Magnetic field and hopping effects on the current-voltage characteristics in aGaAs/AlxGa1−xAsdouble-barrier heterostructure

2003 ◽  
Vol 68 (4) ◽  
Author(s):  
H. Paredes Gutiérrez ◽  
N. Porras-Montenegro ◽  
A. Latgé
2002 ◽  
Vol 12 (9) ◽  
pp. 119-122
Author(s):  
A. A. Sinchenko ◽  
P. Monceau

We have measured the differential current-voltage characteristics of normal metal-NbSe3 direct point contacts (without insulating barrier) formed along different crystallographic orientations under applied magnetic field with different orientations. At low temperature two energy gaps, $\Delta_{p1}$ and $\Delta_{p2}$, corresponding to the high and the low-temperature CDW were observed simultaneously as a singulanty of the excess resistance which is attributed to an analog of Andreev reflection, in which the incident electron reflects on the Peierls energy gap barriers with its charge unchanged. An applied magnetic field up to 8.5 T does not lead to a change in the density of states and in the Peierls energy gaps, suggesting that the large magnetoresistance observed in NbSe3 might not result from the change in the CDW order parameter with magnetic field but rather from the increase of scattering of non-condensed to CDW carriers.


2018 ◽  
Vol 185 ◽  
pp. 08005
Author(s):  
Alexander Sergeev ◽  
Igor Golev ◽  
Victoria Gvozdevskaya ◽  
Anastasia Barkalova

The nonlinear response of the superconductor of the Bi-Sr-Ca-Cu-O system in the temperature range of the superconducting transition under the action of a harmonic alternating magnetic field is experimentally studied. For multiphase superconductors having in their volume regions with distinct critical temperatures, the effect of odd harmonics in the response signal is observed. The contribution of crystallites and the system of weak bonds between the crystallites in the nonlinear response is singled out. It was found that the nonlinear properties of the investigated samples in the resistive state are determined mainly by the nonlinear current-voltage characteristics of the system of weak bonds between the crystallites.


2019 ◽  
Vol 970 ◽  
pp. 75-81
Author(s):  
Alexey Zavgorodniy ◽  
Aitbek Aimukhanov ◽  
Assylbek Zeinidenov ◽  
Galina Vavilova

The role of spin states in the process of charge carrier transport in copper phthalocyanine (CuPc) nanowires has been established. According to the data obtained, CuPc nanowires are in the η-phase. The current-voltage characteristics (IVC) of a photosensitive cell based on CuPc nanowires in a magnetic field are investigated. As a result of experiments, it was found that applying an external magnetic field, the spins of two positively charged polarons are oriented in one direction. The channel of formation of the bipolaron is blocked. As a result, a decrease in the short-circuit current of the photosensitive cell is observed by more than 61%.


1988 ◽  
Vol 02 (08) ◽  
pp. 1011-1015
Author(s):  
YONG ZHAO ◽  
QIRUI ZHANG ◽  
WEIYAN GUAN ◽  
JIANSHENG XIA ◽  
ZHENHUI HE ◽  
...  

The dependence of the resistance on the magnetic field and the current-voltage characteristics of the single phase Ba 2 YCu 3 O 7−δ have been measured. The nonmonotonic behavior and a hysteresis of R(H) and the current-voltage characteristics suggest that the granular superconductivity exist in this material, and it plays an important role in transport properties.


Sign in / Sign up

Export Citation Format

Share Document