Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/90340
Título: | Measuring valley polarization in two-dimensional materials with second-harmonic spectroscopy |
Autor(es): | Ho, Yi Wei Rosa, Henrique Guimarães Verzhbitskiy, Ivan Rodrigues, Manuel José Lima Ferreira Taniguchi, Takashi Watanabe, Kenji Eda, Goki Pereira, Vitor Manuel Viana-Gomes, Jose Carlos |
Palavras-chave: | Valley polarization Transition metal dichalcogenides 2D materials Second-harmonic generation Graphene |
Data: | 2020 |
Editora: | American Chemical Society |
Revista: | ACS Photonics |
Citação: | Yi Wei Ho, Henrique G. Rosa, Ivan Verzhbitskiy, Manuel J. L. F. Rodrigues, Takashi Taniguchi, Kenji Watanabe, Goki Eda, Vitor M. Pereira, and José C. Viana-Gomes ACS Photonics 2020 7 (4), 925-931 DOI: 10.1021/acsphotonics.0c00174 |
Resumo(s): | A population imbalance at different valleys of an electronic system lowers its effective rotational symmetry. We introduce a technique to measure such imbalance - a valley polarization - that exploits the unique fingerprints of this symmetry reduction in the polarization-dependent second-harmonic generation (SHG). We present the principle and detection scheme in the context of hexagonal two-dimensional crystals, which include graphene-based systems and the family of transition metal dichalcogenides, and provide a direct experimental demonstration using a 2H-MoSe$_{2}$ monolayer at room temperature. We deliberately use the simplest possible setup, where a single pulsed laser beam simultaneously controls the valley imbalance and tracks the SHG process. We further developed a model of the transient population dynamics which analytically describes the valley-induced SHG rotation in very good agreement with the experiment. In addition to providing the first experimental demonstration of the effect, this work establishes a conceptually simple, com-pact and transferable way of measuring instantaneous valley polarization, with direct applicability in the nascent field of valleytronics. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/90340 |
DOI: | 10.1021/acsphotonics.0c00174 |
ISSN: | 2330-4022 |
Versão da editora: | https://doi.org/10.1021/acsphotonics.0c00174 |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | CDF - CEP - Artigos/Papers (with refereeing) |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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ho-et-al-2020-measuring-valley-polarization-in-two-dimensional-materials-with-second-harmonic-spectroscopy.pdf | 1,3 MB | Adobe PDF | Ver/Abrir | |
ho-et-al-2020-measuring-valley-polarization-in-two-dimensional-materials-with-second-harmonic-spectroscopy.pdf | 533,09 kB | Adobe PDF | Ver/Abrir |