Design of a Mott Multiferroic from a Nonmagnetic Polar Metal

Puggioni, Danilo; Giovannetti, Gianluca; Capone, Massimo; Rondinelli, James M.

doi:10.1103/physrevlett.115.087202

Cited by 76 publications

(61 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a result, for the physically relevant values of U and J H LiOsO 3 is indeed in a highly correlated regime, as discussed in Ref. 26. We now discuss how the strong correlations manifest themselves in the optical conductivity and we compare the theoretical results with experiments.…”

Section: Density Functional and Dynamical Mean Fieldmentioning

confidence: 87%

“…The first unambiguous ferroelectric metal emerges therefore as an extremely correlated compound, which could turn into a Mott insulator if the role of the interaction was only slightly stronger [4,26]. We argue that the proximity to such a metal-insulator transition is indeed a key property which favors the existence of polar distortion in a metallic state, suggesting that the poor metal close to Mott localization is not able to fully screen the electric dipoles.…”

Section: Density Functional and Dynamical Mean Fieldmentioning

confidence: 97%

“…A naive estimate of the degree of correlation is simply to compare the non-interacting bandwidth with the onsite Coulomb interaction, which here can be estimated around 2 eV by comparison with similar compounds [26]. As these values might suggest an intermediate degree of correlation, it is important to take into account also the Hund's exchange coupling J H , which, for half-filled multiorbital systems indeed favors the electronic localization, leading to a smaller critical value of U for the MottHubbard transition [27].…”

Section: Density Functional and Dynamical Mean Fieldmentioning

confidence: 99%

See 2 more Smart Citations

Electronic correlations in the ferroelectric metallic state ofLiOsO3

et al. 2016

View full text Add to dashboard Cite

LiOsO3 has been recently identified as the first unambiguous "ferroelectric metal", experimentally realizing a prediction from 1965 by Anderson and Blount. In this work, we investigate the metallic state in LiOsO3 by means of infrared spectroscopy supplemented by Density Functional Theory and Dynamical Mean Field Theory calculations. Our measurements and theoretical calculations clearly show that LiOsO3 is a very bad metal with a small quasiparticle weight, close to a Mott-Hubbard localization transition. The agreement between experiments and theory allows us to ascribe all the relevant features in the optical conductivity to strong electron-electron correlations within the t2g manifold of the osmium atoms. Introduction -Ferroelectric materials display a spontaneous polarization due to an inversion symmetry breaking induced by the macroscopic ordering of local dipole moments. Multiferroic materials are defined by coexistent and coupled magnetic and ferroelectric order. It is a natural expectation that ferroelectric (and consequently multiferroic) ordering can only happen in insulators in order to avoid the metallic charge carriers to screen out the ferroelectric polarization. The existence of "ferroelectric metals" challenging this expectation has been hypothesized in 1965 by Anderson and Blount [1], who have shown that ferroelectricity can occur in a metal as long as the electrons at the Fermi level are decoupled from the ferroelectric distortions. Under these circumstances, the ferroelectric ordering can take place through a second-order transition. In 2013 the first unambiguous realization of this proposal has been reported in LiOsO 3 , where a second-order transition leads to a ferroelectric ionic structure below 140 K while the material remains conducting [2]. This behavior is accompanied by a large residual resistivity which exceeds by two orders of magnitude that of prototypical metals as gold, and by a CurieWeiss like behavior of the magnetic susceptibility in the ordered phase which suggests the presence of almost localized magnetic moments, characteristic precursors of Mott localization [2].

show abstract

Section: Density Functional and Dynamical Mean Fieldmentioning

confidence: 87%

Section: Density Functional and Dynamical Mean Fieldmentioning

confidence: 97%

Section: Density Functional and Dynamical Mean Fieldmentioning

confidence: 99%

See 1 more Smart Citation

Electronic correlations in the ferroelectric metallic state ofLiOsO3

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Polar metals may facilitate the design of materials with controllable metalinsulator transitions and, paradoxically, insulating multiferroics, as shown by recent theoretical predictions on LiOsO 3 /LiNbO 3 superlattices. 16 Highly conductive ferroelectric oxides -those with carrier concentrations close to a metal-insulator transition -are of interest for oxidebased thermoelectrics. 17 The practical applications of polar metals and highly conductive ferroelectrics are largely unexplored but promising avenues for further research.…”

mentioning

confidence: 99%

‘Ferroelectric’ metals reexamined: fundamental mechanisms and design considerations for new materials

2016

View full text Add to dashboard Cite

The recent observation of a ferroelectric-like structural transition in metallic LiOsO3 has generated a flurry of interest in the properties of polar metals. Such materials are thought to be rare because free electrons screen out the long-range electrostatic forces that favor a polar structure with a dipole moment in every unit cell. In this work, we question whether long-range electrostatic forces are always the most important ingredient in driving polar distortions. We use crystal chemical models, in combination with first-principles Density Functional Theory calculations, to explore the mechanisms of inversion-symmetry breaking in LiOsO3 and both insulating and electron-doped ATiO3 perovskites, A = Ba, Sr, Ca. Although electrostatic forces do play a significant role in driving the polar instability of BaTiO3 (which is suppressed under electron doping), the polar phases of CaTiO3 and LiOsO3 emerge through a mechanism driven by local bonding preferences and this mechanism is 'resistant' to the presence of charge carriers. Hence, our results suggest that there is no fundamental incompatibility between metallicity and polar distortions. We use the insights gained from our calculations to suggest design principles for new polar metals and promising avenues for further research.

show abstract

“…30,31 The interplay between SOC and polarity could yield exotic quantum phenomenon in polar ferroelectric-metals. 32,33 Here, we take advantage of the large SOC of Bi and Sb atoms [34][35][36][37] and the ferroelectric polarization of BiSb semiconductor to control the spin-related properties in the present BiSb system.…”

mentioning

confidence: 99%