Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, China.
State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Frontiers Science Center for Nano-optoelectronics, and Collaborative Innovation Center of Quantum Matter, Peking University, Beijing, China.
Nature. 2022 Sep;609(7925):46-51. doi: 10.1038/s41586-022-05031-2. Epub 2022 Aug 31.
Superlattices-a periodic stacking of two-dimensional layers of two or more materials-provide a versatile scheme for engineering materials with tailored properties. Here we report an intrinsic heterodimensional superlattice consisting of alternating layers of two-dimensional vanadium disulfide (VS) and a one-dimensional vanadium sulfide (VS) chain array, deposited directly by chemical vapour deposition. This unique superlattice features an unconventional 1T stacking with a monoclinic unit cell of VS/VS layers identified by scanning transmission electron microscopy. An unexpected Hall effect, persisting up to 380 kelvin, is observed when the magnetic field is in-plane, a condition under which the Hall effect usually vanishes. The observation of this effect is supported by theoretical calculations, and can be attributed to an unconventional anomalous Hall effect owing to an out-of-plane Berry curvature induced by an in-plane magnetic field, which is related to the one-dimensional VS chain. Our work expands the conventional understanding of superlattices and will stimulate the synthesis of more extraordinary superstructures.
超晶格——由两种或多种材料的二维层周期性堆叠而成——为工程材料提供了一种通用的设计方案,可以定制具有特定性质的材料。在这里,我们报告了一种由二维二硫化钒(VS)和一维硫化钒(VS)链阵列交替层组成的本征异维超晶格,该超晶格通过化学气相沉积直接沉积而成。这种独特的超晶格具有非常规的 1T 堆叠结构,通过扫描透射电子显微镜确定了 VS/VS 层的单斜单元。当磁场为面内时,观察到一个意想不到的霍尔效应,该效应一直持续到 380 开尔文,而在这种条件下,霍尔效应通常会消失。这一观察结果得到了理论计算的支持,可以归因于由于面内磁场引起的平面外 Berry 曲率引起的非常规反常霍尔效应,这与一维 VS 链有关。我们的工作扩展了对超晶格的传统理解,并将激发更多非凡超结构的合成。