Self-Doping Induced Orbital-Selective Mott Transition in Hg2Ru2O7

Abstract

Pyrochlore oxides are fascinating systems where strong, multi-orbital correlations in concert with geometrical frustration give rise to unanticipated physical properties. The detailed mechanism of the insulator-metal transitions (IMT) underpinning these phenomena is, however, ill-understood in general. Motivated thereby, we study the IMT in the pyrochlore $\mathrm{H}{\mathrm{g}}_2\mathrm{R}{\mathrm{u}}_2{\mathrm{O}}_7$ using LDA+DMFT. In contrast to the well-known examples of Mott transitions in TMO, we show that, in the negative charge-transfer situation characteristic of \hg, self-doping plays a crucial role in the emergence of an orbital-selective IMT. We argue that this mechanism has broader relevance to other correlated pyrochlore oxides.

5 pages, 3 figures

References in corpus (4)

• NiO: Correlated Bandstructure of a Charge-Transfer Insulator
• Valence bond crystal in a pyrochlore antiferromagnet with orbital degeneracy
• Metal-insulator Transition in a Pyrochlore-type Ruthenium oxide, Hg2Ru2O7
• Electronic structure and effects of dynamical electron correlation in ferromagnetic bcc-Fe, fcc-Ni and antiferromagnetic NiO