The dynamic behavior of electrons in magnetic fields is crucial for understanding physical processes, such as the quantum Hall effect, which are important in many areas of solid state physics, including electrical conductivity. Yet, there is much that remains unknown about exactly how electrons behave in a magnetic field.
In research published today in Nature Communications, researchers Franco Nori and Konstantin Bliokh from the RIKEN Center for Emergent Matter Science in Japan, in collaboration with an experimental team in Austria, have made the first direct observations of free-electron Landau states—a form of quantized states that electrons adopt when moving through a magnetic field—and found that the internal rotational dynamics of quantum electrons, or how they move through the field, is surprisingly different from the classical model, and in line with recent quantum-mechanical predictions made at RIKEN.
The experimental team used a transmission electron microscope to generate nanometer-sized electron vortex beams in which the electrons had a variety of quantum angular-momentum states, and then analyzed the beam propagation to reconstruct the rotational dynamics of the electrons in different Landau states.
According to classical physics, the electrons should rotate uniformly at what is called the cyclotron frequency, the frequency adopted by a charged particle moving through a magnetic field.
Remarkably, what the researchers discovered is that in fact, depending on the quantum number describing the angular momentum, the electrons rotated in three different ways with zero frequency, the cyclotron frequency, and the Larmor frequency, which is half the cyclotron frequency.
This shows that the rotational dynamics of the electrons are more complex and intriguing than was once believed.
According to Franco Nori, who leads the RIKEN team, "This is a very exciting finding, and it will contribute to a better understanding of the fundamental quantum features of electrons in magnetic fields, and help us to reach a better understanding of Landau states and various related physical phenomena."
Jens Wilkinson | Eurek Alert!
Absorbing acoustics with soundless spirals
10.02.2016 | American Institute of Physics
Hot Science of the Cold Universe
10.02.2016 | Max-Planck-Institut für Radioastronomie
Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically so far. Their optical ytterbium clock achieved a relative systematic measurement uncertainty of 3 E-18. The results have been published in the current issue of the scientific journal "Physical Review Letters".
Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock...
The University of Würzburg has two new space projects in the pipeline which are concerned with the observation of planets and autonomous fault correction aboard satellites. The German Federal Ministry of Economic Affairs and Energy funds the projects with around 1.6 million euros.
Detecting tornadoes that sweep across Mars. Discovering meteors that fall to Earth. Investigating strange lightning that flashes from Earth's atmosphere into...
Physicists from Saarland University and the ESPCI in Paris have shown how liquids on solid surfaces can be made to slide over the surface a bit like a bobsleigh on ice. The key is to apply a coating at the boundary between the liquid and the surface that induces the liquid to slip. This results in an increase in the average flow velocity of the liquid and its throughput. This was demonstrated by studying the behaviour of droplets on surfaces with different coatings as they evolved into the equilibrium state. The results could prove useful in optimizing industrial processes, such as the extrusion of plastics.
The study has been published in the respected academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).
Exceeding critical temperature limits in the Southern Ocean may cause the collapse of ice sheets and a sharp rise in sea levels
A future warming of the Southern Ocean caused by rising greenhouse gas concentrations in the atmosphere may severely disrupt the stability of the West...
Indications of light-induced lossless electricity transmission in fullerenes contribute to the search for superconducting materials for practical applications.
Superconductors have long been confined to niche applications, due to the fact that the highest temperature at which even the best of these materials becomes...
09.02.2016 | Event News
02.02.2016 | Event News
26.01.2016 | Event News
10.02.2016 | Life Sciences
10.02.2016 | Earth Sciences
10.02.2016 | Physics and Astronomy