Evidence of strong correlations and coherence-incoherence crossover in the iron pnictide superconductor KFe2As2

F. Hardy; A. E. Böhmer; D. Aoki; P. Burger; T. Wolf; P. Schweiss; R. Heid; P. Adelmann; Y. X. Yao; G. Kotliar; J. Schmalian; C. Meingast

doi:10.1103/PhysRevLett.111.027002

Evidence of strong correlations and coherence-incoherence crossover in the iron pnictide superconductor KFe₂As₂

F. Hardy, A. E. Böhmer, D. Aoki, P. Burger, T. Wolf, P. Schweiss, R. Heid, P. Adelmann, Y. X. Yao, G. Kotliar, J. Schmalian, C. Meingast

School of Arts and Sciences, Physics & Astronomy

Research output: Contribution to journal › Article › peer-review

115 Scopus citations

Abstract

Using resistivity, heat-capacity, thermal-expansion, and susceptibility measurements we study the normal-state behavior of KFe₂As ₂. Both the Sommerfeld coefficient (γ≈103 mJ mol ^-1 K^-2) and the Pauli susceptibility (χ≈4× 10^-4) are strongly enhanced, which confirm the existence of heavy quasiparticles inferred from previous de Haas-van Alphen and angle-resolved photoemission spectroscopy experiments. We discuss this large enhancement using a Gutzwiller slave-boson mean-field calculation, which shows the proximity of KFe₂As₂ to an orbital-selective Mott transition. The temperature dependence of the magnetic susceptibility and the thermal expansion provide strong experimental evidence for the existence of a coherence- incoherence crossover, similar to what is found in heavy fermion and ruthenate compounds, due to Hund's coupling between orbitals.

Original language	English (US)
Article number	027002
Journal	Physical review letters
Volume	111
Issue number	2
DOIs	https://doi.org/10.1103/PhysRevLett.111.027002
State	Published - Jul 9 2013

All Science Journal Classification (ASJC) codes

Physics and Astronomy(all)

Access to Document

10.1103/PhysRevLett.111.027002

Cite this

@article{1634cbca12ad44b4a58af487f15b8e77,

title = "Evidence of strong correlations and coherence-incoherence crossover in the iron pnictide superconductor KFe2As2",

abstract = "Using resistivity, heat-capacity, thermal-expansion, and susceptibility measurements we study the normal-state behavior of KFe2As 2. Both the Sommerfeld coefficient (γ≈103 mJ mol -1 K-2) and the Pauli susceptibility (χ≈4× 10-4) are strongly enhanced, which confirm the existence of heavy quasiparticles inferred from previous de Haas-van Alphen and angle-resolved photoemission spectroscopy experiments. We discuss this large enhancement using a Gutzwiller slave-boson mean-field calculation, which shows the proximity of KFe2As2 to an orbital-selective Mott transition. The temperature dependence of the magnetic susceptibility and the thermal expansion provide strong experimental evidence for the existence of a coherence- incoherence crossover, similar to what is found in heavy fermion and ruthenate compounds, due to Hund's coupling between orbitals.",

author = "F. Hardy and B{\"o}hmer, {A. E.} and D. Aoki and P. Burger and T. Wolf and P. Schweiss and R. Heid and P. Adelmann and Yao, {Y. X.} and G. Kotliar and J. Schmalian and C. Meingast",

year = "2013",

month = jul,

day = "9",

doi = "10.1103/PhysRevLett.111.027002",

language = "English (US)",

volume = "111",

journal = "Physical Review Letters",

issn = "0031-9007",

publisher = "American Physical Society",

number = "2",

}

TY - JOUR

T1 - Evidence of strong correlations and coherence-incoherence crossover in the iron pnictide superconductor KFe2As2

AU - Hardy, F.

AU - Böhmer, A. E.

AU - Aoki, D.

AU - Burger, P.

AU - Wolf, T.

AU - Schweiss, P.

AU - Heid, R.

AU - Adelmann, P.

AU - Yao, Y. X.

AU - Kotliar, G.

AU - Schmalian, J.

AU - Meingast, C.

PY - 2013/7/9

Y1 - 2013/7/9

N2 - Using resistivity, heat-capacity, thermal-expansion, and susceptibility measurements we study the normal-state behavior of KFe2As 2. Both the Sommerfeld coefficient (γ≈103 mJ mol -1 K-2) and the Pauli susceptibility (χ≈4× 10-4) are strongly enhanced, which confirm the existence of heavy quasiparticles inferred from previous de Haas-van Alphen and angle-resolved photoemission spectroscopy experiments. We discuss this large enhancement using a Gutzwiller slave-boson mean-field calculation, which shows the proximity of KFe2As2 to an orbital-selective Mott transition. The temperature dependence of the magnetic susceptibility and the thermal expansion provide strong experimental evidence for the existence of a coherence- incoherence crossover, similar to what is found in heavy fermion and ruthenate compounds, due to Hund's coupling between orbitals.

AB - Using resistivity, heat-capacity, thermal-expansion, and susceptibility measurements we study the normal-state behavior of KFe2As 2. Both the Sommerfeld coefficient (γ≈103 mJ mol -1 K-2) and the Pauli susceptibility (χ≈4× 10-4) are strongly enhanced, which confirm the existence of heavy quasiparticles inferred from previous de Haas-van Alphen and angle-resolved photoemission spectroscopy experiments. We discuss this large enhancement using a Gutzwiller slave-boson mean-field calculation, which shows the proximity of KFe2As2 to an orbital-selective Mott transition. The temperature dependence of the magnetic susceptibility and the thermal expansion provide strong experimental evidence for the existence of a coherence- incoherence crossover, similar to what is found in heavy fermion and ruthenate compounds, due to Hund's coupling between orbitals.

UR - http://www.scopus.com/inward/record.url?scp=84880119326&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84880119326&partnerID=8YFLogxK

U2 - 10.1103/PhysRevLett.111.027002

DO - 10.1103/PhysRevLett.111.027002

M3 - Article

AN - SCOPUS:84880119326

SN - 0031-9007

VL - 111

JO - Physical Review Letters

JF - Physical Review Letters

IS - 2

M1 - 027002

ER -

Evidence of strong correlations and coherence-incoherence crossover in the iron pnictide superconductor KFe₂As₂

Abstract

All Science Journal Classification (ASJC) codes

Access to Document

Other files and links

Fingerprint

Cite this