RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 , Japan.
Department of Applied Physics and Quantum-Phase Electronics Centre (QPEC) , The University of Tokyo , Tokyo 113-8656 , Japan.
Nano Lett. 2018 May 9;18(5):3113-3117. doi: 10.1021/acs.nanolett.8b00673. Epub 2018 Apr 9.
Two-dimensional (2D) materials exhibit unusual physical and chemical properties that are attributed to the thinning-induced modification of their electronic band structure. Recently, reduced thickness was found to dramatically impact not only the static electronic structure, but also the dynamic ordering kinetics. The ordering kinetics of first-order phase transitions becomes significantly slowed with decreasing thickness, and metastable supercooled states can be realized by thinning alone. We therefore focus on layered iridium ditelluride (IrTe), a charge-ordering system that is transformed into a superconductor by suppressing its first-order transition. Here, we discovered a persistent superconducting zero-resistance state in mechanically exfoliated IrTe thin flakes. The maximum superconducting critical temperature ( T) was identical to that which is chemically optimized, and the emergent superconductivity was revealed to have a metastable nature. The discovered robust metastable superconductivity suggests that 2D material is a new platform to induce, control, and functionalize metastable electronic states that are inaccessible in bulk crystals.
二维（2D）材料表现出异常的物理和化学性质，这归因于其电子能带结构的减薄诱导修饰。最近发现，厚度的减小不仅显著影响静态电子结构，还影响动态有序动力学。一级相变的动力学显著减慢随着厚度的减小，并且通过减薄本身可以实现亚稳态过冷状态。因此，我们专注于层状碲化铱（IrTe），这是一种通过抑制其一级相变转变为超导体的电荷有序体系。在这里，我们在机械剥落的 IrTe 薄片中发现了持久的超导零电阻状态。最大超导临界温度（T）与化学优化的温度相同，并且揭示出出现的超导性具有亚稳性质。所发现的稳健的亚稳超导性表明，2D 材料是一个新的平台，可以诱导、控制和功能化在体晶体中无法获得的亚稳电子态。
