Phase Diagram of Nickelate Superconductors Calculated by Dynamical Vertex Approximation

• DOI: 10.3389/fphy.2021.810394
• Publication Date: 2022-01-21T07:47:48Z
• Authors: Karsten Held; Liang Si; Paul Worm; Oleg Janson; Ryotaro Arita; Zhicheng Zhong; Jan M. Tomczak; Motoharu Kitatani
• Keywords: Strongly Correlated Electrons (cond-mat.str-el); electronic structure calculations; Physics; QC1-999; Condensed Matter - Superconductivity; solid state theory; dynamical mean field theory; FOS: Physical sciences; 01 natural sciences; Superconductivity (cond-mat.supr-con); Condensed Matter - Strongly Correlated Electrons; high-temperature superconductivity; electronic correlation; 0103 physical sciences

We review the electronic structure of nickelate superconductors with and without effects correlations. As a minimal model, we identify one-band Hubbard model for Ni 3 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m1"><mml:msub><mml:mrow><mml:mi>d</mml:mi></mml:mrow><mml:mrow><mml:msup><mml:mrow><mml:mi>x</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:mo>−</mml:mo><mml:msup><mml:mrow><mml:mi>y</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:msub></mml:math> orbital plus pocket around A -momentum. The latter, however, merely acts as decoupled electron reservoir. This reservoir makes careful translation from nominal Sr-doping to doping mandatory. Our dynamical mean-field theory calculations, in part already supported by experiment, indicate that Γ pocket, Nd 4 f orbitals, oxygen 2 p , other d orbitals are not relevant superconducting regime. physics is completely different if topotactic hydrogen present or reduction incomplete. Then, two-band hosted id="m2"><mml:msub><mml:mrow><mml:mi>d</mml:mi></mml:mrow><mml:mrow><mml:msup><mml:mrow><mml:mi>x</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:mo>−</mml:mo><mml:msup><mml:mrow><mml:mi>y</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:msub></mml:math> id="m3"><mml:msub><mml:mrow><mml:mi>d</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn><mml:msup><mml:mrow><mml:mi>z</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:mo>−</mml:mo><mml:msup><mml:mrow><mml:mi>r</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:msub></mml:math> emerges. Based on our modeling, calculated T c vs. x phase diagram prior experiment using vertex approximation. For such notoriously difficult determine quantity agreement astonishingly good. prediction enhanced pressure compressive strain has been confirmed experimentally well. supports an appropriate model.