Macroscopic quantum phenomena refer to quantum effects that manifest in systems at a macroscopic scale, as opposed to being limited to the atomic or subatomic levels typical in quantum mechanics. These phenomena arise when a large number of particles exhibit collective quantum behavior, leading to observable effects that can be measured in everyday macroscopic systems. Some key examples include: 1. **Superconductivity**: This is a state in which certain materials exhibit zero electrical resistance and the expulsion of magnetic fields below a certain temperature.
