scholarly journals Spin Transport Properties in 1D DNA and Electrically Doped Iron Quantum Dot Organo-metallic Junction: A First Principle Paradigm

Author(s):  
Debarati Dey Roy ◽  
Pradipta Roy ◽  
Debashis De

Abstract The DNA sensor has emerged as strong candidates for next generation ultra low power application due to its self assemble technique. Non-Equilibrium Green’s Function (NEGF) along with Density Functional Theory (DFT) based First Principle approach is used in investigation of spin transport properties along with quantum scattering transmission characteristics of DNA sensor via Iron (Fe) quantum dots (QD) electrodes at room temperature. Electrically doped Fe QD plays an important role in spin transport mechanism. This electrical doping concentration and weak coupling strength between DNA and Fe QD organo-metallic junction effect into the tunneling contact resistance (TCR) along with quantum-ballistic transmission and junction conductivity of parallel and anti-parallel configuration of this analytical model representation. It has been observed that higher current has been achieved for parallel configuration when compare with anti-parallel configuration at same bias voltage. This voltage-current characteristic is significantly modulated due to the electrical doping effect. This spin transport property shows that this system can well perform for anti parallel configuration. High tunnel organo-metallic resistance approximately 99.9% is observed even at 0V bias voltage. TOMCR remains large at upper bias voltage .

2014 ◽  
Vol 543-547 ◽  
pp. 3947-3950
Author(s):  
Shi Wei Ren

In this paper, the spin transport properties of the coblt dimers parrallel to the transport direction and perpendicular to ransprot direction are investigated by using the first principle analysis. Calculation shows that both the coblt dimers parrallel to the transport direction and perpendicular to ransprot direction give obvious spin polarized density of states and current. It is found that the dimer parrallel to the transport direction have larger spin polarization current.The spin polarized efficiency for the parrallel dimer increase steadily with the increase of the bias voltage. But the the spin polarization for the transverse dimer changes greatly.


Author(s):  
Yaoxing Sun ◽  
Bei Zhang ◽  
shidong zhang ◽  
Dan Zhang ◽  
Jiwei Dong ◽  
...  

Based on MoC2 nanoribbons and poly-(terphenylene-butadiynylene) (PTB) molecules, we designed MoC2-PTB molecular spintronic devices and investigated their spin-dependent electron transport properties by using spin-polarized density functional theory and non-equilibrium Green's...


Micromachines ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 26
Author(s):  
Baorui Huang ◽  
Fuchun Zhang ◽  
Yanning Yang ◽  
Zhiyong Zhang

The two-probe device of nanorod-coupled gold electrodes is constructed based on the triangular zinc oxide (ZnO) nanorod. The length-dependent electronic transport properties of the ZnO nanorod was studied by density functional theory (DFT) with the non-equilibrium Green’s function (NEGF). Our results show that the current of devices decreases with increasing length of the ZnO nanorod at the same bias voltage. Metal-like behavior for the short nanorod was observed under small bias voltage due to the interface state between gold and the ZnO nanorod. However, the influence of the interface on the device was negligible under the condition that the length of the ZnO nanorod increases. Moreover, the rectification behavior was observed for the longer ZnO nanorod, which was analyzed from the transmission spectra and molecular-projected self-consistent Hamiltonian (MPSH) states. Our results indicate that the ZnO nanorod would have potential applications in electronic-integrated devices.


2016 ◽  
Vol 30 (23) ◽  
pp. 1650301
Author(s):  
Chunlong Xu ◽  
Zhen Wang ◽  
Lei Wang ◽  
Gang Shi ◽  
Zhaoyang Hou ◽  
...  

Spin-dependent transport properties of Fe3O4 spheres with diameters from 200 nm to 900 nm have been investigated and polyethylene glycol (PEG) exists on the surface of Fe3O4 particles. The nonlinear I–V curve became obvious with the increase of Fe3O4 diameter, which indicated the tunneling barrier height decreases with the increasing diameter. The magnetoresistance (MR) can reach −13% with an applied low field of 0.2 T at room temperature. With the diameter increase, the MR decreases and the required applied field increases. Moreover, the decrease of MR with the bias voltage increase can be attributed to the spin-dependent tunneling effect through the insulating surface layer of Fe3O4 and PEG.


2015 ◽  
Vol 17 (17) ◽  
pp. 11292-11300 ◽  
Author(s):  
Dongqing Zou ◽  
Bin Cui ◽  
Xiangru Kong ◽  
Wenkai Zhao ◽  
Jingfen Zhao ◽  
...  

A series of n-acene–graphene (n = 3, 4, 5, 6) devices, in which n-acene molecules are sandwiched between two zigzag graphene nanoribbon (ZGNR) electrodes, are modeled through the spin polarized density functional theory combined with the non-equilibrium Green's function technique.


Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1342 ◽  
Author(s):  
Zongbin Chen ◽  
Tingzhou Li ◽  
Tie Yang ◽  
Heju Xu ◽  
Rabah Khenata ◽  
...  

Spin-gapless semiconductors (SGSs) with Dirac-like band crossings may exhibit massless fermions and dissipationless transport properties. In this study, by applying the density functional theory, novel multiple linear-type spin-gapless semiconducting band structures were found in a synthesized R 3 − c -type bulk PdF3 compound, which has potential applications in ultra-fast and ultra-low power spintronic devices. The effects of spin-orbit coupling and on-site Coulomb interaction were determined for the bulk material in this study. To explore the potential applications in spintronic devices, we also performed first-principles combined with the non-equilibrium Green’s function for the PdF3/Ga2O3/PdF3 magnetic tunnel junction (MTJ). The results suggested that this MTJ exhibits perfect spin filtering and high tunnel magnetoresistance (~5.04 × 107).


Author(s):  
Anil Kumar Singh ◽  
Sudhanshu Choudhary

Spin dependent quantum transport properties in twisted carbon nanotube and stretched carbon nanotube are calculated using density functional theory (DFT) and non-equilibrium green’s function (NEGF) formulation. Twisting and stretching have no effect on spin transport in CNTs at low bias voltages. However, at high bias voltages the effects are significant. Stretching restricts any spin-up current in antiparallel configuration (APC) which results in higher magneto resistance (MR). Twisting allows spin-up current almost equivalent to the pristine CNT case resulting in lower MR. High spin filtration is observed in PC and APC for pristine, stretched and twisted structures at all applied voltages. In APC, at low voltages spin filtration in stretched CNT is higher than in pristine and twisted ones with pristine giving higher spin filtration than twisted CNT.


RSC Advances ◽  
2015 ◽  
Vol 5 (86) ◽  
pp. 70682-70688 ◽  
Author(s):  
Xiangru Kong ◽  
Dongqing Zou ◽  
Hui Wang ◽  
Xiaohui Jiang ◽  
Sun Yin ◽  
...  

By using non-equilibrium Green’s functions (NEGF) and DFT, we investigate the spin-dependent electronic transport properties of two heterojunctions based on zigzag-edged graphene nanoribbons and graphitic carbon nitride nanoribbons.


2018 ◽  
Vol 32 (29) ◽  
pp. 1850326
Author(s):  
Wenhua Liu ◽  
Wei Hu ◽  
Yan Liang ◽  
Qinghua Zhou ◽  
Kerong He ◽  
...  

In this paper, we have studied the electronic transport behavior of the system formed by the Al2N2 cluster and the Al(100)-3 × 3 electrodes by using the first principle based on nonequilibrium Green’s function (NEGF). The total energies and the equilibrium conductances of the system are calculated at different distances between the clusters and the electrodes, and the results show that the equilibrium conductance is 0.1335 G0 and the total energy is the lowest at d = 2.8 Å (d means the distance between the Al2N2 cluster and the electrodes). When d increases, the equilibrium conductance decreases. In the bias voltage range of [−1 V, 1 V], the system has the electrical characteristics similar to the metal when the d is 2.0, 2.4, 2.8, 3.2 and 3.5 Å.


Sign in / Sign up

Export Citation Format

Share Document