Charge density waves in the graphene sheets of the superconductor CaC6

被引：64

作者：

Rahnejat, K. C. ^{[1
,2
]}

Howard, C. A. ^{[1
,2
]}

Shuttleworth, N. E. ^{[1
,2
]}

Schofield, S. R. ^{[1
,2
]}

Iwaya, K. ^{[3
]}

Hirjibehedin, C. F. ^{[1
,2
,4
]}

Renner, Ch. ^{[5
]}

Aeppli, G. ^{[1
,2
]}

Ellerby, M. ^{[1
,2
]}

机构：

[1] UCL, London Ctr Nanotechnol, London WC1H 0AH, England

[2] UCL, Dept Phys & Astron, London WC1E 6BT, England

[3] Tohoku Univ, Adv Inst Mat Res, World Premier Int WPI Res Ctr, Sendai, Miyagi 9808577, Japan

[4] UCL, Dept Chem, London WC1H 0AJ, England

[5] Univ Geneva, Dept Condensed Matter Phys, CH-1211 Geneva 4, Switzerland

来源：

NATURE COMMUNICATIONS | 2011年 / 2卷

基金：

英国工程与自然科学研究理事会;

关键词：

GRAPHITE-INTERCALATION COMPOUNDS; QUASI-PARTICLE STATES; SURFACE;

D O I：

10.1038/ncomms1574

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：

Graphitic systems have an electronic structure that can be readily manipulated through electrostatic or chemical doping, resulting in a rich variety of electronic ground states. Here we report the first observation and characterization of electronic stripes in the highly electron-doped graphitic superconductor, CaC6, by scanning tunnelling microscopy and spectroscopy. The stripes correspond to a charge density wave with a period three times that of the Ca superlattice. Although the positions of the Ca intercalants are modulated, no displacements of the carbon lattice are detected, indicating that the graphene sheets host the ideal charge density wave. This provides an exceptionally simple material-graphene-as a starting point for understanding the relation between stripes and superconductivity. Furthermore, our experiments suggest a strategy to search for superconductivity in graphene, namely in the vicinity of striped 'Wigner crystal' phases, where some of the electrons crystallize to form a superlattice.

引用

页数：6

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