Graphite is a model system for the study of electrons in the so-called magnetic quantum limit. This quantum limit is attained when the magnetic field is strong enough to confine the charge carriers to their lowest Landau levels. It is expected that the model of the free electron gas fails beyond this limit since here electron interactions may play a significant role in determining the electronic ground state. Indeed, our thermodynamic studies in high magnetic field revealed that even electron-lattice interaction has to be taken into account in addition to electron-electron interaction.
The simple cubic structure of CeB6 does not change while intricate multipolar phenomena are developed upon a non-magnetic La substitution. However, phase diagrams of Ce1-xLaxB6 have been elusive for the last decades. Recently, detailed phase transitions in Ce1-xLaxB6 have been revealed by scientists of MPI-CPfS, TU-Dresden, and I. M. Frantsevich Institute. In addition, a simple feature which is likely to be observed in a multipolar heavy-fermion system has been found.
The premartensite phase of shape memory and magnetic shape memory alloys is believed to be a precursor state of the martensite phase with preserved austenite phase symmetry. The thermodynamic stability of the premartensite phase and its relation to the martensitic phase is still an unresolved issue, even though it is critical to the understanding of the functional properties of magnetic shape memory alloys.[more]
Steffen Wirth erhält die Fellowship für „seine grundlegenden Beiträge zu unserem Verständnis von stark korrelierten Elektronensystemen, insbesondere bei reduzierten Längenskalen, einschließlich des Kondo-Effekts und magnetischer Wechselwirkungen", wie es in der Ernennungsurkunde heißt.
The surfaces of materials can host unique electronic properties, where the electrons behave very differently from the interior. In particular, the intrinsically broken symmetries of the surface compared with the bulk of the sample allows for a separation of energy states according to their spin. This effect could be utilised in novel electronic devices which operate with both the charge and spin of electrons- but it is first necessary to understand how to maximise the magnitude of the effect.
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.