Modulating Charge Density Wave Order in a 1T-TaS2/Black Phosphorus Heterostructure.
Modulating Charge Density Wave Order in a 1T-TaS2/Black Phosphorus Heterostructure.
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DOI：
10.1021/acs.nanolett.8b04805
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发表时间：
2019-04
期刊：
影响因子：
10.8
通讯作者：
Ziying Wang;L. Chu;Linjun Li;Ming Yang;Junyong Wang;G. Eda;K. Loh
中科院分区：
文献类型：
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作者：
Ziying Wang;L. Chu;Linjun Li;Ming Yang;Junyong Wang;G. Eda;K. Loh
集体电子状态的可控性一直是长期追求的科学和技术目标，并有望开发新设备。本文研究了1 T-TaS_2/BP二维货车德瓦尔斯异质结中电荷密度波（CDW）的调谐。在输运测量中，在BP支撑的1 T-TaS 2纳米片中观察到不寻常的依赖于栅极的电导振荡。扫描隧道显微镜研究表明，在该体系中，近公度（NC）CDW相存活到4.5K，这大大低于NC到公度CDW相的转变温度180 K。采用库仑阻塞模型解释了电导振荡现象，其中NC相的畴壁和畴分别作为一系列量子点阵列和隧穿势垒。密度泛函理论计算表明，一系列的界面相互作用，包括应变和电荷转移，影响CDW的稳定性。我们的工作揭示了通过二维异质结堆叠调整CDW订单，并提供了新的见解CDW相变和滑动机制。
Controllability of collective electron states has been a long-sought scientific and technological goal and promises development of new devices. Herein, we investigate the tuning of charge density wave (CDW) in 1T-TaS2 via a two-dimensional (2D) van der Waals heterostructure of 1T-TaS2/BP. Unusual gate-dependent conductance oscillations were observed in 1T-TaS2 nanoflake supported on BP in transport measurements. Scanning tunneling microscopy study shows that the nearly commensurate (NC) CDW phase survived to 4.5 K in this system, which is substantially lower than the NC to commensurate CDW phase transition temperature of 180 K. A Coulomb blockade model was invoked to explain the conductance oscillations, where the domain walls and domains in NC phase serve as series of quantum dot arrays and tunnelling barriers, respectively. Density functional theory calculations show that a range of interfacial interactions, including strain and charge transfer, influences the CDW stabilities. Our work sheds light on tuning CDW orders via 2D heterostructure stacking and provides new insights on the CDW phase transition and sliding mechanism.