La nuclear quadrupole resonance studies of pressurized LaNiO
arXiv:2609.06453
Abstract
Density-wave (DW) orders are considered as competing orders to unconventional superconductivity and are commonly seen in a variety of superconductors including but not limited to the recently discovered Ruddlesden-Popper-phase nickelates. By utilizing La nuclear quadrupole resonance, we systematically investigate into the nature of DW orders and their evolution under pressure in LaNiO. Spin and charge DW orders are found to be intertwined in this material, which is in stark contrast to those in LaNiO. Short-range DW orders are observed near 150 K, well above the development of long-range DW orders at around 139 K. Upon applying a hydrostatic pressure of 2.3 GPa, the transition temperatures of the short-range and long-range orders decrease at rates of 1 K/GPa and 10 K/GPa, respectively. Our results thus affirm that both spin density wave and charge density wave as competing orders with the superconducting state in LaNiO, and provide new insights into the interplay between DW orders and unconventional superconductivity.
8+4 pages, 4+3 figures