Valley Zeeman Splitting and Valley Polarization of Neutral and Charged Excitons in Monolayer MoTe2 at High Magnetic Fields

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• 作者：Ashish Arora ; Robert Schmidt ; Robert Schneider ; Maciej R. Molas ; Ivan Breslavetz ; Marek Potemski ; Rudolf Bratschitsch
• 刊名：Nano Letters
• 出版年：2016
• 出版时间：June 8, 2016
• 年：2016
• 卷：16
• 期：6
• 页码：3624-3629
• 全文大小：430K
• 年卷期：0
• ISSN：1530-6992

文摘

Semiconducting transition metal dichalcogenides (TMDCs) give rise to interesting new phenomena in external magnetic fields, such as valley Zeeman splitting and magnetic-field-induced valley polarization. These effects have been reported for monolayers (MLs) of the transition metal diselenides MoSe₂ and WSe₂ and, more recently, for disulfides MoS₂ and WS₂. Here, we present helicity-resolved magneto-photoluminescence and magneto-reflectance contrast measurements for MLs of the telluride member of the semiconducting TMDCs, 2H-MoTe₂, in magnetic fields up to 29 T in Faraday geometry. Well-resolved valley Zeeman splittings for the neutral A and B excitons (X_A⁰ and X_B⁰) and the charged exciton X^± are observed with effective g-factors of −4.6 ± 0.2, – 3.8 ± 0.6, and −4.5 ± 0.3, respectively. The magnetic field induced valley polarization of X_A⁰ and X^± reaches 78% and 36%, respectively, at a magnetic field of 29 T.