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Charge density waves and degenerate modes in exfoliated monolayer 2H-TaS2.

ABSTRACT: Charge density waves spontaneously breaking lattice symmetry through periodic lattice distortion, and electron-electron and electron-phonon inter-actions, can lead to a new type of electronic band structure. Bulk 2H-TaS2 is an archetypal transition metal dichalcogenide supporting charge density waves with a phase transition at 75?K. Here, it is shown that charge density waves can exist in exfoliated monolayer 2H-TaS2 and the transition temperature can reach 140?K, which is much higher than that in the bulk. The degenerate breathing and wiggle modes of 2H-TaS2 originating from the periodic lattice distortion are probed by optical methods. The results open an avenue to investigating charge density wave phases in two-dimensional transition metal dichalcogenides and will be helpful for understanding and designing devices based on charge density waves.

SUBMITTER: Zhang D

PROVIDER: S-EPMC7467171 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

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Charge density waves and degenerate modes in exfoliated monolayer 2H-TaS2.

Zhang Duan D Wu Yecun Y Su Yu-Hsin YH Hsu Ming-Chien MC Ó Coileáin Cormac C Cho Jiung J Choi Miri M Chun Byong Sun BS Guo Yao Y Chang Ching-Ray CR Wu Han-Chun HC

IUCrJ 20200825 Pt 5

Charge density waves spontaneously breaking lattice symmetry through periodic lattice distortion, and electron-electron and electron-phonon inter-actions, can lead to a new type of electronic band structure. Bulk 2H-TaS2 is an archetypal transition metal dichalcogenide supporting charge density waves with a phase transition at 75 K. Here, it is shown that charge density waves can exist in exfoliated monolayer 2H-TaS2 and the transition temperature can reach 140 K, which is ...[more]

PMID: 32939283

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