In the context of entangled particles, the process of separating them is often referred to as "spatial separation." When entangled particles are spatially separated, their properties remain correlated, even if they are far apart. However, the specific limitations on the separation distance depend on various factors, including the nature of the entangled particles and the experimental setup.
In theory, there is no fundamental restriction on the distance over which entangled particles can be separated. However, in practical experiments, there are challenges that arise as the separation distance increases. These challenges include factors such as environmental noise, decoherence, and the limitations of current technology.
When entangled particles are spatially separated, it's essential to consider the interactions between each particle and its surrounding environment. These interactions can potentially disrupt the entanglement or introduce unwanted correlations that may affect the desired communication. Interactions with classical fields or other particles in the environment can lead to decoherence, which is the loss of quantum coherence and the degradation of entanglement.
To mitigate the effects of these interactions, researchers often strive to isolate the entangled particles from their surroundings as much as possible. Techniques such as shielding, cooling, and vacuum environments are employed to minimize external influences and preserve the entanglement.
Regarding your question about "tangential" versus "radical" separation, it is not a commonly used terminology in the context of entanglement. The key factor is the preservation of entanglement, which depends on minimizing the interactions with the environment rather than the specific direction or angle of separation. Researchers aim to maximize the separation distance while maintaining the entangled state, regardless of the direction.
It's worth noting that the practicality and feasibility of long-distance entanglement-based communication are active areas of research and technological development. Scientists are exploring various methods, such as quantum repeaters and satellite-based communication, to overcome the challenges associated with spatial separation and realize long-distance entanglement-based communication systems.