Emerging new phases in correlated Mott insulator Ca2RuO4

Fuente: arXiv
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Main Authors: Cuono, Giuseppe, Forte, Filomena, Romano, Alfonso, Noce, Canio
Format: Preprint
Published: 2024
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_version_ 1866917847824859136
author Cuono, Giuseppe
Forte, Filomena
Romano, Alfonso
Noce, Canio
author_facet Cuono, Giuseppe
Forte, Filomena
Romano, Alfonso
Noce, Canio
contents The Mott insulator Ca2RuO4 is a paradigmatic example among transition metal oxides, where the interplay of charge, spin, orbital, and lattice degrees of freedom leads to competing quantum phases. In this paper, we focus on and review some key aspects, from the underlying physical framework and its basic properties, to recent theoretical efforts that aim to trigger unconventional quantum ground states, using several external parameters and stimuli. Using first-principle calculations, we demonstrate that Ca2RuO4 shows a spin splitting in the reciprocal space, and identify it as an altermagnetic candidate material. The non relativistic spin-splitting has an orbital selective nature, dictated by the local crystallographic symmetry. Next, we consider two routes that may trigger exotic quantum states. The first one corresponds to transition metal substitution of the 4d4 Ru with isovalent 3d3 ions. This substitutional doping may alter the spin-orbital correlations favoring the emergence of negative thermal expansion. The second route explores fledgling states arising in a nonequilibrium steady state under the influence of an applied electric field. We show that the electric field can directly affect the orbital density, eventually leading to strong orbital fluctuations and the suppression of orbital imbalance, which may, in turn, reduce antiferromagnetism. These aspects suggest possible practical applications, as its unique properties may open up possibilities for augmenting existing technologies, surpassing the limitations of conventional materials.
format Preprint
id arxiv_https___arxiv_org_abs_2411_16472
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Emerging new phases in correlated Mott insulator Ca2RuO4
Cuono, Giuseppe
Forte, Filomena
Romano, Alfonso
Noce, Canio
Strongly Correlated Electrons
The Mott insulator Ca2RuO4 is a paradigmatic example among transition metal oxides, where the interplay of charge, spin, orbital, and lattice degrees of freedom leads to competing quantum phases. In this paper, we focus on and review some key aspects, from the underlying physical framework and its basic properties, to recent theoretical efforts that aim to trigger unconventional quantum ground states, using several external parameters and stimuli. Using first-principle calculations, we demonstrate that Ca2RuO4 shows a spin splitting in the reciprocal space, and identify it as an altermagnetic candidate material. The non relativistic spin-splitting has an orbital selective nature, dictated by the local crystallographic symmetry. Next, we consider two routes that may trigger exotic quantum states. The first one corresponds to transition metal substitution of the 4d4 Ru with isovalent 3d3 ions. This substitutional doping may alter the spin-orbital correlations favoring the emergence of negative thermal expansion. The second route explores fledgling states arising in a nonequilibrium steady state under the influence of an applied electric field. We show that the electric field can directly affect the orbital density, eventually leading to strong orbital fluctuations and the suppression of orbital imbalance, which may, in turn, reduce antiferromagnetism. These aspects suggest possible practical applications, as its unique properties may open up possibilities for augmenting existing technologies, surpassing the limitations of conventional materials.
title Emerging new phases in correlated Mott insulator Ca2RuO4
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2411.16472