilayer graphene

Abstract

Topological dislocations and stacking faults greatly affect the performance of functional crystalline materials. Layer-stacking domain walls (DWs) in graphene alter its electronic properties and give rise to fascinating new physics such as quantum valley Hall edge states. Extensive efforts have been dedicated to the engineering of dislocations to obtain materials with advanced properties. However, the manipulation of individual dislocations to precisely control the local structure and local properties of bulk material remains an outstanding challenge. Here we report the manipulation of individual layer-stacking DWs in bi- and trilayer graphene by means of a local mechanical force exerted by an atomic force microscope tip. We demonstrate experimentally the capability to move, erase and split individual DWs as well as annihilate or create closed-loop DWs. We further show that the DW motion is highly anisotropic, offering a simple approach to create solitons with designed atomic structures. Most artificially created DW structures are found to be stable at room temperature.

In situ manipulation and switching of dislocations in bilayer graphene

“…Dislocations in bilayer graphene have been characterized using transmission electron microscopy (TEM) ( 10 , 11 ) in the free-standing case and near-field infrared nanoscopy ( 13 , 18 ) in the non–free-standing (supported) case, where dislocation manipulations have been recently demonstrated by Jiang et al . ( 21 ). Here, we present an alternative way to visualize defects in free-standing bilayer graphene by using SEM in the transmission mode (tSEM).…”

Anisotropic Strain-Induced Soliton Movement Changes Stacking Order and Band Structure of Graphene Multilayers: Implications for Charge Transport

“…To identify the cause of the transition, we apparently need to test if during our process steps effects occur that can lead to a stacking transformation, with special attention to mechanisms that are also known to induce folds. A few methods including applying an electrical field 29 , strain 30 , high temperatures 31 , doping 32 , an electron beam 22 and recently also a mechanical force 33 have been reported to cause a movement of solitons or a transformation between Bernal and rhombohedral graphene or vice versa. Since we do not apply an electric field across the flake, we can exclude this directly as possible trigger for a transformation.…”

Commensurate-incommensurate phase transition and a network of domain walls in bilayer graphene with a biaxially stretched layer

“…1,[15][16][17][18] The variation of the stacking is mostly localized in narrow strips with the width much smaller than the size of commensurate domains where the stacking is close to the ground-state one. These narrow strips are referred to as domain walls [2][3][4][5]7,8 or boundaries between commensurate domains. 1,[15][16][17][18] In previous theoretical works, 1,3,4,15,16,18,19 it was assumed that domain walls do not cross as long as the distance between them is large and can be treated as isolated.…”