Giant valley coherence at room temperature in 3R WS2 with broken inversion symmetry

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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2019-01-01
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en
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Research, Volume 2019
Abstract
Breaking the space-time symmetries in materials can markedly influence their electronic and optical properties. In 3R-stacked transition metal dichalcogenides, the explicitly broken inversion symmetry enables valley-contrasting Berry curvature and quantization of electronic angular momentum, providing an unprecedented platform for valleytronics. Here, we study the valley coherence of 3R WS2 large single-crystal with thicknesses ranging from monolayer to octalayer at room temperature. Our measurements demonstrate that both A and B excitons possess robust and thickness-independent valley coherence. The valley coherence of direct A (B) excitons can reach 0.742 (0.653) with excitation conditions on resonance with it. Such giant and thickness-independent valley coherence of large single-crystal 3R WS2 at room temperature would provide a firm foundation for quantum manipulation of the valley degree of freedom and practical application of valleytronics.
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| openaire: EC/H2020/820423/EU//S2QUIP
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Du, L, Tang, J, Liang, J, Liao, M, Jia, Z, Zhang, Q, Zhao, Y, Yang, R, Shi, D, Gu, L, Xiang, J, Liu, K, Sun, Z & Zhang, G 2019, ' Giant valley coherence at room temperature in 3R WS 2 with broken inversion symmetry ', Research, vol. 2019, 6494565 . https://doi.org/10.34133/2019/6494565