Fragile altermagnetism and orbital disorder in Mott insulator LaTiO$_3$

Fuente: arXiv
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Autori principali: Maznichenko, I. V., Ernst, A., Maryenko, D., Dugaev, V. K., Sherman, E. Ya., Buczek, P., Parkin, S. S. P., Ostanin, S.
Natura: Preprint
Pubblicazione: 2024
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author Maznichenko, I. V.
Ernst, A.
Maryenko, D.
Dugaev, V. K.
Sherman, E. Ya.
Buczek, P.
Parkin, S. S. P.
Ostanin, S.
author_facet Maznichenko, I. V.
Ernst, A.
Maryenko, D.
Dugaev, V. K.
Sherman, E. Ya.
Buczek, P.
Parkin, S. S. P.
Ostanin, S.
contents Based on ab initio calculations, we demonstrate that a Mott insulator LaTiO$_3$ (LTO), not inspected previously as an altermagnetic material, shows the characteristic features of altermagnets, i.e., (i) fully compensated antiferromagnetism and (ii) $\mathbf{k}$-dependent spin-split electron bands in the absence of spin-orbit coupling. The altermagnetic ground state of LTO is protected by the crystal symmetry and specifically ordered $d$-orbitals of Ti ions with the orbital momentum $l=2.$ The altermagnetism occurs when sites of Ti pair in the unit cell are occupied by single electrons with $m=-1,s_{z}=+1/2$ and $m=+1,s_{z}=-1/2$ per site, with $m$ and $s_{z}-$ being the $z-$ component of the orbital momentum and spin, respectively. By further simulating orbital disorder within the Green's function method, we disclose its damaging character on the spin splitting and the resulting altermagnetism. When the single-electron spin-polarized state at each Ti site is contributed almost equally by two or three $t_{2g}$ orbitals, LTO becomes antiferromagnetic. The effect of the spin-orbit coupling, which can cause orbital disorder and suppress altermagnetism, is discussed.
format Preprint
id arxiv_https___arxiv_org_abs_2411_00583
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Fragile altermagnetism and orbital disorder in Mott insulator LaTiO$_3$
Maznichenko, I. V.
Ernst, A.
Maryenko, D.
Dugaev, V. K.
Sherman, E. Ya.
Buczek, P.
Parkin, S. S. P.
Ostanin, S.
Materials Science
Strongly Correlated Electrons
Based on ab initio calculations, we demonstrate that a Mott insulator LaTiO$_3$ (LTO), not inspected previously as an altermagnetic material, shows the characteristic features of altermagnets, i.e., (i) fully compensated antiferromagnetism and (ii) $\mathbf{k}$-dependent spin-split electron bands in the absence of spin-orbit coupling. The altermagnetic ground state of LTO is protected by the crystal symmetry and specifically ordered $d$-orbitals of Ti ions with the orbital momentum $l=2.$ The altermagnetism occurs when sites of Ti pair in the unit cell are occupied by single electrons with $m=-1,s_{z}=+1/2$ and $m=+1,s_{z}=-1/2$ per site, with $m$ and $s_{z}-$ being the $z-$ component of the orbital momentum and spin, respectively. By further simulating orbital disorder within the Green's function method, we disclose its damaging character on the spin splitting and the resulting altermagnetism. When the single-electron spin-polarized state at each Ti site is contributed almost equally by two or three $t_{2g}$ orbitals, LTO becomes antiferromagnetic. The effect of the spin-orbit coupling, which can cause orbital disorder and suppress altermagnetism, is discussed.
title Fragile altermagnetism and orbital disorder in Mott insulator LaTiO$_3$
topic Materials Science
Strongly Correlated Electrons
url https://arxiv.org/abs/2411.00583