Interband scattering across the Lifshitz transition in 
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Sruthi, S; Narang, Deepa S.; Prasad, V.; Bera, Arnab; Kalimuddin, Sk; Watanabe, Kenji; Taniguchi, Takashi; Mondal, Mintu; Bid, Aveek

doi:10.1103/physrevb.106.115421

Cited by 2 publications

(1 citation statement)

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“…5l ), which is consistent with the temperature dependence for the plasmon frequency and Drude weight in WTe 2 13 . This is likely attributed to the temperature-induced Lifshitz transition at about 147–160 K, where the two hole pockets move down in energy with respect to the Fermi surface and eventually disappear, resulting in no hole carriers at higher temperatures 46 , 47 . Further, the polarization dependence of plasmon polaritons of the same devices as those shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Tunable optical topological transitions of plasmon polaritons in WTe2 van der Waals films

et al. 2023

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Naturally existing in-plane hyperbolic polaritons and the associated optical topological transitions, which avoid the nano-structuring to achieve hyperbolicity, can outperform their counterparts in artificial metasurfaces. Such plasmon polaritons are rare, but experimentally revealed recently in WTe2 van der Waals thin films. Different from phonon polaritons, hyperbolic plasmon polaritons originate from the interplay of free carrier Drude response and interband transitions, which promise good intrinsic tunability. However, tunable in-plane hyperbolic plasmon polariton and its optical topological transition of the isofrequency contours to the elliptic topology in a natural material have not been realized. Here we demonstrate the tuning of the optical topological transition through Mo doping and temperature. The optical topological transition energy is tuned over a wide range, with frequencies ranging from 429 cm−1 (23.3 microns) for pure WTe2 to 270 cm−1 (37.0 microns) at the 50% Mo-doping level at 10 K. Moreover, the temperature-induced blueshift of the optical topological transition energy is also revealed, enabling active and reversible tuning. Surprisingly, the localized surface plasmon resonance in skew ribbons shows unusual polarization dependence, accurately manifesting its topology, which renders a reliable means to track the topology with far-field techniques. Our results open an avenue for reconfigurable photonic devices capable of plasmon polariton steering, such as canaling, focusing, and routing, and pave the way for low-symmetry plasmonic nanophotonics based on anisotropic natural materials.

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Section: Resultsmentioning

confidence: 99%