RYDBERG MOLECULE Meaning and
Definition
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A Rydberg molecule is a type of molecule formed through the interaction of two atoms, typically an alkali metal atom and a polarizable atom, under specific conditions. It is named after the Swedish physicist Johannes Rydberg, who first proposed the concept in the early 20th century.
In a Rydberg molecule, one of the atoms is in its highly excited state known as a Rydberg state, where the valence electron is in a high orbital with a large principal quantum number. Due to this highly excited state, the electron is located far from the atomic nucleus, resulting in a significant dipole moment. The other atom, which is usually an alkali metal, possesses a weakly bound electron.
The interaction between these two atoms occurs through the electric dipole-dipole interaction, with the highly excited Rydberg electron causing an attractive force between the atoms. This attraction leads to the formation of a weakly bound Rydberg molecule.
Rydberg molecules are characterized by their large internuclear distances, typically much larger than that of regular molecules, resulting in long-range interactions. Due to their weakly bound nature, they exhibit distinctive spectroscopic properties, such as the presence of vibrational and rotational states. In addition, Rydberg molecules can also form dimers, where two Rydberg molecules interact with each other.
The study of Rydberg molecules is of great interest in the field of atomic and molecular physics due to their unique properties and potential applications in areas such as ultracold chemistry, quantum information processing, and precision measurements.
Etymology of RYDBERG MOLECULE
The term "Rydberg molecule" is named after the Swedish physicist Johannes Rydberg (1854-1919). Johannes Rydberg is known for his significant contributions to the field of atomic physics, particularly for his formulation of the Rydberg formula, which describes the spectral lines of hydrogen atoms.
The term "Rydberg molecule" was introduced to describe a special type of molecule composed of an excited Rydberg atom and a ground-state atom or molecule. These exotic molecules formed by the binding of a Rydberg electron to a neutral atom or molecule were first observed and studied experimentally in the 1980s. Since these molecules involve Rydberg atoms, they were named "Rydberg molecules" in recognition of the contributions made by Johannes Rydberg to the understanding of excited atomic states.
