Transverse Peierls Transition

Article Chemistry, Multidisciplinary

Chiral Phonon Diode Effect in Chiral Crystals

Hao Chen et al.

Summary: This study reveals an intrinsic connection between the chiralities of a crystal structure and its phonon excitations, leading to the realization of a chiral phonon diode effect in chiral crystals.

NANO LETTERS (2022)

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Article Materials Science, Multidisciplinary

Chiral phonons entangled with multiple Hall effects and unified convention for pseudoangular momentum in two-dimensional materials

Tiantian Zhang et al.

Summary: Recently, there has been growing interest in a series of two-dimensional nonmagnetic layered materials called XSi2Y4 (where X represents transition metals and Y represents pnictogens) due to their potential applications. Similar to transition-metal dichalcogenides (TMDs), it is proposed that XSi2Y4 can exhibit chiral phonon involved valley-selective optical circular dichroism, which can be entangled with multiple Hall effects. However, comparing such effects between XSi2Y4 and TMDs has been challenging due to the lack of unified conventions for pseudoangular momentum (PAM) in previous studies. In this study, MoSi2As4 and MoS2 are used as examples to establish a unified convention for both phonon PAM and electronic PAM. The similarities and differences in crystal structure, band structures, and valley-selective optical circular dichroism between the two materials are also explored. The results show that in MoSi2As4, the chiral phonon emission/absorption, spin, valley, and transverse Hall current can be modulated by changing the energy or handedness of the incident light, demonstrating better performance than TMDs.

PHYSICAL REVIEW B (2022)

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Article Physics, Multidisciplinary

Chiral phonons and pseudoangular momentum in nonsymmorphic systems

Tiantian Zhang et al.

Summary: In this work, the definition of phonon pseudoangular momentum (PAM) is generalized to nonsymmorphic systems, which show distinct properties compared to symmorphic systems. The phonon PAM can be nonintegers and q dependent in these nonsymmorphic systems. This new definition and discovery can enable the observation of chiral phonons in a wider range of systems and convey information like chirality and angular momentum.

PHYSICAL REVIEW RESEARCH (2022)

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Article Physics, Multidisciplinary

A charge-density-wave topological semimetal

Wujun Shi et al.

Summary: The study demonstrates that (TaSe4)(2)I is a Weyl semimetal with 24 pairs of Weyl nodes at room temperature, and also exhibits an established charge-density wave instability. The charge-density wave in (TaSe4)(2)I couples the bulk Weyl points and opens a bandgap, providing a pathway for exploring the interplay of correlations and topology in a solid-state material.

NATURE PHYSICS (2021)

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Article Physics, Multidisciplinary

Charge density wave and weak Kondo effect in a Dirac semimetal CeSbTe

Peng Li et al.

Summary: Through ARPES and LEED techniques, along with DFT calculations, it was found that CDW is formed in CeSbTe and interacts with the Kondo effect and topological states. The CDW order is driven by electron-phonon coupling, leading to robustness of the CDW order at high temperatures.

SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY (2021)

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Article Physics, Multidisciplinary