Doping of a Mott insulator gives rise to a wide variety of exotic emergent states, from high-temperature superconductivity to charge, spin, and orbital orders. The physics underpinning their evolution is, however, poorly understood. A major challenge is the chemical complexity associated with traditional routes to doping. Here, we study the Mott insulating CrO2 layer of the delafossite PdCrO2, where an intrinsic polar catastrophe provides a clean route to doping of the surface. From scanning tunnelling microscopy and angle-resolved photoemission, we find that the surface stays insulating accompanied by a short-range ordered state. From density functional theory, we demonstrate how the formation of charge disproportionation results in an insulating ground state of the surface that is disparate from the hidden Mott insulator in the bulk. We demonstrate that voltage pulses induce local modifications to this state which relax over tens of minutes, pointing to a glassy nature of the charge order.
@article{arxiv.2311.17139,
title = {Avoided metallicity in a hole-doped Mott insulator on a triangular lattice},
author = {Chi Ming Yim and Gesa-R. Siemann and Srdjan Stavrić and Seunghyun Khim and Izidor Benedičič and Philip A. E. Murgatroyd and Tommaso Antonelli and Matthew D. Watson and Andrew P. Mackenzie and Silvia Picozzi and Phil D. C. King and Peter Wahl},
journal= {arXiv preprint arXiv:2311.17139},
year = {2024}
}
Comments
published paper and supplementary, 28 pages in total, 4 figures in the main text and 15 in the supplementary