The unconventional electronic ground state of Sr3IrRuO7 is explored via resonant x-ray scattering techniques and angle-resolved photoemission measurements. As the Ru content approaches x=0.5 in Sr3(Ir1−xRux)2O7, intermediate to the Jeff=1/2 Mott state in Sr3Ir2O7 and the quantum critical metal in Sr3Ru2O7, a thermodynamically distinct metallic state emerges. The electronic structure of this intermediate phase lacks coherent quasiparticles, and charge transport exhibits a linear temperature dependence over a wide range of temperatures. Spin dynamics associated with the long-range antiferromagnetism of this phase show nearly local, overdamped magnetic excitations and an anomalously large energy scale of 200 meV---an energy far in excess of exchange energies present within either the Sr3Ir2O7 or Sr3Ru2O7 solid-solution endpoints. Overdamped quasiparticle dynamics driven by strong spin-charge coupling are proposed to explain the incoherent spectral features of the strange metal state in Sr3IrRuO7.
@article{arxiv.1903.06115,
title = {Overdamped antiferromagnetic strange metal state in Sr$_3$IrRuO$_7$},
author = {Julian L. Schmehr and Thomas R. Mion and Zach Porter and Michael Aling and Huibo Cao and Mary H. Upton and Zahirul Islam and Rui-Hua He and Rajdeep Sensarma and Nandini Trivedi and Stephen D. Wilson},
journal= {arXiv preprint arXiv:1903.06115},
year = {2019}
}