Giant ferroelectric polarization in a bilayer graphene heterostructure.
Giant ferroelectric polarization in a bilayer graphene heterostructure.
复制标题
DOI：
10.1038/s41467-022-34104-z
复制
发表时间：
2022-10-21
影响因子：
16.6
通讯作者：
中科院分区：
文献类型：
--
作者：
在范德华异质结构界面处，可以重建晶体对称性和电子结构，从而获得优于或不具有母材的物理性能。通过研究由30°扭曲氮化硼片封装的Bernal双层石墨烯moir<s:1>超晶格，我们报道了前所未有的铁电极化，其面电荷密度高达1013 cm−2，远远超出了moir<s:1>带的容量。平移极化~5 pC m−1是人工堆叠范德华晶体设计的最高界面铁电体之一。门特异性铁电性和共同发生的异常筛选通过朗道能级进一步可视化，并且在莫尔带外的费米表面保持鲁棒性，证实了它们对相关电子的独立性。我们还发现，门特有的电阻滞回环可以被另一个门关闭，提供一个额外的控制旋钮。此外，铁电开关可以应用于拓扑谷电流等本征特性。总之，具有强电荷极化增强的门特异性铁电可以鼓励更多的探索来优化和丰富这类新颖的铁电，并促进各种量子现象的铁电开关器件的应用。界面铁电性可能出现在摩尔超晶格中。在这里，作者发现极化电荷远远大于微波微带的容量，并且在带外存在相关的异常屏蔽。
At the interface of van der Waals heterostructures, the crystal symmetry and the electronic structure can be reconstructed, giving rise to physical properties superior to or absent in parent materials. Here by studying a Bernal bilayer graphene moiré superlattice encapsulated by 30°-twisted boron nitride flakes, we report an unprecedented ferroelectric polarization with the areal charge density up to 1013 cm−2, which is far beyond the capacity of a moiré band. The translated polarization ~5 pC m−1 is among the highest interfacial ferroelectrics engineered by artificially stacking van der Waals crystals. The gate-specific ferroelectricity and co-occurring anomalous screening are further visualized via Landau levels, and remain robust for Fermi surfaces outside moiré bands, confirming their independence on correlated electrons. We also find that the gate-specific resistance hysteresis loops could be turned off by the other gate, providing an additional control knob. Furthermore, the ferroelectric switching can be applied to intrinsic properties such as topological valley current. Overall, the gate-specific ferroelectricity with strongly enhanced charge polarization may encourage more explorations to optimize and enrich this novel class of ferroelectricity, and promote device applications for ferroelectric switching of various quantum phenomena. Interfacial ferroelectricity may emerge in moiré superlattices. Here, the authors find that the polarized charge is much larger than the capacity of the moiré miniband and the associated anomalous screening exists outside the band.
登录
查看更多内容
影响因子：
17.1
作者：
Si, Mengwei;Liao, Pai-Ying;Ye, Peide D.
通讯作者：
Ye, Peide D.
在原子厚度的 SnTe 中发现坚固的面内铁电体
影响因子：
56.9
作者：
Chang, Kai;Liu, Junwei;Ji, Shuai-Hua
通讯作者：
Ji, Shuai-Hua
影响因子：
16.6
作者：
de la Barrera SC;Cao Q;Gao Y;Gao Y;Bheemarasetty VS;Yan J;Mandrus DG;Zhu W;Xiao D;Hunt BM
通讯作者：
Hunt BM
影响因子：
16.6
作者：
Liu F;You L;Seyler KL;Li X;Yu P;Lin J;Wang X;Zhou J;Wang H;He H;Pantelides ST;Zhou W;Sharma P;Xu X;Ajayan PM;Wang J;Liu Z
通讯作者：
Liu Z
影响因子：
10.8
作者：
Belianinov, A.;He, Q.;Kalinin, S. V.
通讯作者：
Kalinin, S. V.