TY - JOUR
T1 - Topological Singularity Induced Chiral Kohn Anomaly in a Weyl Semimetal
AU - Nguyen, Thanh
AU - Han, Fei
AU - Andrejevic, Nina
AU - Pablo-Pedro, Ricardo
AU - Apte, Anuj
AU - Tsurimaki, Yoichiro
AU - Ding, Zhiwei
AU - Zhang, Kunyan
AU - Alatas, Ahmet
AU - Alp, Ercan E.
AU - Chi, Songxue
AU - Fernandez-Baca, Jaime
AU - Matsuda, Masaaki
AU - Tennant, David Alan
AU - Zhao, Yang
AU - Xu, Zhijun
AU - Lynn, Jeffrey W.
AU - Huang, Shengxi
AU - Li, Mingda
N1 - Publisher Copyright:
© 2020 American Physical Society.
PY - 2020/6/12
Y1 - 2020/6/12
N2 - The electron-phonon interaction (EPI) is instrumental in a wide variety of phenomena in solid-state physics, such as electrical resistivity in metals, carrier mobility, optical transition, and polaron effects in semiconductors, lifetime of hot carriers, transition temperature in BCS superconductors, and even spin relaxation in diamond nitrogen-vacancy centers for quantum information processing. However, due to the weak EPI strength, most phenomena have focused on electronic properties rather than on phonon properties. One prominent exception is the Kohn anomaly, where phonon softening can emerge when the phonon wave vector nests the Fermi surface of metals. Here we report a new class of Kohn anomaly in a topological Weyl semimetal (WSM), predicted by field-theoretical calculations, and experimentally observed through inelastic X-ray and neutron scattering on WSM tantalum phosphide. Compared to the conventional Kohn anomaly, the Fermi surface in a WSM exhibits multiple topological singularities of Weyl nodes, leading to a distinct nesting condition with chiral selection, a power-law divergence, and non-negligible dynamical effects. Our work brings the concept of the Kohn anomaly into WSMs and sheds light on elucidating the EPI mechanism in emergent topological materials.
AB - The electron-phonon interaction (EPI) is instrumental in a wide variety of phenomena in solid-state physics, such as electrical resistivity in metals, carrier mobility, optical transition, and polaron effects in semiconductors, lifetime of hot carriers, transition temperature in BCS superconductors, and even spin relaxation in diamond nitrogen-vacancy centers for quantum information processing. However, due to the weak EPI strength, most phenomena have focused on electronic properties rather than on phonon properties. One prominent exception is the Kohn anomaly, where phonon softening can emerge when the phonon wave vector nests the Fermi surface of metals. Here we report a new class of Kohn anomaly in a topological Weyl semimetal (WSM), predicted by field-theoretical calculations, and experimentally observed through inelastic X-ray and neutron scattering on WSM tantalum phosphide. Compared to the conventional Kohn anomaly, the Fermi surface in a WSM exhibits multiple topological singularities of Weyl nodes, leading to a distinct nesting condition with chiral selection, a power-law divergence, and non-negligible dynamical effects. Our work brings the concept of the Kohn anomaly into WSMs and sheds light on elucidating the EPI mechanism in emergent topological materials.
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U2 - 10.1103/PhysRevLett.124.236401
DO - 10.1103/PhysRevLett.124.236401
M3 - Article
C2 - 32603171
AN - SCOPUS:85087396003
SN - 0031-9007
VL - 124
JO - Physical review letters
JF - Physical review letters
IS - 23
M1 - 236401
ER -