Highly anisotropic collective modes of altermagnetic superconductors with Bogoliubov Fermi surfaces
Abstract
We investigate collective modes in charge-neutral altermagnetic superconductors with d-wave spin-split bands, focusing on the impact of emergent Bogoliubov Fermi surfaces. In the absence of a magnetic field, the BCS state supports collective modes that inherit the underlying d-wave symmetry, resulting in pronounced momentum-space anisotropy. The broken time-reversal symmetry further couples these modes to spin-density fluctuations, allowing their signatures to emerge in the spin dynamical structure factor. Upon applying a magnetic field, Bogoliubov Fermi surfaces emerge and qualitatively reshape the collective-mode dynamics through gapless particle-hole excitations and strongly anisotropic Landau damping. The damping is strongest along the momentum-space diagonal, where it can suppress the low-energy phonon mode at small momenta. Remarkably, the suppressed phonon is accompanied by the emergence of an in-gap structure in the Higgs mode and an associated pronounced enhancement of the spin response. These results establish Bogoliubov Fermi surfaces as a mechanism for generating highly anisotropic collective-mode dynamics and identify spin response as a sensitive probe of in-gap Higgs excitations in altermagnetic superconductors.
Related
- Thermal Responses of Spin Density and Spin Current Induced by Bogoliubov Fermi Surfaces in Proximity Superconductors
- Anomalous Superfluid Response in Altermagnetic Superconductors
- Chiral superconductors from parent states with nonuniform Berry curvature: Momentum-space vortices, Bogoliubov-de Gennes topology, and thermal Hall conductivity
- Secondary Collective Excitations in Intermediate to Strong-Coupling Superconductors
- Rotation and Anisotropic Scaling in Axionic Holographic Superconductors: AdS4 versus Lifshitz5
BibTeX
@misc{zhao2026highly,
title = {{Highly anisotropic collective modes of altermagnetic superconductors with Bogoliubov Fermi surfaces}},
author = {Huaisong Zhao and Peng Zou and Xia-Ji Liu and Hui Hu},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.01011},
eprint = {2610.01011},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.01011},
}
RIS
TY - UNPB
TI - Highly anisotropic collective modes of altermagnetic superconductors with Bogoliubov Fermi surfaces
AU - Huaisong Zhao
AU - Peng Zou
AU - Xia-Ji Liu
AU - Hui Hu
PY - 2026
DA - 2026/10/01
PB - arXiv
DO - 10.48550/arxiv.2610.01011
UR - https://arxiv.org/abs/2610.01011
AB - We investigate collective modes in charge-neutral altermagnetic superconductors with d-wave spin-split bands, focusing on the impact of emergent Bogoliubov Fermi surfaces. In the absence of a magnetic field, the BCS state supports collective modes that inherit the underlying d-wave symmetry, resulting in pronounced momentum-space anisotropy. The broken time-reversal symmetry further couples these modes to spin-density fluctuations, allowing their signatures to emerge in the spin dynamical structure factor. Upon applying a magnetic field, Bogoliubov Fermi surfaces emerge and qualitatively reshape the collective-mode dynamics through gapless particle-hole excitations and strongly anisotropic Landau damping. The damping is strongest along the momentum-space diagonal, where it can suppress the low-energy phonon mode at small momenta. Remarkably, the suppressed phonon is accompanied by the emergence of an in-gap structure in the Higgs mode and an associated pronounced enhancement of the spin response. These results establish Bogoliubov Fermi surfaces as a mechanism for generating highly anisotropic collective-mode dynamics and identify spin response as a sensitive probe of in-gap Higgs excitations in altermagnetic superconductors.
ER -