Selective Mott Physics as a Key to Iron Superconductors

Medici, Luca de’; Giovannetti, Gianluca; Capone, Massimo

doi:10.1103/physrevlett.112.177001

Cited by 377 publications

(505 citation statements)

References 43 publications

Supporting

Mentioning

464

Contrasting

Unclassified

Order By: Relevance

“…Since there is no particle-hole symmetry in the Fe 3+ channel, it is interesting to inquire as to the effects of electron doping (n ≡ 5 ± δ) in this half-filled electronic reservoir. It is worth noticing here that electron-electron interactions are expected to reach their max- imum at half-filling and to decrease away from this configuration [38]. This expected electronic behavior is consistent with our results in Fig.…”

Section: Introductionsupporting

confidence: 81%

Site-selective electronic structure of pure and doped Ca2O3Fe3S2

et al. 2018

View full text Add to dashboard Cite

Using density functional dynamical mean-field theory we investigate the site-selective electronic structure of Ca 2 O 3 Fe 3 S 2 . We confirm that the parent compound with two distinct iron sites is a multiorbital Mott insulator similar to La 2 O 3 Fe 2 S 2 . Upon electron/hole doping, carrier localization is found to persist in the two active iron channels because the chemical potential lies in a gap structure with anisotropic and almost vanishing states near the Fermi energy. This emergent behavior stems from large electronic reconstruction caused by dynamical spectral weight transfer involving states with distinct d-shell occupancies and orbital character at low energies. We detail the implications of our microscopic analysis and discuss the underlying physics which will emerge in future experiments on Ca 2 O 3 Fe 3 S 2 .

show abstract

Section: Introductionsupporting

confidence: 81%

Site-selective electronic structure of pure and doped Ca2O3Fe3S2

et al. 2018

View full text Add to dashboard Cite

show abstract

“…The superconducting phase in NaFe 1−x Cu x As near x ≈ 0.02 can be continuously tuned to the antiferromagnetically ordered insulating phase with significant electronic correlations near x ≈0.5 through a region of short-range cation and magnetic order 19 , pointing to the possibility of the generic phase diagram of iron pnictides to be anchored around a Mott-insulating state 10,20 . The observation of a spin resonance mode in superconducting NaFe 1−x Cu x As demonstrates that the superconducting state is similar to other iron pnictide superconductors, and therefore electronic correlations should be an integral part of the physics of iron pnictide superconductors.…”

Section: Discussionmentioning

confidence: 99%

“…Superconductivity in iron pnictides, on the other hand, is derived from parent compounds that are bad metals [3][4][5] . Despite the metallic ground state of the parent compounds, strong electronic correlations are suggested to be present in iron pnictides [6][7][8] , especially in heavily hole-doped systems [9][10][11] . In addition to replacing A in AFe 2 As 2 (A = Ca, Sr, Ba) with alkaline metals (K, Na, Rb, Cs) 4,5 , hole-doping in iron pnictides can be achieved through Mn or Cr doping on Fe site although no superconductivity is induced in these cases 12,13 .…”

Section: Introductionmentioning

confidence: 99%

Phase diagram and neutron spin resonance of superconducting NaFe1−xCuxAs

et al. 2017

View full text Add to dashboard Cite

We use transport and neutron scattering to study the electronic phase diagram and spin excitations of NaFe1−xCuxAs single crystals. Similar to Co-and Ni-doped NaFeAs, a bulk superconducting phase appears near x ≈ 2% with the suppression of stripe-type magnetic order in NaFeAs. Upon further increasing Cu concentration the system becomes insulating, culminating in an antiferromagnetically ordered insulating phase near x ≈ 50%. Using transport measurements, we demonstrate that the resistivity in NaFe1−xCuxAs exhibits non-Fermi-liquid behavior near x ≈ 1.8%. Our inelastic neutron scattering experiments reveal a single neutron spin resonance mode exhibiting weak dispersion along c-axis in NaFe0.98Cu0.02As. The resonance is high in energy relative to the superconducting transition temperature Tc but weak in intensity, likely resulting from impurity effects. These results are similar to other iron pnictides superconductors despite the superconducting phase in NaFe1−xCuxAs is continuously connected to an antiferromagnetically ordered insulating phase near x ≈ 50% with significant electronic correlations. Therefore, electron correlations is an important ingredient of superconductivity in NaFe1−xCuxAs and other iron pnictides.

show abstract

“…This suppresses the d i,xy ↔ d j,xy hopping, and makes t ij xy,xy significantly smaller than the other tunneling amplitudes. Thus the d xy electrons are much more localized then the rest, and in some cases may even undergo an orbitally-selective Mott transition 33,34 .…”

mentioning

confidence: 99%

Nematicity driven by hybridization in iron-based superconductors

Stanev

Littlewood

2013

Phys. Rev. B

View full text Add to dashboard Cite

In this paper we study an effective model for the normal state of iron-based superconductors. It has separate, but interacting itinerant and localized degrees of freedom, originating from the dxz and dyz, and from dxy iron orbitals respectively. At low temperatures, below a mean-field phase transition, these different states condense together in an excitonic order parameter. We show that at even lower temperature, after another phase transition, this ordered state can spontaneously break the C4 lattice symmetry and become nematic. We propose this mechanism as an explanation of the tendency towards nematicity observed in several iron-based compounds.Introduction. The discovery of high-temperature superconductivity in iron-based materials 1-3 is one of the most exciting recent developments in physics. It is almost certain that the origin of superconductivity is unconventional (i.e. driven by electron-electron interactions), and is very likely that the order parameter is unconventional as well 4,5 . The normal state properties of these materials, in contrast, at first seemed rather unremarkablea bad metal behavior at high temperatures, which can be followed by structural transition and antiferromagnetic phase at low temperatures. This simple picture was considerably complicated by the growing evidence of nematic fluctuations 6-8 or even long-range order 9 present in some compounds at temperatures well above the antiferromagnetic and structural transitions. Furthermore, this nematicity seems to be of purely electronic (rather than structural) origin 10 . Understanding this state and its connection to the other phases is an important milestone in the study of these materials.

show abstract

Selective Mott Physics as a Key to Iron Superconductors

Cited by 377 publications

References 43 publications

Site-selective electronic structure of pure and doped Ca2O3Fe3S2

Site-selective electronic structure of pure and doped Ca2O3Fe3S2

Phase diagram and neutron spin resonance of superconducting NaFe1−xCuxAs

Nematicity driven by hybridization in iron-based superconductors

Contact Info

Product

Resources

About