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McNally, Daniel; Zellman, Shelby; Post, Kirk; He, Hong; Hao, Kuan-Rong; Kotliar, Gabriel; Basov, D. N.; Homes, C. C.; Aronson, M. C.

doi:10.1103/physrevb.92.115142

Cited by 32 publications

(28 citation statements)

References 39 publications

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“…One may speculate that the origin of this difference lies precisely in the half-filled shell: Hund's coupling induces a high-spin configuration, which is maximally efficient in suppressing charge and spin fluctuations, restoring an unrenormalized band picture. This is consistent with findings within DFT + DMFT calculations that indicate that Hund's coupling (J H ) is responsible for the insulating nature of BaMn 2 As 2 [33], and that the (metallic) band structure calculated without Hund's coupling is significantly more renormalized than in the calculation that includes a finite J H .…”

Section: Resultssupporting

confidence: 89%

Angle-resolved photoemission observation of Mn-pnictide hybridization and negligible band structure renormalization in BaMn2As2 and BaMn2Sb2
Zhang¹,
Richard²,
Roekeghem³
et al. 2016
Phys. Rev. B
23
4
27
0
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We performed an angle-resolved photoemission spectroscopy study of BaMn2As2 and BaMn2Sb2, which are isostructural to the parent compound BaFe2As2 of the 122 family of ferropnictide superconductors. We show the existence of a strongly kz-dependent band gap with a minimum at the Brillouin zone center, in agreement with their semiconducting properties. Despite the half-filling of the electronic 3d shell, we show that the band structure in these materials is almost not renormalized from the Kohn-Sham bands of density functional theory. Our photon energy dependent study provides evidence for Mn-pnictide hybridization, which may play a role in tuning the electronic correlations in these compounds.

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Section: Resultssupporting

confidence: 89%

Angle-resolved photoemission observation of Mn-pnictide hybridization and negligible band structure renormalization in BaMn2As2 and BaMn2Sb2
Zhang¹,
Richard²,
Roekeghem³
et al. 2016
Phys. Rev. B
23
4
27
0
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“…It is interesting to compare INS results described here to similar square lattice Mn-based compounds, such as LaMnAsO [30], LaMnPO [24], BaMn 2 Bi 2 [31] and AMnBi 2 (A=Sr,Ca) [32]. Both LaMnAsO and LaMnPO were studied using INS on polycrystalline samples.…”

Section: Resultsmentioning

confidence: 99%

Robust antiferromagnetic spin waves across the metal-insulator transition in hole-doped BaMn2As2

et al. 2017

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BaMn2As2 is an antiferromagnetic insulator where a metal-insulator transition occurs with hole doping via the substitution of Ba with K. The metal-insulator transition causes only a small suppression of the Néel temperature (TN) and the ordered moment, suggesting that doped holes interact weakly with the Mn spin system. Powder inelastic neutron scattering measurements were performed on three different powder samples of Ba1−xKxMn2As2 with x =0, 0.125 and 0.25 to study the effect of hole doping and metallization on the spin dynamics of these compounds. We compare the neutron intensities to a linear spin wave theory approximation to the J1 − J2 − Jc Heisenberg model. Hole doping is found to introduce only minor modifications to the exchange energies and spin gap. The changes observed in the exchange constants are consistent with the small drop of TN with doping. INTRODUCTIONThe parent compounds of unconventional superconductors are typically antiferromagnetic (AFM), although they may be initially metals (as in the iron pnictides [1]) or Mott insulators (as in the copper oxide superconductors [2]). In either case, chemical substitution is often employed to destabilize the AFM ordered state and give rise to a superconducting ground state over some composition range. For the iron arsenides, they are already metallic and adding charge carriers serves to modify the Fermi surface and destabilize nesting-driven spin-density wave AFM order, resulting in superconductivity. In BaFe 2 As 2 , electrons or holes can be added via chemical substitutions such as Ba(Fe 1−x M x ) 2 As 2 with M = Co or Ni [3][4][5][6][7][8][9] and Ba 1−x K x Fe 2 As 2 [10], respectively.On the other hand, the effect of chemical substitutions in the copper oxides, such as La 2 CuO 4 , are twofold. Since they are insulators, chemical substitutions (such as La 2−x Sr x CuO 4 ) must both metallize the system and disrupt long-range AFM order in order to make the conditions favorable for superconductivity. In other words, both a metal-insulator transition and suppression of AFM order are necessary for superconductivity to appear in the cuprates.In attempting to find some commonality between the arsenides and cuprates, we search for other compounds that bridge these two systems. One possible system is BaMn 2 As 2 which shares the same crystal structure as BaFe 2 As 2 . Similar to cuprates, BaMn 2 As 2 is a quasitwo-dimensional AFM insulator possessing a square lattice of magnetic moments that order into a G-type AFM (checkerboard) pattern [11]. Also similar to the cuprates, a metal-insulator transition can be induced in BaMn 2 As 2 by replacing small amounts (a few percent) of Ba with K which effectively adds hole carriers [12,13]. Unlike the cuprates, the moments on Mn are large (S ≈ 2 to 5/2). In conjunction with large magnetic interactions (with a Néel transition temperature of T N = 625 K) [11,14,15], both neutron diffraction [16] and 75 As nuclear magnetic resonance [17] find that long-range AFM ordering is robust with hole doping, even at K concentra...

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“…In fact, there has been a revival of FL concepts in correlated systems beyond the cuprates [69,70]. For example, FL behavior has been found in the iron-pnictides [71,72], and for the Mn-pnictides the evolution from Hund's insulator to a FL was traced in an optical spectroscopy study [73]. Even the perfectly compensated semimetal WTe 2 , which features electron/hole pockets with a Fermi energy of 20-40 meV, exhibits a T 2 scattering rate up to high temperatures [74].…”

Section: Appendix a Fl Behavior In Correlated Systemsmentioning

confidence: 99%

Evidence for a universal Fermi-liquid scattering rate throughout the phase diagram of the copper-oxide superconductors

et al. 2019

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The phase diagram of the cuprate superconductors continues to pose formidable scientific challenges. While these materials are typically viewed as doped Mott insulators, it is well known that they are Fermi liquids at high hole-dopant concentrations. It was recently demonstrated that at moderate doping, in the pseudogap (PG) region of the phase diagram, the charge carriers are also best described as a Fermi liquid. Nevertheless, the relationship between the two Fermi-liquid (FL) regions and the nature of the strange-metal (SM) state at intermediate doping have remained unsolved. Here we show for the case of the model cuprate superconductor HgBa 2 CuO 4+δ that the normal-state transport scattering rate determined from the cotangent of the Hall angle remains quadratic in temperature across the PG temperature, upon entering the SM state, and that it is doping-independent below optimal doping. Analysis of prior transport results for other cuprates reveals that this behavior is universal throughout the entire phase diagram and points to a pervasive FL transport scattering rate. These observations can be reconciled with a variety of other experimental results for the cuprates upon considering the possibility that the PG phenomenon is associated with the gradual, non-uniform localization of one hole per planar CuO 2 unit.

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From Hund's insulator to Fermi liquid: Optical spectroscopy study of K doping inBaMn2As2

Cited by 32 publications

References 39 publications

Angle-resolved photoemission observation of Mn-pnictide hybridization and negligible band structure renormalization in BaMn2As2 and BaMn2Sb2
Zhang¹,
Richard²,
Roekeghem³
et al. 2016
Phys. Rev. B
23
4
27
0
View full text Add to dashboard Cite

Angle-resolved photoemission observation of Mn-pnictide hybridization and negligible band structure renormalization in BaMn2As2 and BaMn2Sb2
Zhang¹,
Richard²,
Roekeghem³
et al. 2016
Phys. Rev. B
23
4
27
0
View full text Add to dashboard Cite

Robust antiferromagnetic spin waves across the metal-insulator transition in hole-doped BaMn2As2

Evidence for a universal Fermi-liquid scattering rate throughout the phase diagram of the copper-oxide superconductors

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From Hund's insulator to Fermi liquid: Optical spectroscopy study of K doping inBaMn2As2

Cited by 32 publications

References 39 publications

Angle-resolved photoemission observation of Mn-pnictide hybridization and negligible band structure renormalization in BaMn2As2 and BaMn2Sb2Zhang1, Richard2, Roekeghem3 et al. 2016Phys. Rev. B234270View full textAdd to dashboardCite

Angle-resolved photoemission observation of Mn-pnictide hybridization and negligible band structure renormalization in BaMn2As2 and BaMn2Sb2Zhang1, Richard2, Roekeghem3 et al. 2016Phys. Rev. B234270View full textAdd to dashboardCite

Robust antiferromagnetic spin waves across the metal-insulator transition in hole-doped BaMn2As2

Evidence for a universal Fermi-liquid scattering rate throughout the phase diagram of the copper-oxide superconductors

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Product

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Angle-resolved photoemission observation of Mn-pnictide hybridization and negligible band structure renormalization in BaMn2As2 and BaMn2Sb2
Zhang¹,
Richard²,
Roekeghem³
et al. 2016
Phys. Rev. B
23
4
27
0
View full text Add to dashboard Cite

Angle-resolved photoemission observation of Mn-pnictide hybridization and negligible band structure renormalization in BaMn2As2 and BaMn2Sb2
Zhang¹,
Richard²,
Roekeghem³
et al. 2016
Phys. Rev. B
23
4
27
0
View full text Add to dashboard Cite