Direct ab initio calculation of magnons in altermagnets: Method, spin-space symmetry aspects, and application to MnTe

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F25%3A10503761" target="_blank" >RIV/00216208:11320/25:10503761 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=5UTl7lBq66" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=5UTl7lBq66</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevB.111.184436" target="_blank" >10.1103/PhysRevB.111.184436</a>

Result language

angličtina

Original language name

Direct ab initio calculation of magnons in altermagnets: Method, spin-space symmetry aspects, and application to MnTe

Original language description

We suggest the first method for direct ab initio calculation of adiabatic magnons in complex collinear magnets. The method is based on the density-functional-theory (DFT) calculation under two different constraints: one constraint governs the change of the magnetization with respect to the ground state, and the other is the symmetry constraint responsible for the value of the magnon wave vector. The advantages of the suggested method with respect to the usual approach of mapping of the electron system on the Heisenberg Hamiltonian of interacting magnetic moments are discussed. The performance of the method is demonstrated by the application to an altermagnet MnTe. The altermagnetism introduced as a concept in 2022 is at present an area of highly intensive research. The characteristic feature of altermagnets is the spin splitting of the electron states in reciprocal k space. Among the discovered properties of the altermagnets is the chirality splitting of the magnons in wave vector q space. We suggest an appoach to the study of the symmetry aspects of magnon chirality splitting. We show that both the chirality splitting of the magnons and the altermagnetic spin splitting of the electron states, though very different in their physical nature, have identical patterns in the corresponding wave vector spaces. Since the altermagnetism of MnTe is the consequence of the presence of the Te atoms, adequate attention is devoted to the symmetry analysis and calculation results for the Te moments induced in the magnon states. In the calculations, each magnon is characterized by its own electron band structure. We investigate the transformation of the electron structure in the transition of the material from the collinear ground state to noncollinear magnon states. We show the connection between the properties of magnon band structures and the chirality properties of magnons. In the investigation of the chirality splitting as well as in both the formulation and the application of our method, an important role play the aspects of generalized symmetry based on the application of the spin-space groups. The symmetry framework connects in one coherent picture different parts of the consideration: (i) the generalized translational symmetry of the magnons as a crucial condition for their efficient ab initio calculation, (ii) altermagnetic spin splitting of the electron states in the ground state, and (iii) chirality splitting and band structures of the magnon excitations.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Physical Review B

ISSN

2469-9950

e-ISSN

2469-9969

Volume of the periodical

111

Issue of the periodical within the volume

18

Country of publishing house

US - UNITED STATES

Number of pages

16

Pages from-to

184436

UT code for WoS article

001501169200006

EID of the result in the Scopus database

2-s2.0-105006742160