Superconductivity in pressurized trilayer La4Ni3O10−δ single crystals

The pursuit of discovering new high-temperature superconductors that diverge from the copper-based model1–3 has profound implications for explaining mechanisms behind superconductivity and may also enable new applications4–8. Here our investigation shows that the application of pressure effectively suppresses the spin–charge order in trilayer nickelate La4Ni3O10−δ single crystals, leading to the emergence of superconductivity with a maximum critical temperature (Tc) of around 30 K at 69.0 GPa. The d.c. susceptibility measurements confirm a substantial diamagnetic response below Tc, indicating the presence of bulk superconductivity with a volume fraction exceeding 80%. In the normal state, we observe a strange metal behaviour, characterized by a linear temperature-dependent resistance extending up to 300 K. Furthermore, the layer-dependent superconductivity observed hints at a unique interlayer coupling mechanism specific to nickelates, setting them apart from cuprates in this regard. Our findings provide crucial insights into the fundamental mechanisms underpinning superconductivity, while also introducing a new material platform to explore the intricate interplay between the spin–charge order, flat band structures, interlayer coupling, strange metal behaviour and high-temperature superconductivity.