Role of electron tunneling in spin filtering at ferromagnet/semiconductor interfaces

2003 ◽  
Vol 68 (7) ◽  
Author(s):  
S. E. Andresen ◽  
S. J. Steinmuller ◽  
A. Ionescu ◽  
G. Wastlbauer ◽  
C. M. Guertler ◽  
...  
2002 ◽  
Vol 66 (7) ◽  
Author(s):  
M. Syed ◽  
G. L. Yang ◽  
J. K. Furdyna ◽  
M. Dobrowolska ◽  
S. Lee ◽  
...  

1986 ◽  
Vol 77 ◽  
Author(s):  
A. F. J. Levi ◽  
R. T. Tung ◽  
J. L. Batstone ◽  
J. M. Gibson ◽  
M. Anzlowar ◽  
...  

ABSTRACTAbrupt, epitaxial silicide/silicon heterostructures may be grown so that, for the first time, the physics of electron transport across near perfect, single crystal, metal/semiconductor interfaces may be probed experimentally. Transport measurements through type-A and -B oriented NiSi2 layers on Si(111) substrates have revealed Schottky barrier heights differing by 140 meV. In this paper we present results of experiments designed to explore the possible role of bulk and interface defects in determining the potential barrier at these near ideal epitaxial metal-semiconductor contacts. We have found little evidence for the presence of defects and the Schottky barrier is insensitive to details of the microscopic interfacial perfection. By contrast we find that both the electrical quality and magnitude of the barrier occurring at the NiSi2 /Si(100) heterojunction are dependent upon details of the microscopic interfacial perfection.


2018 ◽  
Vol 924 ◽  
pp. 339-344 ◽  
Author(s):  
Fabrizio Roccaforte ◽  
Marilena Vivona ◽  
Giuseppe Greco ◽  
Raffaella Lo Nigro ◽  
Filippo Giannazzo ◽  
...  

The physics and technology of metal/semiconductor interfaces are key-points in the development of silicon carbide (SiC) based devices. Although in the last decade, the metal to 4H-SiC contacts, either Ohmic or Schottky type, have been extensively investigated with important achievements, these remain even now an intriguing topic since metal contacts are fundamental bricks of all electronic devices. Hence, their comprehension is at the base of the improvement of the performances of simple devices and complex systems. In this context, this paper aims to highlight some relevant aspects related to metal/semiconductor contacts to SiC, both on n-type and p-type, with an emphasis on the role of the barrier and on the carrier transport mechanisms at the interfaces.


2014 ◽  
Vol 104 (26) ◽  
pp. 263101 ◽  
Author(s):  
H. Kiyama ◽  
T. Fujita ◽  
S. Teraoka ◽  
A. Oiwa ◽  
S. Tarucha

1998 ◽  
Vol 37 (Part 1, No. 4B) ◽  
pp. 2281-2290 ◽  
Author(s):  
Konstantinos P. Giapis ◽  
Gyeong S. Hwang
Keyword(s):  

1989 ◽  
Vol 03 (03) ◽  
pp. 427-439 ◽  
Author(s):  
N. M. BOGOLIUBOV ◽  
V. E. KOREPIN

The critical exponents describing the decrease of correlation functions on long distances for the one-dimensional Hubbard model is obtained. The behaviour of correlators shows that Cooper pairs of electrons are formed. The electron tunneling between the chains leads to the existence of the anomalous mean values and to the superconductive current. The anisotropy of the quasi-one-dimensional system leads to the rise of critical temperature T c .


2020 ◽  
Author(s):  
Ashima Bajaj ◽  
Prabhleen Kaur ◽  
Aakanksha Sud ◽  
Marco Berritta ◽  
Md. Ehesan Ali

The molecular topology in the single-molecular nano-junctions through which the de Broglie wave propagates plays a crucial role in controlling the molecular conductance. The enhancement and reduction of the conductance due to constructive and destructive Quantum Interference (QI) in para and meta connected molecules respectively has already been well established. Herein, we investigated the influence of QI on spin transport in the molecular junctions containing organic radicals as magnetic centres. The role of the localized spins on the QI as well as on spin filtering capability is investigated employing density functional theory in combination with non-equilibrium Green's function (NEGF-DFT) techniques. Various organic radicals including nitroxide (NO), phenoxy (PO) and methyl (CH2) radicals attached to the central benzene ring of pentacene with different terminal connections (para and meta) to gold electrodes are examined. Due to more obvious QI effects, para connected pentacene is found to be more conductive than meta one. Surprisingly, on incorporating a radical centre, along with spin filtering, a significant quenching of QI effects is observed which manifests itself in such a way that the conductance of meta coupled radicals is found to be more than para by two orders of magnitude. The decoherence induced by radical centre is analysed and discussed in terms of spin-spin coupling of radical's unpaired electron with the tunneling electrons.<br>


2020 ◽  
Author(s):  
Ashima Bajaj ◽  
Prabhleen Kaur ◽  
Aakanksha Sud ◽  
Marco Berritta ◽  
Md. Ehesan Ali

The molecular topology in the single-molecular nano-junctions through which the de Broglie wave propagates plays a crucial role in controlling the molecular conductance. The enhancement and reduction of the conductance due to constructive and destructive Quantum Interference (QI) in para and meta connected molecules respectively has already been well established. Herein, we investigated the influence of QI on spin transport in the molecular junctions containing organic radicals as magnetic centres. The role of the localized spins on the QI as well as on spin filtering capability is investigated employing density functional theory in combination with non-equilibrium Green's function (NEGF-DFT) techniques. Various organic radicals including nitroxide (NO), phenoxy (PO) and methyl (CH2) radicals attached to the central benzene ring of pentacene with different terminal connections (para and meta) to gold electrodes are examined. Due to more obvious QI effects, para connected pentacene is found to be more conductive than meta one. Surprisingly, on incorporating a radical centre, along with spin filtering, a significant quenching of QI effects is observed which manifests itself in such a way that the conductance of meta coupled radicals is found to be more than para by two orders of magnitude. The decoherence induced by radical centre is analysed and discussed in terms of spin-spin coupling of radical's unpaired electron with the tunneling electrons.<br>


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