> [!infobox] <s class="aside-in"><em>mentioned in 1 topic, 1 source</em></s> #### <s class="topic-title">[[quantum entanglement]]</s> > [!wikipedia] [quantum entanglement](https://en.wikipedia.org/wiki/Quantum%20entanglement) > > Quantum entanglement is a physical phenomenon that occurs when a group of particles are generated, interact, or share spatial proximity in a way such that the quantum state of each particle of the group cannot be described independently of the state of the others, including when the particles are separated by a large distance. The topic of quantum entanglement is at the heart of the disparity between classical and [[quantum physics]]: entanglement is a primary feature of [[quantum mechanics]] lacking in [[classical mechanics]]. > > Measurements of physical properties such as [[position]], [[momentum]], [[spin]], and [[polarization]] performed on entangled particles can, in some cases, be found to be perfectly correlated. For example, if a pair of entangled particles is generated such that their total spin is known to be zero, and one particle is found to have clockwise spin on a first axis, then the spin of the other particle, measured on the same axis, is found to be counterclockwise. However, this behavior gives rise to seemingly paradoxical effects: any measurement of a particle's properties results in an irreversible wave function collapse of that particle and changes the original quantum state. With entangled particles, such measurements affect the entangled system as a whole. > > According to some interpretations of quantum mechanics, the effect of one measurement occurs instantly. Other interpretations which don't recognize wavefunction collapse dispute that there is any "effect" at all. However, all interpretations agree that entanglement produces correlation between the measurements and that the mutual information between the entangled particles can be exploited, but that any transmission of information at faster-than-light speeds is impossible. > > Quantum entanglement has been demonstrated experimentally with [[photons]], [[neutrinos]], [[electrons]], molecules as large as buckyballs, and even small diamonds. The utilization of entanglement in communication, computation and quantum radar is a very active area of research and development. > ##### ^dataviews > [!dataview]+ Related unlinked notes > > No results to show for list query. > [!dataview]- Other unlinked mentions > > - [[video - A brief history of quantom mechanics]]