Effect of symmetry breaking on altermagnetism in CrSb and Formation of fragmented nodal curves

Abstract

Phenomena concerning altermagnets have opened up a window for unconventional analysis of the momentum space spin polarization (MSSP) of antiferromagnetic materials. Taking the example of one of the widely investigated altermagnets, CrSb, we explore the underlying mechanisms leading to the formation or breaking of altermagnetism. With the aid of DFT calculation and symmetry analysis, we study the behavior of MSSP in the altermagnetic bands of pristine CrSb, along with a few model structures designed from the pristine one by hypothetical vacancy engineering and interstitial doping. We show that the six-fold rotational symmetry of the pristine CrSb can be reduced to a two-fold rotational symmetry via vacancy and doping engineering. We discover the formation of fragmented nodal curves (FNCs) across the Brillouin zone when in an altermagnetic material when the symmetry is restricted to two-fold rotation. Unlike the typical nodal planes and axes, the location of the FNCs in the momentum space is found to be band-specific. The formation of FNCs is further validated by introducing uniaxial strain to CrSb and by examining the band structure of RbMnPO${}_4$, as they both exhibit a two-fold rotational symmetry responsible for altermagnetism. We observe that, unlike the pristine case, these FNCs have the potential to manifest anomalous Hall conductivities (AHC), while the Néel vector orients along both in-plane and out-of-plane directions. This flexibility of the AHC will pave the way for the application of altermagnets in the futuristic quantum devices.

11 pages, 8 figures, and 2 tables

References in corpus (24)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Altermagnetism: spin-momentum locked phase protected by non-relativistic symmetries
• Broken Kramers' degeneracy in altermagnetic MnTe
• Giant and tunneling magnetoresistance effects from anisotropic and valley-dependent spin-momentum interactions in antiferromagnets
• Altermagnetism: Exploring New Frontiers in Magnetism and Spintronics
• Direct observation of altermagnetic band splitting in CrSb thin films
• Spontaneous anomalous Hall effect arising from an unconventional compensated magnetic phase in a semiconductor
• Large band-splitting in $g$-wave type altermagnet CrSb
• Enumeration and representation theory of spin space groups
• High performance Wannier interpolation of Berry curvature and related quantities: WannierBerri code
• Three-dimensional mapping of the altermagnetic spin splitting in CrSb
• Spin Space Groups: Full Classification and Applications
• Enumeration of spin-space groups: Towards a complete description of symmetries of magnetic orders
• Saturation of the anomalous Hall effect at high magnetic fields in altermagnetic RuO2
• Catalog of Unconventional Magnons in Collinear Magnets
• Anisotropy of the anomalous Hall effect in the altermagnet candidate Mn${}_5$Si${}_3$ films
• Topological Weyl Altermagnetism in CrSb
• Spin-Polarized Antiferromagnetic Spintronics
• Interplay of altermagnetism and pressure in hexagonal and orthorhombic MnTe
• Direction-Dependent Conduction Polarity in Altermagnetic CrSb
• Altermagnetic band splitting in 10 nm epitaxial CrSb thin films
• Dimension- and Facet-Dependent Altermagnetic Biferroics and Ferromagnetic Biferroics and Triferroics in CrSb
• Ultrafast controlling net magnetization in g-wave altermagnets via laser fields
• Unlocking Doping Effects on Altermagnetism in MnTe: Emergence of Quasi-altermagnetism

Cited by in corpus (1)

• Altermagnetism from the viewpoint of chemistry