Electronic instability, layer selectivity, and Fermi arcs in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mtext>La</mml:mtext><mml:mn>3</mml:mn></mml:msub><mml:msub><mml:mtext>Ni</mml:mtext><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mtext>O</mml:mtext><mml:mn>7</mml:mn></mml:msub></mml:mrow></mml:math>
Frank Lechermann, Steffen Bötzel, Ilya Eremin
Abstract
Using advanced dynamical mean-field theory on a realistic level we study the normal-state correlated electronic structure of the high-pressure superconductor ${\mathrm{La}}_{3}{\mathrm{Ni}}_{2}{\mathrm{O}}_{7}$ and compare the features of the conventional bilayer (2222) Ruddelsden-Popper crystal structure with those of a newly identified monolayer-trilayer (1313) alternation. Both structural cases display Ni-${d}_{{z}^{2}}$ flat-band character at low energy, which drives an electronic instability with a wave vector ${\mathbf{q}}_{\mathrm{I}}=(0.25,0.25,{q}_{z})$ at ambient pressure, in line with recent experimental findings. The 1313 electronic structure exhibits significant layer selectivity, rendering especially the monolayer part to be Mott critical. At high pressure, this layer selectivity weakens and the 1313 fermiology displays arcs reminiscent to those of high-${T}_{c}$ cuprates. In contrast to dominant intersite self-energy effects in the latter systems, here the Fermi arcs are the result of the multiorbital and multilayer interplay within a correlated flat-band scenario.