Light on heavy electrons
Nature Physics
July 27, 2009
Photons have revealed the heavy electrons that are behind the transition to the so-called 'hidden order' phase in the superconductor URu2Si2, researchers report online this week in Nature Physics. Although the microscopic nature of the hidden-order phase remains unknown, the experiment will help guide future studies of this enigma.
For nearly 25 years, the low-temperature phase of URu2Si2 has been a mystery. Although many other uranium-based superconductors contain heavy electrons, there has not been any direct evidence for heavy electrons in URu2Si2. Santander-Syro and colleagues use spectroscopic techniques to show that they exist and that they take part in the hidden-order change of state.
At the point which this phase change occurs, the Fermi surface separating the filled and unfilled electron states that define the properties of a given solid undergoes instability. The team detected a band of heavy-electron states above the transition, which then migrates into the hidden-order state, where the electrons develop a gap in their excitation energy. None of the present theories on hidden order have predicted this kind of behaviour.
doi: 10.1038/nphys1361
Research highlights
-
Jul 6
Biotechnology: Mice cloned from freeze-dried somatic cellsNature Communications
-
Jul 4
Particle physics: A decade of Higgs boson researchNature
-
Jul 1
Space health: The path of most resistance could help limit bone loss during spaceflightScientific Reports
-
Jun 30
Evolution: Hawks learn on the fly to swoop up before perchingNature
-
Jun 28
Astronomy: Hydrogen- and helium-rich exoplanets may provide habitable conditions for billions of yearsNature Astronomy
-
Jun 24
Sport science: New wearable sensor to measure neck strain may detect potential concussionScientific Reports