"Quantum entanglement is the 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."
The concept of entanglement, the Bell inequality, and quantum teleportation.
Quantum Mechanics: Quantum mechanics is the branch of physics that describes the behavior of matter and energy at the quantum scale, which is very small.
Superposition: Superposition refers to the principle that a quantum particle can exist in multiple states simultaneously.
Wave-particle duality: Wave-particle duality refers to the idea that quantum particles can behave like waves and particles at the same time.
Quantum entanglement: Quantum entanglement refers to the phenomenon in which two or more quantum particles become connected and can influence each other's behavior, even when separated by large distances.
Bell's theorem: Bell's theorem is a fundamental result in quantum mechanics that shows that the predictions of quantum mechanics cannot be explained by any theory that relies on local hidden variables.
Quantum teleportation: Quantum teleportation is a process through which the quantum state of one particle can be transmitted to another particle, even if they are separated by a large distance.
Quantum cryptography: Quantum cryptography is a method of secure communication that uses quantum mechanical principles to exchange keys.
Quantum computation: Quantum computation is the use of quantum mechanical phenomena, such as superposition and entanglement, to perform computations that are impossible with classical computers.
Quantum field theory: Quantum field theory is a branch of physics that combines quantum mechanics and special relativity to describe the behavior of subatomic particles and their interactions.
Quantum information theory: Quantum information theory is a branch of information theory that deals with the processing, transmission, and storage of quantum information.
Quantum decoherence: Quantum decoherence is the process by which the quantum coherence of a system is lost due to its interaction with the environment.
Quantum measurement problem: The quantum measurement problem is the question of how to reconcile the deterministic laws of quantum mechanics with the apparent randomness of the measurement process.
Quantum gravity: Quantum gravity is the theoretical framework that attempts to unify quantum mechanics and general relativity, the two pillars of modern physics.
Spin Entanglement: This type of entanglement occurs when two spin-1/2 particles are created in a system where their total spin is measured to be zero.
Polarization Entanglement: This type of entanglement occurs within a photon. Two or more photons may be polarized in such a way that their polarization states are entangled.
Position Entanglement: This type of entanglement correlates the position of one particle with the position of another. The position of one particle is not certain unless the position of the entangled particle is also being observed.
Time Entanglement: This type of entanglement occurs when two particles are entangled in their time of arrival. The arrival time of one particle affects the arrival time of the entangled particle in a way that cannot be predicted using classical mechanics.
Energy Entanglement: This type of entanglement refers to when two particles' energies are entangled, creating uncertainty in the energy of each particle.
"Entanglement is a primary feature of quantum mechanics not present 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."
"Any measurement of a particle's properties results in an apparent and irreversible wave function collapse of that particle and changes the original quantum state."
"Such phenomena were the subject of a 1935 paper by Albert Einstein, Boris Podolsky, and Nathan Rosen, and several papers by Erwin Schrödinger shortly thereafter."
"Einstein and others considered such behavior impossible, as it violated the local realism view of causality (Einstein referring to it as 'spooky action at a distance') and argued that the accepted formulation of quantum mechanics must therefore be incomplete."
"The counterintuitive predictions of quantum mechanics were verified in tests where polarization or spin of entangled particles were measured at separate locations, statistically violating Bell's inequality."
"In earlier tests, it could not be ruled out that the result at one point could have been subtly transmitted to the remote point, affecting the outcome at the second location. However, so-called 'loophole-free' Bell tests have since been performed where the locations were sufficiently separated that communications at the speed of light would have taken longer—in one case, 10,000 times longer—than the interval between the measurements."
"According to some interpretations of quantum mechanics, the effect of one measurement occurs instantly."
"Other interpretations which do not recognize wavefunction collapse dispute that there is any 'effect' at all."
"Despite popular thought to the contrary, quantum entanglement cannot be used for faster-than-light communication."
"On 14 August 2023, researchers reported the first-ever image of quantum entanglement." Note: Some questions might require the synthesis of information from multiple parts of the paragraph.