Coordination Funds

二维（2D）材料是只有一个或很少原子厚度的晶体。在这类材料中最突出的代表石墨烯被发现之后，许多其他二维晶体也被发现。它们经常表现出在三维固体中没有对应的有趣特性。此外，二维晶体的明确堆叠可以导致物质的新状态，即使单个层仅受范德瓦尔斯（vdW）相互作用的束缚很弱。2018年发表的最令人印象深刻的例子是，当两层石墨烯以约1.1度的“魔角”扭曲时，将两层石墨烯转变为超导体。由于对二维材料的大量研究，这种微妙的结构操纵成为可能，为研究所谓的邻近效应所导致的相变打开了大门。例如，已经观察到莫特绝缘体和非常规超导态之间的相变到二维铁磁相或半导体-金属相变。此外，vdW异质结构具有丰富的光学和光电子特性，如层间激子和trions。具有不同性质的二维晶体的结合，例如二维超导体和二维拓扑绝缘体，可以为诸如马约拉纳费米子之类的奇异物理现象打开大门。优先项目2244“二维材料：vdW[异质]结构的物理学”的目标是结合德国科学界的研究努力和专业知识，解决关于堆叠二维材料的许多开放的基本问题。PP 2244有以下三个目标：目标1：研究层间相互作用对二维vdW材料的电子和输运性质的影响。目的2：研究二维vdW材料层间相互作用导致的光学性质。目的3：研究导致二维vdW材料中奇异效应的集体和相关现象。为了确保紧密合作，PP 2244由一个协调办公室陪同。该办公室将负责组织博士生和博士后暑期学校、培训活动、性别平等活动和为所有成员和准成员举办的科学研讨会。此外，还提供了参与项目之间的博士生交流计划和青年科学家的启动资金。PP 2244的科学工作由一个指导委员会陪同。

Two-dimensional (2D) materials are crystals with a thickness of only one or very few atoms. After the discovery of graphene, the most prominent representative of this class of materials, many other 2D crystals have been identified. They often exhibit intriguing properties that have no counterpart in three-dimensional solids. Furthermore, well-defined stacking of 2D crystals can lead to new states of matter, even when the individual layers are only weakly bound by van der Waals (vdW) interactions. The most impressive example published in 2018 is the transformation of bilayer graphene into a superconductor when the layers are twisted by a "magic angle" of about 1.1 degrees. Such delicate structural manipulation has become possible thanks to massive research efforts in 2D materials, opening the door to the study of phase transitions forced by the so-called proximity effect. For example, phase transitions between a Mott insulator and an unconventional superconducting state to a 2D ferromagnetic phase or semiconductor-metal transitions have been observed. In addition, vdW heterostructures offer rich optical and optoelectronic properties, such as interlayer excitons and trions. The combination of 2D crystals with different properties, e.g., a 2D superconductor and a 2D topological insulator, can open the door to exotic physical phenomena such as Majorana fermions. The goal of Priority Program 2244 "2D Materials: Physics of vdW [Hetero]Structures" is to combine research efforts and expertise in the German scientific community to address the many open fundamental questions about stacked 2D materials. PP 2244 has the following three goals: Aim 1: Investigate the effects of interlayer interactions on electronic and transport properties in 2D vdW materials. Aim 2: Investigate the optical properties resulting from interlayer interactions in 2D vdW materials. Aim 3: Investigate collective and correlated phenomena leading to exotic effects in 2D vdW materials. To ensure a close collaboration, PP 2244 is accompanied by a coordination office. This office will take care of the organization of summer schools for PhD students and postdocs, training events, gender equality activities and scientific workshops for all members and associated members of the focus. Furthermore, a program for doctoral student exchange between the participating projects as well as start-up funding for young scientists is offered. The scientific work of PP 2244 is accompanied by a steering committee.