Continuous Mott transition in semiconductor moire superlattices

被引:262
作者
Li, Tingxin [1 ]
Jiang, Shengwei [2 ]
Li, Lizhong [1 ]
Zhang, Yang [3 ]
Kang, Kaifei [1 ]
Zhu, Jiacheng [1 ]
Watanabe, Kenji [4 ]
Taniguchi, Takashi [4 ]
Chowdhury, Debanjan [2 ]
Fu, Liang [3 ]
Shan, Jie [1 ,2 ,5 ]
Mak, Kin Fai [1 ,2 ,5 ]
机构
[1] Cornell Univ, Sch Appl & Engn Phys, Ithaca, NY 14853 USA
[2] Cornell Univ, Lab Atom & Solid State Phys, Ithaca, NY 14850 USA
[3] MIT, Dept Phys, Cambridge, MA 02139 USA
[4] Natl Inst Mat Sci, Tsukuba, Ibaraki, Japan
[5] Kavli Inst Cornell Nanoscale Sci, Ithaca, NY 14853 USA
基金
日本科学技术振兴机构; 美国国家科学基金会;
关键词
HUBBARD-MODEL; INSULATOR; METAL; COLLOQUIUM; PHYSICS; STATES;
D O I
10.1038/s41586-021-03853-0
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
The evolution of a Landau Fermi liquid into a non-magnetic Mott insulator with increasing electronic interactions is one of the most puzzling quantum phase transitions in physics(1-6). The vicinity of the transition is believed to host exotic states of matter such as quantum spin liquids(4-7), exciton condensates(8) and unconventional superconductivity(1). Semiconductor moire materials realize a highly controllable Hubbard model simulator on a triangular lattice(9-22), providing a unique opportunity to drive a metal-insulator transition (MIT) via continuous tuning of the electronic interactions. Here, by electrically tuning the effective interaction strength in MoTe2/WSe2 moire superlattices, we observe a continuous MIT at a fixed filling of one electron per unit cell. The existence of quantum criticality is supported by the scaling collapse of the resistance, a continuously vanishing charge gap as the critical point is approached from the insulating side, and a diverging quasiparticle effective mass from the metallic side. We also observe a smooth evolution of the magnetic susceptibility across the MIT and no evidence of long-range magnetic order down to similar to 5% of the Curie-Weiss temperature. This signals an abundance of low-energy spinful excitations on the insulating side that is further corroborated by the Pomeranchuk effect observed on the metallic side. Our results are consistent with the universal critical theory of a continuous Mott transition in two dimensions(4,23). The interaction strength in moire superlattices is tuned to drive a continuous metal-to-insulator transition at a fixed electron density.
引用
收藏
页码:350 / +
页数:18
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