Gate Tuning of Electronic Phase Transitions in Two-Dimensional NbSe2
Gate Tuning of Electronic Phase Transitions in Two-Dimensional NbSe2
复制标题
DOI：
10.1103/physrevlett.117.106801
复制
发表时间：
2016-08-29
影响因子：
8.6
通讯作者：
Mak, Kin Fai
中科院分区：
文献类型：
--
作者：
Xi, Xiaoxiang;Berger, Helmuth;Mak, Kin Fai
最近的实验进展在原子薄的过渡金属二硫属化物（TMD）金属已经揭示了一系列有趣的现象，包括电荷密度波（CDW）秩序和超导性的共存下到单层极限。二维（2D）TMD金属的原子厚度也开辟了通过静电门控控制这些电子相变的可能性。在这里，我们展示了可逆的超导电性和CDW秩序在模型2D TMD金属NbSe 2的离子液体门。超导转变温度的变化高达50%左右。通过增加（降低）2D NbSe 2中载流子密度，可以增强（减弱）超导性和CDW有序性。这些相变的掺杂依赖性可以被理解为驱动由栅极调制的载流子密度和费米表面附近的电子态密度引起的变化的电子-声子耦合强度。
Recent experimental advances in atomically thin transition metal dichalcogenide (TMD) metals have unveiled a range of interesting phenomena including the coexistence of charge-density-wave (CDW) order and superconductivity down to the monolayer limit. The atomic thickness of two-dimensional (2D) TMD metals also opens up the possibility for control of these electronic phase transitions by electrostatic gating. Here, we demonstrate reversible tuning of superconductivity and CDW order in model 2D TMD metal NbSe2 by an ionic liquid gate. A variation up to similar to 50% in the superconducting transition temperature has been observed. Both superconductivity and CDW order can be strengthened (weakened) by increasing (reducing) the carrier density in 2D NbSe2. The doping dependence of these phase transitions can be understood as driven by a varying electron-phonon coupling strength induced by the gate-modulated carrier density and the electronic density of states near the Fermi surface.