The importance of shear on the collective charge transport in CDWs revealed by an XFEL source.

Charge transport in materials has an impact on a wide range of devices based on semiconductor, battery, or superconductor technology. Charge transport in sliding charge density waves (CDW) differs from all others in that the atomic lattice is directly involved in the transport process. To obtain an overall picture of the structural changes associated to the collective transport, the large coherent x-ray beam generated by an x-ray free-electron laser (XFEL) source was used.

Magnetic Phase Diagram of van der Waals Antiferromagnet TbTe.

Terbium tritelluride, TbTe, orders antiferromagnetically in three steps at = 6.7 K, = 5.7 K, and = 5.

Critical field of 2H-NbSe2 down to 50mK.

Critical field of 2H-NbSe2 is determined for the field perpendicular to the conducting planes down to 50 mK, by magnetoresistance measurements. It is the first time that such a measurement is extended below 1 K. Variations are almost linear down to 1 K, with a little upward curvature, and the slope of H c 2⊥ (T) decreases below 1 K.

Scanning-tunneling microscope imaging of single-electron solitons in a material with incommensurate charge-density waves.

We report on scanning-tunneling microscopy experiments in a charge-density wave (CDW) system allowing visually capturing and studying in detail the individual solitons corresponding to the self-trapping of just one electron. This "Amplitude Soliton" is marked by vanishing of the CDW amplitude and by the π shift of its phase. It might be the realization of the spinon--the long-sought particle (along with the holon) in the study of science of strongly correlated electronic systems.

Surface charge density wave phase transition in NbSe3.

The two charge-density wave (CDW) transitions in NbSe3 were investigated by scanning tunneling microscopy (STM) on an in situ cleaved (b, c) plane. The temperature dependence of first-order CDW satellite spots, obtained from the Fourier transform of the STM images, was measured between 5 and 140 K to extract the surface critical temperatures (T{s}). The low-T CDW transition occurs at T{2s}=70-75  K, more than 15 K above the bulk T{2b}=59  K while at exactly the same wave number.