Quantum entanglement is a phenomenon where two or more particles become correlated in such a way that the state of one particle cannot be described independently of the state of the other particles, regardless of the distance between them. The maximum number of particles that can be quantum entangled is not limited in principle, but practical limitations arise due to various factors.
The main limitation is related to the complexity of maintaining and controlling entanglement as the number of particles increases. As the number of entangled particles grows, the overall system becomes more sensitive to external disturbances and interactions with the environment, making it challenging to preserve and manipulate the entanglement.
Additionally, the resources required to create and maintain entanglement scale exponentially with the number of particles. This exponential growth makes it increasingly difficult to scale up experiments with a large number of entangled particles.
Currently, the largest number of entangled particles achieved in a controlled experimental setting is around 20 to 100 particles, depending on the specific system and technology used. However, it's important to note that this number may change in the future as new technologies and techniques for generating and manipulating entanglement continue to develop.