Electron Glass Phase with Resilient Zhang-Rice Singlets in LiCu3O3

Consiglio, A., Gatti, G., Martino, E., Moreschini, L., Johannsen, J. C., Prša, K., Freeman, Paul Gregory orcid iconORCID: 0000-0002-5376-8940, Sheptyakov, D., Rønnow, H. M. et al (2024) Electron Glass Phase with Resilient Zhang-Rice Singlets in LiCu3O3. Physical Review Letters, 132 (12). ISSN 0031-9007

[thumbnail of AAM]
PDF (AAM) - Accepted Version

Official URL: https://doi.org/10.1103/PhysRevLett.132.126502


LiCu3O3 is an antiferromagnetic mixed valence cuprate where trilayers of edge-sharing Cu(II)O (3d9) are sandwiched in between planes of Cu(I) (3d10) ions, with Li stochastically substituting Cu(II). Angle-resolved photoemission spectroscopy (ARPES) and density functional theory reveal two insulating electronic subsystems that are segregated in spite of sharing common oxygen atoms: a Cu dz2/O pz derived valence band (VB) dispersing on the Cu(I) plane, and a Cu 3dx2−y2/O 2px,y derived Zhang-Rice singlet (ZRS) band dispersing on the Cu(II)O planes. First-principle analysis shows the Li substitution to stabilize the insulating ground state, but only if antiferromagnetic correlations are present. Li further induces substitutional disorder and a 2D electron glass behavior in charge transport, reflected in a large 530 meV Coulomb gap and a linear suppression of VB spectral weight at EF that is observed by ARPES. Surprisingly, the disorder leaves the Cu(II)-derived ZRS largely unaffected. This indicates a local segregation of Li and Cu atoms onto the two separate corner-sharing Cu(II)O2 sub-lattices of the edge-sharing Cu(II)O planes, and highlights the ubiquitous resilience of the entangled two hole ZRS entity against impurity scattering.

Repository Staff Only: item control page