A nearly free electron metal and a Mott insulating state can be thought of as opposite ends of possibilities for the motion of electrons in a solid. In the magnetic oxide metal PdCrO2, these two coexist as alternating layers. Using angle resolved photoemission, we surprisingly find sharp band-like features in the one-electron removal spectral function of the correlated subsystem. We show that these arise because a hole created in the Mott layer moves to and propagates in the metallic layer while retaining memory of the Mott layer's magnetism. This picture is quantitatively supported by a strong coupling analysis capturing the physics of PdCrO2 in terms of a Kondo lattice Hamiltonian. Our findings open new routes to use the non-magnetic probe of photoemission to gain insights into the spin-susceptibility of correlated electron systems.
@article{arxiv.1809.08972,
title = {Probing spin correlations using angle resolved photoemission in a coupled metallic/Mott insulator system},
author = {V. Sunko and F. Mazzola and S. Kitamura and S. Khim and P. Kushwaha and O. J. Clark and M. Watson and I. Markovic and D. Biswas and L. Pourovskii and T. K. Kim and T. -L. Lee and P. K. Thakur and H. Rosner and A. Georges and R. Moessner and T. Oka and A. P. Mackenzie and P. D. C. King},
journal= {arXiv preprint arXiv:1809.08972},
year = {2020}
}