According to the principles of quantum mechanics, particles can exhibit a phenomenon called quantum superposition, which allows them to exist in multiple states simultaneously. However, it's important to clarify that this does not imply that the particles themselves are physically occupying the same position in space at the same time.
In quantum mechanics, the position of a particle is described by a probability distribution called a wavefunction. When a particle is in a superposition of states, its wavefunction represents a combination of different possibilities. For example, an electron can exist in a superposition of being in two different places, but it does not mean that it occupies both positions simultaneously. Instead, the wavefunction represents the probability of finding the electron in each of those positions when a measurement is made.
If two particles are in an entangled state, their individual wavefunctions can be combined into a joint wavefunction that describes the system as a whole. In such cases, the particles' states become correlated, and measurements made on one particle can instantaneously affect the state of the other, regardless of the distance between them. However, this does not imply that the particles occupy the same position simultaneously. Each particle's wavefunction describes its own position and properties independently.
In summary, while quantum mechanics allows particles to exist in superpositions of states, it does not permit two different particles to occupy the same position in space at the same time. The concept of superposition refers to the probabilistic nature of particles' positions, and the behavior of multiple particles is described by their individual wavefunctions.