A research team led by Prof. Liu Xiaodi from the Hefei Institute of Physical Science of the Chinese Academy of Sciences, together with researchers from Jilin University and Sun Yat-sen University, has achieved simultaneous detection of zero electrical resistance and the Meissner effect in lanthanum nickelate (La₃Ni₂O_7−δ) single crystals under high pressure.

The researchers combined diamond nitrogen-vacancy (NV) center quantum sensing with electronic transport measurements to provide unambiguous evidence of high-temperature superconductivity in this nickelate system. The results are published in Physical Review Letters.

Superconductivity in La₃Ni₂O_7−δ was first reported in 2023 through transport measurements, which revealed zero resistance around 80 K. However, confirming superconductivity requires detecting diamagnetism, or the expulsion of magnetic fields—the Meissner effect—which had remained elusive due to technical challenges associated with high-pressure environments and small superconducting volume fractions.