The concept of 'quantum critical point', the zero temperature point of a line of 2nd order phase transitions, is rather modern: It is nowadays strongly investigated mainly in connection with unconventional superconductivity. Recent experimental and theoretical works have shown that some metals show competing ferro- and antiferromagnetic order at very low temperature. This allows for the possibility of multiple critical points and thus, at T=0, for quantum tricritical points.[more]
Today’s world, rapidly changing because of “big data”, is encapsulated in trillions of tiny magnetic objects – magnetic bits – each of which stores one bit of data in magnetic disk drives. A group of scientists from the Max Planck Institutes in Halle and Dresden have discovered a new kind of magnetic nano-object in a novel material that could serve as a magnetic bit with cloaking properties to make a magnetic disk drive with no moving parts – a Racetrack Memory – a reality in the near future.
The National Natural Science Foundation of China honors Dr. Enke Liu, a Humboldt research fellow of the Alexander von Humboldt Foundation, with the 2017 National Science Fund for Excellent Young Scholars for his great contribution to magnetic phase transitions. This scholarship serves as a substantial bolster to the young talents in China.
The group “Micro Structured Quantum Matters” at MPI-CPfS develops microscopic electric conducting paths made of quantum materials to understand their physical properties and to test possible applications in new types of electronics. In cooperation with US scientists, they succeeded in showing a rare state in microchips in which electrons move together. That state is called “electronic nematicity”. It occurs in high magnetic fields in a layered metal made of cerium, rhodium and indium, called CeRhIn5. In an article published in the journal “Nature”, the scientists point to a new approach of understanding the link between electronic nematicity and superconductivity. Electrons move together in the superconductivity as well and links between the two phenomena were assumed for a long time.
Researchers find path to discovering new topological materials, holding promise for technological applications.
An international team of researchers has found a way to determine whether a crystal is a topological insulator — and to predict crystal structures and chemical compositions in which new ones can arise. The results, published July 20 in the journal Nature, show that topological insulators are much more common in nature than currently believed.
Scientists from the Max Planck Institute for chemical Physics of solids in Dresden discovered a system where a charge order can be continuously tuned to T = 0 by chemical substitution. Surprisingly, they observed a strong enhancement of superconductivity just at the quantum critical point where the charge order disappears. This opens a new window for studying the relation between superconductivity and critical fluctuations at quantum critical points.