Electrical field tuning of magneto-Raman scattering in monolayer graphene

作     者：Xiaonan Shen Caiyu Qiu Bingchen Cao Chunxiao Cong Weihuang Yang Haomin Wang Ting Yu 

作者机构：Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 637371 Singapore Singapore Wenzhou Institute of Biomaterials and Engineering Wenzhou 325001 China Department of Physics Faculty of Science National University of Singapore 117542 Singapore Singapore Graphene Research Center Faculty of Science National University of Singapore 117546 Singapore Singapore 

出 版 物：《Nano Research》 (纳米研究（英文版）)

年 卷 期：2015年第8卷第4期

页      面：1139-1147页

核心收录：

学科分类：081702[工学-化学工艺] 081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070302[理学-分析化学] 0703[理学-化学] 

基　　金：supported by the Singapore National Research Foundation under NRF RF Award MOE Tier 2 

主　　题：monolayer graphene magneto-phononresonance Raman electrical field suspended graphene 

摘      要：In this work, we report the electrical field tuning of magneto-phonon resonance in monolayer graphene under magnetic fields up to 9 T. It is found that the carrier concentration can drastically affect the G （E2g） phonon response to a varying magnetic field through a pronounced magneto-phonon resonance （MPR）. In charge neutral or slightly doped monolayer graphene, both the energy and the line width of the E2g phonon show clear variation with magnetic fields. This is attributed to magneto-phonon resonance between magnetoexcitations and the E2g phonons. In contrast, when the Fermi level of the monolayer graphene is far away from the Dirac point, the G band shows weak magnetic dependence and exhibits a symmetric line-shape. This suggests that the magneto-phonon coupling around 4 T has been switched off due to the Pauli blocking of the inter-Landau level excitations. Moreover, the G band asymmetry caused by Fano resonance between excitonic many-body states and the E2g phonons is observed. This work offers a way to study the magnetoexcitation phonon interaction of materials through magneto-Raman spectroscopy with an external electrical field.