Charge-polarized interfacial superlattices in marginally twisted hexagonal boron nitride.
Charge-polarized interfacial superlattices in marginally twisted hexagonal boron nitride.
复制标题
边缘扭曲六方氮化硼中的电荷极化界面超晶格。
DOI：
10.1038/s41467-020-20667-2
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发表时间：
2021-01-12
影响因子：
16.6
通讯作者：
Fumagalli L
中科院分区：
文献类型：
--
作者：
Woods CR;Ares P;Nevison-Andrews H;Holwill MJ;Fabregas R;Guinea F;Geim AK;Novoselov KS;Walet NR;Fumagalli L
当两维晶体靠近时，它们的相互作用导致电子光谱和晶体结构的重建。这种重建强烈地依赖于晶体之间的扭转角，这已经受到越来越多的关注，由于有趣的电子和光学性质，出现在石墨烯和过渡金属二硫属化物。在这里，我们研究两个绝缘晶体的六方氮化硼堆叠在小扭转角。利用静电力显微镜，我们观察到铁电类畴安排在三角形超晶格具有较大的表面电位。观察是由于界面的弹性变形，导致在平面外的偶极子属于相对的界面表面的硼和氮原子对形成。这产生了双层厚的铁电体，在相邻的域中具有相反极化的（BN和NB）偶极子，与我们的建模一致。这些发现为设计货车范德华异质结构提供了可能性，并为研究莫尔超晶格静电势提供了另一种探针。在这里，由六方氮化硼的扭曲绝缘晶体产生的莫尔超晶格被证明具有类似铁电的特性，这归因于由界面硼和氮原子对形成的应变诱导极化偶极子，这些原子对形成双层厚的铁电畴。
When two-dimensional crystals are brought into close proximity, their interaction results in reconstruction of electronic spectrum and crystal structure. Such reconstruction strongly depends on the twist angle between the crystals, which has received growing attention due to interesting electronic and optical properties that arise in graphene and transitional metal dichalcogenides. Here we study two insulating crystals of hexagonal boron nitride stacked at small twist angle. Using electrostatic force microscopy, we observe ferroelectric-like domains arranged in triangular superlattices with a large surface potential. The observation is attributed to interfacial elastic deformations that result in out-of-plane dipoles formed by pairs of boron and nitrogen atoms belonging to opposite interfacial surfaces. This creates a bilayer-thick ferroelectric with oppositely polarized (BN and NB) dipoles in neighbouring domains, in agreement with our modeling. These findings open up possibilities for designing van der Waals heterostructures and offer an alternative probe to study moiré-superlattice electrostatic potentials. Here, moiré superlattices generated by twisted insulating crystals of hexagonal boron nitride are shown to have a ferroelectric-like character, attributed to strain-induced polarized dipoles formed by pairs of interfacial boron and nitrogen atoms that create bilayer-thick ferroelectric domains.
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DOI：
10.1073/pnas.1309394110
发表时间：
2013-07-09
影响因子：
11.1
作者：
Alden, Jonathan S.;Tsen, Adam W.;McEuen, Paul L.
通讯作者：
McEuen, Paul L.
影响因子：
10.8
作者：
Kretinin, A. V.;Cao, Y.;Gorbachev, R. V.
通讯作者：
Gorbachev, R. V.
影响因子：
38.3
作者：
Dean, C. R.;Young, A. F.;Hone, J.
通讯作者：
Hone, J.
影响因子：
17.1
作者：
Alejandro Castaneda-Uribe, Octavio;Reifenberger, Ronald;Avila, Alba
通讯作者：
Avila, Alba
影响因子：
41.2
作者：
Fumagalli, Laura;Esteban-Ferrer, Daniel;Gomila, Gabriel
通讯作者：
Gomila, Gabriel