Non-Stoichiometry Effects on the Extreme Magnetoresistance in Weyl Semimetal WTe2

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2018,（9）
• 页码范围: 57-61
• 页数: 5页
• 语种: 英文
• DOI: 10.1088/0256-307X/35/9/097101

摘要

Non-stoichiometry effect on the extreme magnetoresistance is systematically investigated for the Weyl semimetal WTe2.Magnetoresistance and Hall resistivity are measured for the as-grown samples with a slight difference in Te vacancies and the annealed samples with increased Te vacancies.The fits to a two-band model show that the magnetoresistance is strongly dependent on the residual resistivity ratio (i.e.,the degree of non-stoichiometry),which is eventually understood in terms of electron doping that not only breaks the balance between electron-type and hole-type carrier densities,but also reduces the average carrier mobility.Thus the compensation effect and ultrahigh mobility are probably the main driving force of the extreme magnetoresistance in WTe2.