A novel canonical transformation provides insights into many-particle physics

February 16, 2016
Schematic illustration of the canonical transformation. Credit: (c) by IST Austria, 2016

The concepts of rotation and angular momentum play a crucial role in many areas of physics, ranging from nuclear spectroscopy to molecular collisions and precision measurements. In a paper appearing in the leading physics journal Physical Review X on February 12, 2016, Mikhail Lemeshko, Professor at the Institute of Science and Technology Austria (IST Austria), and Richard Schmidt, Postdoc at Harvard University, introduce a technique to understand and calculate angular momentum in settings where many particles interact with each other, so-called many-particle systems.

In the last 70 years, the quantum theory of angular momentum has been successfully used to describe the properties of nuclei, atoms and molecules. However, in most situations occurring in nature particles interact with each other, which makes it challenging to understand and calculate the angular momentum properties even for small systems. This applies in particular to realistic experiments where nuclei, atoms and molecules are almost never isolated. Instead, they are disturbed by their surrounding environment, be it a gas, a solution or lattice vibrations in a crystal. In such a situation, the angular momentum can be redistributed between infinitely many . Therefore, such settings are intractable using currently available mathematical approaches.

In their paper, Lemeshko and Schmidt introduce a new mathematical technique to calculate and understand the transfer of between a rotating impurity and a quantum many-particle system—so-called "angulon problem." The technique is based on a novel canonical transformation that removes the complex algebra involved in the problem and thereby drastically simplifies the understanding of angulon . Potentially, this technique can be applied to a broad range of problems in atomic, condensed matter, and chemical physics.

Explore further: Leiden physicists entangle four rotating photons

More information: Richard Schmidt et al. Deformation of a Quantum Many-Particle System by a Rotating Impurity, Physical Review X (2016). DOI: 10.1103/PhysRevX.6.011012

Related Stories

Leiden physicists entangle four rotating photons

February 3, 2016

For the first time, scientists have entangled four photons in their orbital angular momentum. Leiden physicists sent a laser through a crystal, thereby creating four photons with coupled 'rotation'. So far this has only been ...

Breaking nature's superfluid symmetry

September 6, 2013

Superfluids are an exotic state of matter in which particles flow without experiencing viscosity. Hiroki Ikegami and colleagues from the RIKEN Low Temperature Physics Laboratory in Wako have now observed another remarkable ...

Recommended for you

Electron highway inside crystal

December 8, 2016

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their ...

Researchers improve qubit lifetime for quantum computers

December 8, 2016

An international team of scientists has succeeded in making further improvements to the lifetime of superconducting quantum circuits. An important prerequisite for the realization of high-performance quantum computers is ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

forumid001
not rated yet Feb 18, 2016
nice work to follow up.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.