Electron-phonon instability in graphene revealed by global and local noise probes

被引：57

作者：

Andersen, Trond I. ^{[1
]}

Dwyer, Bo L. ^{[1
]}

Sanchez-Yamagishi, Javier D. ^{[2
]}

Rodriguez-Nieva, Joaquin F. ^{[1
]}

Agarwal, Kartiek ^{[3
]}

Watanabe, Kenji ^{[4
]}

Taniguchi, Takashi ^{[4
]}

Demler, Eugene A. ^{[1
]}

Kim, Philip ^{[1
,5
]}

Park, Hongkun ^{[1
,6
]}

Lukin, Mikhail D. ^{[1
]}

机构：

[1] Harvard Univ, Dept Phys, Cambridge, MA 02138 USA

[2] Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA

[3] McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada

[4] Natl Inst Mat Sci, Namiki 1-1, Tsukuba, Ibaraki 3050044, Japan

[5] Harvard Univ, John A Paulson Sch Engn & Appl Sci, Cambridge, MA 02138 USA

[6] Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA

来源：

SCIENCE | 2019年 / 364卷 / 6436期

基金：

美国国家科学基金会;

关键词：

AMPLIFICATION; SPIN; SATURATION; TRANSISTOR; GENERATION;

D O I：

10.1126/science.aaw2104

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：

Understanding and controlling nonequilibrium electronic phenomena is an outstanding challenge in science and engineering. By electrically driving ultraclean graphene devices out of equilibrium, we observe an instability that is manifested as substantially enhanced current fluctuations and suppressed conductivity at microwave frequencies. Spatial mapping of the nonequilibrium current fluctuations using nanoscale magnetic field sensors reveals that the fluctuations grow exponentially along the direction of carrier flow. Our observations, including the dependence on density and temperature, are consistently explained by the emergence of an electron-phonon Cerenkov instability at supersonic drift velocities. These results offer the opportunity for tunable terahertz generation and active phononic devices based on two-dimensional materials.

引用

页码：154 / +

页数：45

共 59 条

[1] Magnetic noise spectroscopy as a probe of local electronic correlations in two-dimensional systems [J].