Immediately with the discovery of high-Tc superconductivity in the Ruddlesden-Popper Nickelates, the question of the responsible superconducting pairing mechanism arose. One clue might be found in the pressure-temperature phase diagram: at ambient pressure, metallic multi-band behaviour is observed, together with multiple density wave (DW) phases. Yet, with increasing pressure, the DW phases are suppressed and superconductivity emerges. This phase diagram is reminiscent of other strongly correlated superconductors, especially the iron-pnictides and iron-chalcogenides, and thus suggests that (quantum) critical fluctuations of the DW phase might be a key ingredient for superconductivity.

In this contribution, we will show that this is not the case in the case of La4Ni3O10 single crystals. By carefully tuning the hydrostatic and/or uniaxial pressure environment, we can separate the DW ordered phase and superconductivity and disentangle them completely. We conclude that the DW phase and superconductivity are either antagonists, or exist independently of each other. Moreover, we solve the puzzle of seemingly non-reproducible transport properties between different research groups, which we will assign to differences in the pressure environment and the contact layout.