Quantum magnetoresistive (hc/2e)/m periodic oscillations in a superconducting ring
V. I. Kuznetsov, O. V. Trofimov
备注:
8 pages, 8 figures; the author's translation of the original Russian text: V.I. Kuznetsov, O.V. Trofimov, Pis'ma v Zhurnal Eksperimental'noi i Teoreticheskoi Fiziki 110, 47 (2019)
发表信息:
JETP Lett. 110, 54 (2019) (original Russian text: Pis'ma v Zhurnal Eksperimental'noi i Teoreticheskoi Fiziki 110, 47 (2019))
It was experimentally found that quantum magnetoresistive hc/2e periodic oscillations of the Little-Parks type in a superconducting mesoscopic ring with decreasing temperature and increasing applied dc current are modified to the sum of harmonic (hc/2e)/m periodic oscillations. Multiple Andreev reflection can be a possible cause of this effect.
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 supercond…
Fractional-flux Little-Parks resistance oscillations in disordered superconducting Au$_{0.7}$In$_{0.3}$ cylinders
测量了无序超导Au $_{0.7}$ In $_{0.3}$圆柱薄膜的电阻随外加磁场的变化。在超导转变区的高温部分,电阻以封闭磁通量为单位以$h/2e$为周期振荡。然而,在较低的温度下,电阻峰值分裂。我们认为,这种分裂是由于出现了一个振荡周期为$h/4e$,一半的通量量子成对电子。讨论了无序超导圆柱自由能新极小值的背景下,可能的物理起源的$h/4e$电阻振荡。
Superconducting transition temperature of Pb nanofilms: Impact of the thickness-dependent oscillations of the phonon mediated electron-electron coupling
Half-quantum vortices in spin-triplet superconductors are predicted to host Majorana zero modes and may provide a viable platform for topological quantum computation. Recent works also suggested that, in thin mesoscopic rings, the superconducting pairing symmetry can be probed via Little-Parks-like magnetoresistance oscillations of periodicity $Φ_0 = h / 2e$ that persist below the critical temperature. Here we use the London limit of Ginzburg-Landau theory to study these magnetoresistance oscillations resulting from thermal vortex tunneling in spin-triplet superconducting rings. For a range of…
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