Superconductor-insulator-normal metal

Tunneling electric current through the normal metal insulator superconductor junction is accompanied with heat flow out of normal metal when property voltage is biased. The phenomenon enables cooling of electrons and phonons (under special conditions) in the region below 1K. At lower bath temperatures, two parasitic heat sources decrease refrigerator performance ... 

The tunneling process across a SIN (superconductor-insulator-normal metal) junction is more complicated than across a NIN (normal metal-insulator-normal metal) junction described in sec. 3.2. An electron reacliing an insulator (1) from a normal metal (N) takes either one of four elementary processes, i.e., (1) reflection as an electron... 

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. 

In conclusion, we mention that the effects of disorder on the kinetics of quasiparticles confined in an insulator/normal-metal/superconductor (INS) hybrid structure due to Andreev reflections was first considered in Ref. [12] within a model where the disorder is provided by irregularities on the I/N boundary through the normal scattering of quasiparticles. 

A Josephson junction consists of two closely spaced superconductors separated by a weak connection (Figure 4.6.1). This connection may be provided by an insulator, a normal metal, a semiconductor, a weakened superconductor, or some other material that weakly couples the two superconductors. The two superconducting regions may be characterized by quantum mechanical wave functions and 2 respectively. Normally a much more complicated description would be necessary because... 

Josephson affects Electrical effects observed when two superconducting materials (at low temperature) are separated by a thin layer of insulating material (typically a layer of oxide less than 10 m thick). If normal metallic conductors are separated by such a battier it is possible for a small current to flow between the conductors by the turmel effect. If the materials are superconductors (see suPERCONDUcnvTTY), several unusual phenomena occur ... 

Once the specimen turns to a superconducting state, the obtained superconductor-insulator-normal metal (SIN) spectrum probes the quasiparticle excitation in the superconductor, which directly reflects the symmetry of the order parameter A(k). If A(k) has simple s-wave symmetry, as is realized in conventional low-temperature superconductors, one expects a finite gap of A with overshooting peaks just outside the gap in N(E), as illustrated in fig. 6. Even if A(k) possesses anisotropic s-wave symmetry, a finite gap, corresponding to the minimum gap, appears. In dx2-yi superconductors with A(k) = coslkx - cos 2, in contrast, N(E) is gapless with linear N(E) for E A. It is noted that the extended-s wave A(x) = cos 2kx + cos 2ky is also characterized to possess a gapless feature with two singularities bX E = A and A2. 

The temperature dependence of the poly(3-hexylthio-phene)/Pbo.. Bii.7Sri,6Ca 2.4CU3O10 contact resistance above displays an activated behavior, with the contact resistance increasing as the temperature is lowered from room temperature to 110 K (Fig. 37.14A). However. as Tc(onset) is approached, the contact resistance decreases dramatically. Unlike data acquired with normal metal/high-Tc structures, where the values of the contact resistance become vanishingly small below 7, the contact resistance for the polymer/superconductor structure possesses a small but finite value at low temperatures. The presence of a short segment of polymer that extends onto the insulating matrix and is not in di-... 

In a sense, a superconductor is an insulator that has been doped (contains random defects in the metal oxide lattice). Some of the defects observed via neutron diffraction experiments include metal site substitutions or vacancies, and oxygen vacancies or interstituals (atomic locations between normal atom positions). Neutron diffraction experiments have been an indispensable tool for probing the presence of vacancies, substitutions, or interstituals because of the approximately equal scattering power of all atoms. 

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