Observation of fractional Chern insulators in a van der Waals heterostructure

被引：214

作者：

Spanton, Eric M. ^{[1
]}

Zibrov, Alexander A. ^{[2
]}

Zhou, Haoxin ^{[2
]}

Taniguchi, Takashi ^{[3
]}

Watanabe, Kenji ^{[3
]}

Zaletel, Michael P. ^{[4
]}

Young, Andrea F. ^{[2
]}

机构：

[1] Univ Calif Santa Barbara, Calif Nanosyst Inst, Santa Barbara, CA 93106 USA

[2] Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA

[3] Natl Inst Mat Sci, Adv Mat Lab, Tsukuba, Ibaraki 3050044, Japan

[4] Princeton Univ, Dept Phys, Princeton, NJ 08544 USA

来源：

SCIENCE | 2018年 / 360卷 / 6384期

基金：

日本学术振兴会;

关键词：

GRAPHENE SUPERLATTICES; DIRAC FERMIONS; LANDAU-LEVEL; HALL; REALIZATION; MODEL;

D O I：

10.1126/science.aan8458

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：

Topologically ordered phases are characterized by long-range quantum entanglement and fractional statistics rather than by symmetry breaking. First observed in a fractionally filled continuum Landau level, topological order has since been proposed to arise more generally at fractional fillings of topologically nontrivial Chern bands. Here we report the observation of gapped states at fractional fillings of Harper-Hofstadter bands arising from the interplay of a magnetic field and a superlattice potential in a bilayer graphene-hexagonal boron nitride heterostructure. We observed phases at fractional filling of bands with Chern indices C = -1, +/- 2, and +/- 3. Some of these phases, in C = -1 and C = 2 bands, are characterized by fractional Hall conductance-that is, they are known as fractional Chern insulators and constitute an example of topological order beyond Landau levels.

引用

页码：62 / 66

页数：5

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