A simple method, based on the Meissner effect, is suggested for identifying a possible room-temperature
ambient-pressure superconductor with 100% certainty, which may be called the “Superconductor
Exclusion Principle”. In July 2023, LK-99 was claimed to be a room-temperature ambient-pressure
superconductor, and it produced huge interest around the world, because of its potential applications in
many industry sectors. However, it is difficult to produce pure samples for zero-resistance measurement.
We point out that a neodymium magnet can exhibit superconductivity because of the Meissner effect,
that is, diamagnetism, levitation, and quantum locking (levitation below a magnet), even for tiny
samples. Nevertheless, this approach has never been systematically pursued. We stress that accurate Tc
measurement is possible from quantum locking. The suggested Superconductor Exclusion Principle is,
“if any proposed material does not show diamagnetism, levitation, and quantum locking in one sample,
the material is not a superconductor.” Note that CES-2023, discovered by Cutting Edge Superconductors
on September 28, 2023, is a room temperature ambient pressure superconductor of Tc approximately
104° C = 377 K, according to this Superconductor Exclusion Principle.
