The effect of compression on the magnetic ground state of Sr2IrO4 is studied with x-ray resonant techniques in the diamond anvil cell. The weak interlayer exchange coupling between square-planar 2D IrO2 layers is readily modified upon compression, with a crossover between magnetic structures around 7 GPa mimicking the effect of an applied magnetic field at ambient pressure. Higher pressures drive an order-disorder magnetic phase transition with no magnetic order detected above 17-20 GPa. The persistence of strong exchange interactions between Jeff=1/2 magnetic moments within the insulating IrO2 layers up to at least 35 GPa points to a highly frustrated magnetic state in compressed Sr2IrO4 opening the door for realization of novel quantum paramagnetic phases driven by extended 5d orbitals with entangled spin and orbital degrees of freedom.
@article{arxiv.1911.09786,
title = {Possible quantum paramagnetism in compressed Sr$_2$IrO$_4$},
author = {D. Haskel and G. Fabbris and J. H. Kim and L. S. I. Veiga and J. R. L. Mardegan and C. A. Escanhoela and S. Chikara and V. Struzhkin and T. Senthil and B. J. Kim and G. Cao and J. W. Kim},
journal= {arXiv preprint arXiv:1911.09786},
year = {2020}
}
Comments
4 pages, 3 figures, see ancillary file for Supplemental Material