Normal state magnetoresistance

Investigations of the normal state magnetoresistance (MR) as well as the Hall effect and the thermal conductivity in the normal and superconducting mixed states give an important information about the electronic structure and the properties of vortex lattice of the investigated materials. 

Figure 41 shows that in the normal state HoNi2B2C has a considerably large magnetoresistance MR of negative sign. (The positive sign of MR in fig. 41a is due to the alternative normalization of this quantity which has been introduced so that data... 

From here follow main goals in the SIT problem to find theoretical models which would lead to the negative magnetoresistance to trace how the specific SIT properties appear in the field-induced superconductor-normal metal transition while the normal metal is shifted toward the insulating state to find out whether the low dimensions of the films is crucial or the SIT can happen in 3D materials to find the explanation for the pair localization alternative to the boson-vortex duality. It seems that the first two goals are achieved. 

Fig. 4. Normalized magnetoresistance (left axis) at several temperatures below /iT. The relative height of the resistive jump from the ordered to the disordered state is shown on the right axis. Solid dots refer to the magnetoresistance measurements, while open dots refer to temperature sweeps at fixed magnetic fields. The dotted line is a guide to the eye.

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