Hidden Mott insulator in metallic PdCrO${}_2$

Abstract

There has been a long-standing debate on the coexistence between itinerant electrons and localized spins in the PdCrO${}_2$ delafossite. By means of the charge self-consistent combination of density functional theory and dynamical mean-field theory, it is corroborated that despite overall remarkable metallic response, the CrO${}_2$ layers are indeed Mott insulating as suggested by previous experimental work. The resulting $\mathbf{k}$-resolved spectral function in the paramagnetic phase is in excellent agreement with available photoemission data. Subtle coupling between the itinerant and Mott-localized degrees of freedom is revealed. Different doping scenarios are simulated in order to manipulate the electronic states within the inert layers. In particular, oxygen vacancies prove effective in turning the hidden Mott insulator into a strongly correlated itinerant subsystem. The present results may open a new venue in research on quantum materials beyond canonical classification schemes.

7 pages, 6 figures

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Cited by in corpus (10)

• From basic properties to the Mott design of correlated delafossites
• The planar triangular $S=3/2$ magnet AgCrSe${}_2$: magnetic frustration, short range correlations, and field tuned anisotropic cycloidal magnetic order
• Electrons in helical magnetic field: a new class of topological metals
• Dynamical Mean-Field Theory of Strongly Correlated Electron Systems
• Unconventional magnetism and electronic state in frustrated layered system PdCrO${}_2$
• Avoided metallicity in a hole-doped Mott insulator on a triangular lattice
• Probing hidden Mott gap and incommensurate charge modulation on the polar surfaces of PdCrO${}_2$
• Theoretical design of highly correlated electron states in delafossite heterostructures
• Probing spin correlations using angle resolved photoemission in a coupled metallic/Mott insulator system
• Heisenberg spins on an anisotropic triangular lattice: PdCrO2 under uniaxial stress