Hall sensor system was used to measure the local critical current of YBCO tape with high spatial resolution under in-situ tensile stress. The hot spot generation and minimum quench energy of YBCO tape, which depended on the local critical current, was calculated through the thermoelectric coupling model. With the increase in tensile stress, the cracks which have different dimensions and critical current degradation arose more frequently and lowered the thermal stability of the YBCO tape.

One-dimensional (1D) aligned GeSi quantum dots (QDs) along 1D trenches have been prepared on the Si(0 0 1) substrates. The resistance values along the transverse and the longitudinal direction are significantly different at low temperatures. Two conductive layers are suggested to explain the difference. One is the boron doped layer which is at 10 nm underneath the QDs layer, the other is the QDs layer which is effective only for the longitudinal transport. Fitting the resistance as a function of temperature indicates that the conduction mechanism in both layers is two-dimensional Mott variable-range hopping. The magnetoresistance (MR) for the longitudinal transport at low temperatures shows a positive MR at low magnetic fields and a large negative MR at high fields. This behaviour is tentatively explained provided that the two conductive layers have different MR mechanisms.