Dielectric catastrophe at the Wigner-Mott transition in a moiré superlattice.
Dielectric catastrophe at the Wigner-Mott transition in a moiré superlattice.
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DOI：
10.1038/s41467-022-32037-1
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发表时间：
2022-07-25
影响因子：
16.6
通讯作者：
中科院分区：
文献类型：
--
作者：
带宽调谐的Wigner-Mott相变是从广义Wigner晶体到费米液体的相互作用驱动的相变。由于这种跃迁通常伴随着磁和电荷序不稳定性，因此仍然不清楚是否存在连续的维格纳-莫特跃迁。在这里，我们展示了带宽调谐的金属-绝缘体过渡在固定分数填充的MoSe 2/WS 2莫尔超晶格。带宽由面外电场控制。的介电响应的光学探测与远程WSe 2传感器层中的2s激子。对于具有大的负介电常数的金属态，激子谱重量可以忽略不计。当从绝缘侧接近过渡时，它连续消失，对应于由过渡附近的临界电荷动力学驱动的发散介电常数或“介电灾难”。我们的研究结果支持了二维三角晶格中连续Wigner-Mott跃迁的假设，并激发了未来对附近奇异量子相的探索。Wigner-Mott绝缘体是由扩展库仑排斥驱动的，而不是Mott绝缘体的就地库仑排斥。在这里，作者观察到一个连续的带宽调谐过渡金属和Wigner-Mott绝缘体之间的MoSe 2/WS 2莫尔超晶格分数晶格填充。
The bandwidth-tuned Wigner-Mott transition is an interaction-driven phase transition from a generalized Wigner crystal to a Fermi liquid. Because the transition is generally accompanied by both magnetic and charge-order instabilities, it remains unclear if a continuous Wigner-Mott transition exists. Here, we demonstrate bandwidth-tuned metal-insulator transitions at fixed fractional fillings of a MoSe2/WS2 moiré superlattice. The bandwidth is controlled by an out-of-plane electric field. The dielectric response is probed optically with the 2s exciton in a remote WSe2 sensor layer. The exciton spectral weight is negligible for the metallic state with a large negative dielectric constant. It continuously vanishes when the transition is approached from the insulating side, corresponding to a diverging dielectric constant or a ‘dielectric catastrophe’ driven by the critical charge dynamics near the transition. Our results support the scenario of continuous Wigner-Mott transitions in two-dimensional triangular lattices and stimulate future explorations of exotic quantum phases in their vicinities. The Wigner-Mott insulator is driven by extended Coulomb repulsion, rather than the on-site Coulomb repulsion of the Mott insulator. Here, the authors observe a continuous bandwidth-tuned transition between a metal and a Wigner-Mott insulator in a MoSe2/WS2 moiré superlattice at fractional lattice filling.
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影响因子：
16.6
作者：
Raja A;Chaves A;Yu J;Arefe G;Hill HM;Rigosi AF;Berkelbach TC;Nagler P;Schüller C;Korn T;Nuckolls C;Hone J;Brus LE;Heinz TF;Reichman DR;Chernikov A
通讯作者：
Chernikov A
影响因子：
8.6
作者：
Aebischer, C;Baeriswyl, D;Noack, RM
通讯作者：
Noack, RM
影响因子：
3.7
作者：
Morales-Duran, Nicolas;MacDonald, Allan H.;Potasz, Pawel
通讯作者：
Potasz, Pawel
影响因子：
64.8
作者：
Regan, Emma C.;Wang, Danqing;Wang, Feng
通讯作者：
Wang, Feng
影响因子：
8.6
作者：
Pan, Haining;Das Sarma, Sankar
通讯作者：
Das Sarma, Sankar