Quantum entanglement is a fundamental phenomenon in quantum mechanics that has been extensively studied and verified through experiments. While there is no universally agreed-upon interpretation of the exact underlying mechanism of quantum entanglement, it is described and predicted by the mathematical formalism of quantum mechanics, which has been highly successful in explaining and predicting a wide range of experimental results.
In quantum mechanics, entanglement arises when 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(s). This correlation persists even when the particles are physically separated from each other. This means that the properties of entangled particles are intertwined, and measuring one particle can instantaneously affect the state of the other, regardless of the distance between them. This non-local correlation is what makes quantum entanglement so puzzling and fascinating.
The mathematical formalism of quantum mechanics provides a precise description of entangled states and their behavior. It uses the concept of superposition, which allows particles to exist in multiple states simultaneously, and the principle of quantum measurement, which describes how the act of measurement "collapses" the superposition into a definite state. When two particles are entangled, their individual states are described by a combined state, known as a quantum state or a wave function, that cannot be decomposed into separate states for each particle.
While the mathematical framework of quantum mechanics accurately predicts and explains the correlations observed in entangled systems, the interpretation of these predictions is still a subject of debate among physicists. There are several interpretations of quantum mechanics, such as the Copenhagen interpretation, the many-worlds interpretation, and the pilot-wave theory (also known as the de Broglie-Bohm theory), among others. These interpretations offer different perspectives on the nature of quantum entanglement, but they all agree on the mathematical formalism and the empirical predictions of quantum mechanics.
It's important to note that while the existence and behavior of quantum entanglement have been extensively tested and confirmed through numerous experiments, the deeper underlying mechanisms that give rise to entanglement are still actively researched and an area of ongoing scientific investigation.