Electron and hole doping in the relativistic Mott insulator 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi mathvariant="bold">Sr</mml:mi><mml:mn mathvariant="bold">2</mml:mn></mml:msub><mml:msub><mml:mi mathvariant="bold">IrO</mml:mi><mml:mn mathvariant="bold">4</mml:mn></mml:msub></mml:mrow></mml:math>
: A first-principles study using band unfolding technique

Liu, Peitao; Reticcioli, Michele; Kim, Bongjae; Continenza, A.; Kresse, Georg; Sarma, D. D.; Chen, Xing-Qiu; Franchini, Cesare

doi:10.1103/physrevb.94.195145

Cited by 31 publications

(33 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This observation was attributed to the reduction of the on-site Coulomb repulsion U . However, the first-principles calculation study pointed out that U did not change noticeably at low dopings and could only be fully suppressed upon 80% electron doping 34 . Another ARPES study showed that the J eff = 1/2 bands were consistently separated upon electron doping.…”

Section: Resultsmentioning

confidence: 94%

Infrared probe of pseudogap in electron-doped Sr2IrO4

Seo

Ahn

Song

et al. 2017

Sci Rep

View full text Add to dashboard Cite

We report on infrared spectroscopy experiments on the electronic response in (Sr1−xLax)2IrO4 (x = 0, 0.021, and 0.067). Our data show that electron doping induced by La substitution leads to an insulator-to-metal transition. The evolution of the electronic structure across the transition reveals the robustness of the strong electronic correlations against the electron doping. The conductivity data of the metallic compound show the signature of the pseudogap that bears close similarity to the analogous studies of the pseudogap in the underdoped cuprates. While the low energy conductivity of the metallic compound is barely frequency dependent, the formation of the pseudogap is revealed by the gradual suppression of the featureless conductivity below a threshold frequency of about 17 meV. The threshold structure develops below about 100 K which is in the vicinity of the onset of the short-range antiferromagnetic order. Our results demonstrate that the electronic correlations play a crucial role in the anomalous charge dynamics in the (Sr1−xLax)2IrO4 system.

show abstract

Section: Resultsmentioning

confidence: 94%

Infrared probe of pseudogap in electron-doped Sr2IrO4

Seo

Ahn

Song

et al. 2017

Sci Rep

View full text Add to dashboard Cite

show abstract

“…This is contrary to the electrondoped system, where we observed the emergence of an in-gap state whose momentum distribution is different from UHB. This electron-hole asymmetry in the emergence of an in-gap state upon carrier doping has been reproduced by a first principles study [29], except for the existence of an anisotropic gap [30] and a remnant Fermi surface. In the lightly hole-doped sample of Sr 2 Ir 1−x Rh x O 4 , x = 0.04, LHB lies just below E F with energy gaps in the entire k region and with an anisotropy similar to a higher hole doping.…”

mentioning

confidence: 92%

Evolution of the remnant Fermi-surface state in the lightly doped correlated spin-orbit insulator Sr2−xLaxIrO4

et al. 2017

View full text Add to dashboard Cite

The electronic structure of the lightly electron-doped correlated spin-orbit insulator Sr 2 IrO 4 has been studied by angle-resolved photoelectron spectroscopy. We have observed the coexistence of a lower Hubbard band and an in-gap band; the momentum dependence of the latter traces that of the band calculations without on-site Coulomb repulsion. The in-gap state remained anisotropically gapped in all observed momentum areas, forming a remnant Fermi-surface state, evolving towards the Fermi energy by carrier doping. These experimental results show a striking similarity with those observed in deeply underdoped cuprates, suggesting the common nature of the nodal liquid states observed in both compounds. DOI: 10.1103/PhysRevB.96.041106 Unconventional physics of superconductivity near the metal-insulator transition in strongly correlated Mott insulators has been one of the major themes in a variety of systems, such as cuprates, iron-based compounds, heavyelectron systems, and organic materials [1]. Recently, much attention has been given to 5d-electron systems in which the magnitude of spin-orbit coupling is comparable to the transfer-integral and Coulomb repulsion energies, and this interplay may produce possible novel phases. Sr 2 IrO 4 is a good example of such a system for which the electronic states can be well described by considering spin-orbit coupling as well as Coulomb repulsion energy U [2,3].Sr 2 IrO 4 is an antiferromagnetic insulator with T N = 240 K, and is isostructural to one of the parent compounds of cuprate superconductors, namely, La 2 CuO 4 [4]. Similar to the cuprates, the electronic structure is highly two dimensional, as revealed by angle-resolved photoelectron spectroscopy (ARPES) [5,6]. Unlike cuprates, to date, Sr 2 IrO 4 has not shown superconductivity, although a possible emergence of superconductivity in this system has been theoretically predicted by carrier doping [7][8][9][10]. On the other hand, a d-wave gapped state and Fermi arc behavior have been observed in both the bulk [11] and surface [12][13][14] electronic structures of doped Sr 2 IrO 4 , similar to the cuprates. Such a similarity is puzzling and raises several questions, but this is merely due to the lack of momentum-resolved data in a wide range of doping, especially in the deeply underdoped regime. This is indeed crucial to explore if this anisotropic gap has the same origin as the pseudogap in cuprate superconductors and if the gap is related to superconductivity.To address these unsettled issues, we have studied how this d-wave gapped state evolves by doping in lightly doped Sr 2−x La x IrO 4 (x = 0, 0.04, 0.08) using ARPES. We have observed a dispersive in-gap state that evolves by carrier doping and coexists with the lower Hubbard band (LHB) seen (Fig. S1).ARPES experiments were performed at the 1-squared beamline of BESSY II, using a Scienta-Omicron R8000 analyzer. Circularly polarized light with hν = 100 eV was used to excite the photoelectrons. Clean surfaces for measurements were obtained by in situ cleaving ...

show abstract

“…Assuming λ SOC and Δ c are sufficiently large compared to the relevant bandwidths when Sr 2 IrO 4 crystalizes, a single J eff ¼ 1=2 band is half filled and can be driven by a moderate local Coulomb repulsion U to an AFM Mott insulating state [1,2,7]. The nature of the spin-orbit entangled insulating state has been studied using the localized picture based on the J eff ¼ 1=2 pseudospin anisotropic Heisenberg model [7][8][9][10][11], the three-orbital Hubbard model for the t 2g electrons with SOC [12][13][14][15], and the microscopic correlated density functional theory such as the LDA þ U and GGA þ U [1,[16][17][18]. Moreover, carrier doping the AFM insulating state was proposed to potentially realize a 5d t 2g -electron analog of the 3d e g -electron high-T c cuprate superconductors [8,12,13,19,20].…”

mentioning

confidence: 99%

Correlation Effects and Hidden Spin-Orbit Entangled Electronic Order in Parent and Electron-Doped Iridates Sr2IrO4

Zhou¹,

Jiang²,

Chen³

et al. 2017

Phys. Rev. X

View full text Add to dashboard Cite

Analogs of the high-T c cuprates have been long sought after in transition metal oxides. Because of the strong spin-orbit coupling, the 5d perovskite iridates Sr 2 IrO 4 exhibit a low-energy electronic structure remarkably similar to the cuprates. Whether a superconducting state exists as in the cuprates requires understanding the correlated spin-orbit entangled electronic states. Recent experiments discovered hidden order in the parent and electron-doped iridates, some with striking analogies to the cuprates, including Fermi surface pockets, Fermi arcs, and pseudogap. Here, we study the correlation and disorder effects in a five-orbital model derived from the band theory. We find that the experimental observations are consistent with a d-wave spin-orbit density wave order that breaks the symmetry of a joint twofold spin-orbital rotation followed by a lattice translation. There is a Berry phase and a plaquette spin flux due to spin procession as electrons hop between Ir atoms, akin to the intersite spin-orbit coupling in quantum spin Hall insulators. The associated staggered circulating J eff ¼ 1=2 spin current can be probed by advanced techniques of spin-current detection in spintronics. This electronic order can emerge spontaneously from the intersite Coulomb interactions between the spatially extended iridium 5d orbitals, turning the metallic state into an electron-doped quasi-2D Dirac semimetal with important implications on the possible superconducting state suggested by recent experiments. . The canting of the inplane magnetic moments tracks the θ ≃ 11°staggered IrO 6 octahedra rotation about the c axis [3][4][5][6] due to the strong spin-orbit coupling (SOC). The AFM insulating state arises from a novel interplay between SOC and electron correlation most easily understood near the atomic limit. Ir 4þ has a 5d 5 configuration. The 5 electrons occupy the lower threefold t 2g orbitals separated from the higher twofold e g orbitals by the cubic crystal field Δ c . The strong atomic SOC λ SOC splits the t 2g orbitals into a low-lying J eff ¼ 3=2 spin-orbit multiplet occupied by 4 electrons and a singly occupied J eff ¼ 1=2 doublet. Assuming λ SOC and Δ c are sufficiently large compared to the relevant bandwidths when Sr 2 IrO 4 crystalizes, a single J eff ¼ 1=2 band is half filled and can be driven by a moderate local Coulomb repulsion U to an AFM Mott insulating state [1,2,7]. The nature of the spin-orbit entangled insulating state has been studied using the localized picture based on the J eff ¼ 1=2 pseudospin anisotropic Heisenberg model [7][8][9][10][11], the three-orbital Hubbard model for the t 2g electrons with SOC [12][13][14][15], and the microscopic correlated density functional theory such as the LDA þ U and GGA þ U [1, [16][17][18]. Moreover, carrier doping the AFM insulating state was proposed to potentially realize a 5d t 2g -electron analog of the 3d e g -electron high-T c cuprate superconductors [8,12,13,19,20].In this work, we study the hidden order in both stoichiometric and electron-doped Sr...

show abstract

Electron and hole doping in the relativistic Mott insulator Sr2IrO4 : A first-principles study using band unfolding technique

Cited by 31 publications

References 48 publications

Infrared probe of pseudogap in electron-doped Sr2IrO4

Infrared probe of pseudogap in electron-doped Sr2IrO4

Evolution of the remnant Fermi-surface state in the lightly doped correlated spin-orbit insulator Sr2−xLaxIrO4

Correlation Effects and Hidden Spin-Orbit Entangled Electronic Order in Parent and Electron-Doped Iridates Sr2IrO4

Contact Info

Product

Resources

About