TY - JOUR
T1 - Novel Fe-Based Superconductor LaFe2As2 in Comparison with Traditional Pnictides
AU - Mazin, I. I.
AU - Shimizu, Makoto
AU - Takemori, Nayuta
AU - Jeschke, Harald O.
N1 - Funding Information:
I. I. M. acknowledges support by ONR through the NRL basic research program and by the Research Institute for Interdisciplinary Science, Okayama University visiting scientist program. We acknowledge helpful discussions with H. Shinaoka and J. Otsuki.
Publisher Copyright:
© 2019 American Physical Society. American Physical Society.
PY - 2019/12/31
Y1 - 2019/12/31
N2 - The recently discovered Fe-based superconductor (FeBS) LaFe2As2 seems to break away from an established pattern that doping an FeBS beyond 0.2e/Fe destroys superconductivity. LaFe2As2 has an apparent doping of 0.5e, yet superconducts at 12.1 K. Its Fermi surface bears no visual resemblance with the canonical FeBS fermiology. It also exhibits two phases, none magnetic and only one superconducting. We show that the difference between them nonetheless has a magnetic origin, the one featuring disordered moments, and the other locally nonmagnetic. We find that La there assumes an unusual valence of +2.6 to +2.7, so that the effective doping is reduced to 0.30-0.35e. A closer look reveals the same key elements: hole Fermi surfaces near Γ-Z and electron ones near the X-P lines, with the corresponding peak in susceptibility, and a strong tendency to stripe magnetism. The physics of LaFe2As2 is thus more similar to the FeBS paradigm than hitherto appreciated.
AB - The recently discovered Fe-based superconductor (FeBS) LaFe2As2 seems to break away from an established pattern that doping an FeBS beyond 0.2e/Fe destroys superconductivity. LaFe2As2 has an apparent doping of 0.5e, yet superconducts at 12.1 K. Its Fermi surface bears no visual resemblance with the canonical FeBS fermiology. It also exhibits two phases, none magnetic and only one superconducting. We show that the difference between them nonetheless has a magnetic origin, the one featuring disordered moments, and the other locally nonmagnetic. We find that La there assumes an unusual valence of +2.6 to +2.7, so that the effective doping is reduced to 0.30-0.35e. A closer look reveals the same key elements: hole Fermi surfaces near Γ-Z and electron ones near the X-P lines, with the corresponding peak in susceptibility, and a strong tendency to stripe magnetism. The physics of LaFe2As2 is thus more similar to the FeBS paradigm than hitherto appreciated.
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U2 - 10.1103/PhysRevLett.123.267001
DO - 10.1103/PhysRevLett.123.267001
M3 - Article
C2 - 31951452
AN - SCOPUS:85078009892
SN - 0031-9007
VL - 123
JO - Physical Review Letters
JF - Physical Review Letters
IS - 26
M1 - 267001
ER -