Massive Dirac Fermions and Hofstadter Butterfly in a van der Waals Heterostructure

被引：1416

作者：

Hunt, B. ^{[1
]}

Sanchez-Yamagishi, J. D. ^{[1
]}

Young, A. F. ^{[1
]}

Yankowitz, M. ^{[2
]}

LeRoy, B. J. ^{[2
]}

Watanabe, K. ^{[3
]}

Taniguchi, T. ^{[3
]}

Moon, P. ^{[4
]}

Koshino, M. ^{[4
]}

Jarillo-Herrero, P. ^{[1
]}

Ashoori, R. C. ^{[1
]}

机构：

[1] MIT, Dept Phys, Cambridge, MA 02139 USA

[2] Univ Arizona, Dept Phys, Tucson, AZ 85721 USA

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

[4] Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan

来源：

SCIENCE | 2013年 / 340卷 / 6139期

基金：

美国国家科学基金会; 日本学术振兴会;

关键词：

HEXAGONAL BORON-NITRIDE; ENERGY-SPECTRUM; BLOCH ELECTRONS; MAGNETIC-FIELD; GRAPHENE; SUPERLATTICES; STATES;

D O I：

10.1126/science.1237240

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：

van der Waals heterostructures constitute a new class of artificial materials formed by stacking atomically thin planar crystals. We demonstrated band structure engineering in a van der Waals heterostructure composed of a monolayer graphene flake coupled to a rotationally aligned hexagonal boron nitride substrate. The spatially varying interlayer atomic registry results in both a local breaking of the carbon sublattice symmetry and a long-range moire superlattice potential in the graphene. In our samples, this interplay between short- and long-wavelength effects resulted in a band structure described by isolated superlattice minibands and an unexpectedly large band gap at charge neutrality. This picture is confirmed by our observation of fractional quantum Hall states at +/- 5/3 filling and features associated with the Hofstadter butterfly at ultrahigh magnetic fields.

引用

页码：1427 / 1430

页数：4

共 32 条

[1] Evidence of Hofstadter's fractal energy spectrum in the quantized Hall conductance [J].