We studied resistance oscillations in two types of superconducting mesoscopic Nb rings. In a simple superconducting ring device, a resistance oscillation with a period of the quantized magnetic flux h/2e was clearly observed. On the other hand, in a micro-bridge ring device where two-narrow parts are embedded in parallel and work as superconductor-normal metal-superconductor junctions, higher harmonic resistance oscillations were obtained when the measurement current was well-tuned. We argue that such higher harmonic resistance oscillations can be detected even in the micro-bridge Nb superconducting ring device where the device size is much larger than the coherence length of Nb.

Magnetoresistance measurements have been performed in CeTe3 thin film devices in a temperature range from 2.1 to 20 K up to 8 T. A clear Shubnikov-de-Haas oscillation was observed in the whole temperature range. The temperature dependence of the oscillation amplitude was found to deviate from the Lifshitz–Kosevich formula below the magnetic transition temperature at TN1 ≈ 3 K. This indicates a significant interplay between the magnetic ordering and the conduction electrons, which could lead to a modification of the effective cyclotron mass. By analyzing the temperature dependence of the oscillation amplitude, we have estimated the effective mass, quantum lifetime and quantum mobility of the material both in the paramagnetic and antiferromagnetic states.

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We studied charge density wave (CDW) transitions in NbSe 3 devices with thicknesses t from 20 to 170 nm, fabricated by the mechanical exfoliation technique. NbSe 3 exhibits two CDW transitions: one is the linear nesting (CDW1) below » T 140 1 K and the other is the diagonal nesting (CDW2) below » T 60 2 K. For both the transitions, clear resistivity changes were observed down to t = 20 nm, indicating that the CDW states are robust even for the thin NbSe 3 devices. The result also suggests that surface acoustic waves could be useful to modulate the CDW in the NbSe 3 devices.