quantum entanglement tagged posts

Paul Klimov, a graduate student in the University of Chicago’s Institute for Molecular Engineering, adjusts the intensity of a laser beam during an experiment. Because the laser light lies within the infrared spectrum, it is invisible to the human eye. Credit: University of Chicago

Entanglement says that 2 particles can be so inextricably connected that the state of one particle can instantly influence the state of the other, no matter how far apart they are. It will be useful for quantum computers, quantum communication networks, and high-precision quantum sensors.
Entanglement is also one of nature’s most elusive phenomena.

Producing entanglement between particles requires that they start out in a highly ordered state, which is disfavored by thermodynamics, the process that governs the i...

The shape and polarization of a conventional laser beam from a laser pointer mimics quantum entanglement when the laser beam has a polarization dependent shape. This can be used to encode twice as many bits of information as when the laser beam is “separable.” Credit: Giovanni Milione

In a classic eureka moment, a team of physicists is showing how beams from ordinary laser pointers mimic quantum entanglement with the potential of doubling the data speed of laser communication. Described by Albert Einstein as “spooky action at a distance,” when two quantum things are entangled, if one is ‘touched’ the other will ‘feel it,’ even if separated by a great distance.

“At the heart of quantum entanglement is ‘nonseparability’ — two entangled things are described by an unfactorizable equation,” sai...

Artistic Impression of the Entanglement of electrons

>> Refutes Einstein’s ‘God does not play dice’ with quantum ‘dice’ ie it gives the strongest refutation to date of his principle of ‘local realism,’ which says that the universe obeys laws, not chance, and that there is no communication faster than light. As described in Hanson’s group web the Delft experiment first “entangled” 2 electrons trapped inside 2 different diamond crystals, and then measured the electrons’ orientations. In quantum theory entanglement is powerful and mysterious: mathematically the 2 electrons are described by a single “wave-function” that only specifies whether they agree or disagree, not which direction either spin points. In a mathematical sense, they lose their identities...

The ‘just right’ structure that emerges when you drive a system containing light and matter (like the universe), neither too fast nor too slow across a quantum phase transition. It illustrates the findings of the study titled “Enhanced dynamic light-matter entanglement from driving neither too fast nor too slow,” published in the journal Physical Review. Credit: Oscar Acevedo, Universidad de los Andes, and Neil Johnson, University of Miami. The study is a collaboration between the Universidad de los Andes in Colombia and the University of Miami.

By studying a system that couples matter and light together, like the universe, researchers have found crossing a quantum phase transition at intermediate speeds generates the richest, most complex structure...