Iridium double perovskite 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Sr</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>YIrO</mml:mi><mml:mn>6</mml:mn></mml:msub></mml:mrow></mml:math>
: A combined structural and specific heat study

Corredor, L. T.; Aslan-Cansever, G.; Sturza, Mihai; Manna, Kaustuv; Maljuk, A.; Gaß, S.; Dey, Tusharkanti; Wolter, A. U. B.; Kataeva, О. N.; Zimmermann, A.; Geyer, Marcel; Blum, Christian; Wurmehl, S.; Büchner, B.

doi:10.1103/physrevb.95.064418

Cited by 67 publications

(55 citation statements)

References 37 publications

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“…More recently, interest also developed in other transition metal oxides with octahedron or distorted octahedron crystal-field splittings leading to (t 2g ) 4 ions [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. When the Hubbard U and Hund J H couplings are large it is expected that the system develops S = 1 states, while increasing the SOC λ should lead to states with an effective angular momentum zero.…”

Section: Introductionmentioning

confidence: 99%

Density matrix renormalization group study of a three-orbital Hubbard model with spin-orbit coupling in one dimension

et al. 2017

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Using the Density Matrix Renormalization Group technique we study the effect of spin-orbit coupling on a three-orbital Hubbard model in the (t2g) 4 sector and in one dimension. Fixing the Hund coupling to a robust value compatible with some multiorbital materials, we present the phase diagram varying the Hubbard U and spin-orbit coupling λ, at zero temperature. Our results are shown to be qualitatively similar to those recently reported using the Dynamical Mean Field Theory in higher dimensions, providing a robust basis to approximate many-body techniques. Among many results, we observe an interesting transition from an orbital-selective Mott phase to an excitonic insulator with increasing λ at intermediate U . In the strong U coupling limit, we find a nonmagnetic insulator with an effective angular momentum (J ef f ) 2 = 0 near the excitonic phase, smoothly connected to the (J ef f ) 2 = 0 regime. We also provide a list of quasi-one dimensional materials where the physics discussed in this publication could be realized.

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Section: Introductionmentioning

confidence: 99%

Density matrix renormalization group study of a three-orbital Hubbard model with spin-orbit coupling in one dimension

et al. 2017

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“…9 suggested the magnetism in Ba 2 YIrO 6 was due to paramagnetic impurities. In a later study 11 , they identified a Schottky anomaly in the specific heat of Sr 2 YIrO 6 pointing to the conclusion that paramagnetic impurities are responsible for the observed Curie susceptibilities without the onset of long range magnetic order. In this study, we pursue this line of reasoning and examine the magnetic properties of three types of Ba 2 YIrO 6 single crystals with different heat treatments.…”

Section: 10mentioning

confidence: 99%

Magnetism out of antisite disorder in the J=0 compound Ba2YIrO6

et al. 2017

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We systematically investigate the magnetic properties and local structure of Ba2YIrO6 to demonstrate that Y and Ir lattice defects in the form of antiphase boundary or clusters of antisite disorder affect the magnetism observed in this d 4 compound. We compare the magnetic properties and atomic imaging of (1) a slow cooled crystal, (2) a crystal quenched from 900• C after growth, and (3) a crystal grown using a faster cooling rate than the slow cooled one. Atomic imaging by scanning transmission electron microscopy (STEM) shows that quenching from 900• C introduces antiphase boundary to the crystals, and a faster cooling rate during crystal growth leads to clusters of Y and Ir antisite disorder. STEM study suggests the antiphase boundary region is Ir-rich with a composition of Ba2(Y1−xIrx)IrO6. The magnetic measurements show that Ba2YIrO6 crystals with clusters of antisite defects have a larger effective moment and a larger saturation moment than the slow-cooled crystals. Quenched crystals with Ir-rich antiphase boundary shows a slightly suppressed saturation moment than the slow cooled crystals, and this seems to suggest that antiphase boundary is detrimental to the moment formation. Our DFT calculations suggest magnetic condensation is unlikely as the energy to be gained from superexchange is small compared to the spin-orbit gap. However, once Y is replaced by Ir in the antisite disordered region, the picture of local non-magnetic singlets breaks down and magnetism can be induced. This is because of (a) enhanced interactions due to increased overlap of orbitals between sites, and, (b) increased number of orbitals mediating the interactions. Our work highlights the importance of lattice defects in understanding the experimentally observed magnetism in Ba2YIrO6 and other J = 0 systems.

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“…Ba 2 YIrO 6 is a d 4 system whose ground state is experimentally not completely resolved [43,44]. According to the realistic parameter values in Ba 2 YIrO 6 as given in Table SV in the supplementary materials (Ref.…”

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confidence: 99%

J Freezing and Hund’s Rules in Spin-Orbit-Coupled Multiorbital Hubbard Models

et al. 2017

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We investigate the phase diagram of the spin-orbit-coupled three orbital Hubbard model at arbitrary filling by means of dynamical mean-field theory combined with continuous-time quantum Monte Carlo. We find that the spin-freezing crossover occurring in the metallic phase of the nonrelativistic multiorbital Hubbard model can be generalized to a J-freezing crossover, with J = L+S, in the spin-orbit-coupled case. In the J-frozen regime the correlated electrons exhibit a non-trivial flavor selectivity and energy dependence. Furthermore, in the regions near n = 2 and n = 4 the metallic states are qualitatively different from each other, which reflects the atomic Hund's third rule. Finally, we explore the appearance of magnetic order from exciton condensation at n = 4 and discuss the relevance of our results for real materials.PACS numbers: 71.10. Hf, 71.15.Rf, 71.30.+h, 75.25.Dk Introduction. In 4d and 5d transition metal oxides the interplay and competition between kinetic energy, spinorbit coupling (SOC) and correlation effects results in several interesting phenomena, such as spin-orbit assisted Mott transitions [1][2][3][4][5][6], unconventional superconductivity [9, 10], topological phases [11], exciton condensation [10, 12,13], or exotic magnetic orders [14,15]. Transition metal oxides involving 4d and 5d electrons show diverse structures like the Ruddlesden-Popper series [1, 9], double perovskite, [14][15][16] two-dimensional honeycomb geometry [3][4][5][6][7][8] or pyrochlore lattices [17]. In an octahedral environment, as in most of the 4d and 5d materials mentioned above, the five d orbitals are split into low energy t 2g and higher energy e g levels. The SOC further splits the low energy t 2g levels into a so-called j = 1/2 doublet and j = 3/2 quadruplet. The energy separation between the j = 1/2 and j = 3/2 bands is proportional to the strength of the SOC. Existing ab-initio density functional theory calculations [17,18] suggest that in some materials a multiorbital description including both the j = 1/2 and j = 3/2 subbands should be considered.Most theoretical studies of 4d and 5d systems have focused on material-specific models with fixed electronic filling. Here we follow a different strategy and explore the possible states that emerge from a multiband Hubbard model with spin-orbit coupling at arbitrary filling. This allows us to investigate unexplored regions in parameter space which may exhibit interesting phenomena. Specifically, by performing a systematic analysis of the local J moment susceptibility (J = L + S) as a function of Coulomb repulsion U , Hund's coupling J H , spin-orbit coupling λ and filling n, we identify Mott-Hubbard insulating phases and complex metallic states. We find a J-freezing crossover between a Fermi liquid (FL) and a non-Fermi liquid (NFL) phase where the latter shows a distinct flavor selectivity that originates from the SOC. In addition, we observe a strong asymmetry in the metallic phase between filling n = 2 and n = 4 with properties reminiscent of the atomic Hund'...

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Iridium double perovskite Sr2YIrO6 : A combined structural and specific heat study

Cited by 67 publications

References 37 publications

Density matrix renormalization group study of a three-orbital Hubbard model with spin-orbit coupling in one dimension

Density matrix renormalization group study of a three-orbital Hubbard model with spin-orbit coupling in one dimension

Magnetism out of antisite disorder in the J=0 compound Ba2YIrO6

J Freezing and Hund’s Rules in Spin-Orbit-Coupled Multiorbital Hubbard Models

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