Topological zero-line modes in folded bilayer graphene

Abstract

We theoretically investigate a folded bilayer graphene structure as an experimentally realizable platform to produce the one-dimensional topological zero-line modes. We demonstrate that the folded bilayer graphene under an external gate potential enables tunable topologically conducting channels to be formed in the folded region, and that a perpendicular magnetic field can be used to enhance the conducting when external impurities are present. We also show experimentally that our proposed folded bilayer graphene structure can be fabricated in a controllable manner. Our proposed system greatly simplifies the technical difficulty in the original proposal by considering a planar bilayer graphene (i.e., precisely manipulating the alignment between vertical and lateral gates on bilayer graphene), laying out a new strategy in designing practical low-power electronics by utilizing the gate induced topological conducting channels.

Transport induced dimer state from topological corner states

“…Two-dimensional insulators with nontrivial band topology have been widely studied in the past decades [1][2][3][4], which include quantum anomalous Hall effect [5][6][7][8][9][10], quantum spin Hall effect [11][12][13][14], quantum valley Hall effect [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31], and topological crystalline insulators [32][33][34]. These topological phases are characterized by nontrivial band topological in-dices as well as gapless edge states, which are robust against disorders and exhibit quantized conductivity [5-9, 13, 35-40].…”

Transport Induced Dimer State from Topological Corner States

“…Two-dimensional insulators with nontrivial band topology have been widely studied in the past decades [1][2][3][4] , which include quantum anomalous Hall effect [5][6][7][8][9][10] , quantum spin Hall effect [11][12][13][14] , quantum valley Hall effect [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] , and topological crystalline insulators [32][33][34] . These topological phases are characterized by nontrivial band topological indices as well as gapless edge states, which are robust against disorders and exhibit quantized conductivity [5][6][7][8][9]13,[35][36][37][38][39][40] .…”

Spontaneous Folding Growth of Graphene on h-BN

“…To date, various approaches have been conducted to achieve edge-folded bilayer graphene (EFBG). The most common method has focused on mechanical techniques, including random folding or self-peeling during exfoliation, , sonification or stirring in solution, , and precisely folding by scanning probes. , Besides, Joule heating and chemical modification are also utilized to achieve folded graphene. − However, some of these methods possess large randomness, some need complicated operations, and even some will cause the quality decay of graphene sheets. Here, we use a simple chemical vapor deposition (CVD) method to demonstrate that high-quality EFBG can be spontaneously grown on the h-BN substrate.…”

“…2 To date, various approaches have been conducted to achieve edge-folded bilayer graphene (EFBG). The most common method has focused on mechanical techniques, including random folding or self-peeling during exfoliation, 21,22 sonification or stirring in solution, 23,24 and precisely folding by scanning probes. 25,26 Besides, Joule heating and chemical modification are also utilized to achieve folded graphene.…”