quantum theory tagged posts

Experiment verifies a Connection between Quantum Theory and Information Theory

A connection between quantum theory and information theory proved
With the help of a new experiment, researchers at Linköping University, among others, have succeeded in confirming a 10-year-old theoretical study that connects one of the most fundamental aspects of quantum mechanics—the complementarity principle—with information theory. Credit: Magnus Johansson

Researchers from Linköping University together with colleagues from Poland and Chile have confirmed a theory that proposes a connection between the complementarity principle and entropic uncertainty. Their study is published in the journal Science Advances.

“Our results have no clear or direct application right now. It’s basic research that lays the foundation for future technologies in quantum information and quantum computers...

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Curved Spacetime in a Quantum Simulator

[Translate to English:] Montage aus Astronomie-Foto von Gravitationslinseneffekt und Teilchen

The theory of relativity works well when you want to explain cosmic-scale phenomena—such as the gravitational waves created when black holes collide. Quantum theory works well when describing particle-scale phenomena—such as the behavior of individual electrons in an atom. But combining the two in a completely satisfactory way has yet to be achieved. The search for a “quantum theory of gravity” is considered one of the significant unsolved tasks of science.

This is partly because the mathematics in this field is highly complicated...

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Entanglement is an Inevitable Feature of Reality

Jonathan G. Richens, John H. Selby, and Sabri W. Al-Safi. "Entanglement is Necessary for Emergent Classicality in All Physical Theories." Physical Review Letters. DOI: 10.1103/PhysRevLett.119.080503

Jonathan G. Richens, John H. Selby, and Sabri W. Al-Safi. “Entanglement is Necessary for Emergent Classicality in All Physical Theories.” Physical Review Letters. DOI: 10.1103/PhysRevLett.119.080503

Is entanglement really necessary for describing the physical world, or is it possible to have some post-quantum theory without entanglement? In a new study, physicists have mathematically proved that any theory that has a classical limit-meaning that it can describe our observations of the classical world by recovering classical theory under certain conditions-must contain entanglement...

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Magnetic Switch Turns Strange Quantum Property Berry Phase On and Off

These images show the orbital paths of electrons trapped within a circular region within graphene. In the classical orbit (top image), an electron that travels in a complete circuit has the same physical state as when it started on the path. However, when an applied magnetic field reaches a critical value, (bottom image), an electron completing a circuit has a different physical state its original one. The change is called a Berry phase, and the magnetic field acts as a switch to turn the Berry phase on. The result is that the electron is raised to a higher energy level. Credit: Christopher Gutiérrez, Daniel Walkup/NIST

These images show the orbital paths of electrons trapped within a circular region within graphene. In the classical orbit (top image), an electron that travels in a complete circuit has the same physical state as when it started on the path. However, when an applied magnetic field reaches a critical value, (bottom image), an electron completing a circuit has a different physical state its original one. The change is called a Berry phase, and the magnetic field acts as a switch to turn the Berry phase on. The result is that the electron is raised to a higher energy level.
Credit: Christopher Gutiérrez, Daniel Walkup/NIST

The discovery promises new insight into quantum theory and may lead to new quantum electronic devices...

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