作者机构：
[Zhao, Chen-Chen; Tan, Shi-Hua; Peng, Xiao-Fang; Wang, Xin-Jun; Tan, SH; Wang, XJ] Cent South Univ Forestry & Technol, Inst Math & Phys, Changsha 410004, Hunan, Peoples R China.;[Long, Mengqiu] Cent S Univ, Sch Phys & Elect, Changsha 410083, Hunan, Peoples R China.
通讯机构：
[Tan, SH; Wang, XJ] C;Cent South Univ Forestry & Technol, Inst Math & Phys, Changsha 410004, Hunan, Peoples R China.
关键词：
Perfect spin filter;Perfect type transformation;Spin transport;sn-phthalocyanine
摘要：
We have investigated the electronic transport properties of Sn-phthalocyanine (SnPc) by using nonequilibrium Green's functions in combination with the density functional theory. The results show that, the spin-up/spin-down PDOS peak at 0.74 eV of SnPc will firstly move toward to the Fermi level and then be away from the Feimi level as the Sn atom is pulled out. A transform from spin-down filter to spin-up filter can be observed in parallel configuration due to spin flipping introduced by structural reorganization. While in anti-parallel configuration, the band structures of the two electrodes will play the dominant role in the electron properties of SnPc. The spin filter type conversion can be realized by pulling the Sn atom out of the SnPc or flipping the magnetic field of one electrode. (C) 2017 Elsevier B.V. All rights reserved.
摘要：
We present a computational study of the plasmon resonances in a periodic square coaxial hole array in a graphene sheet, which consists of a square hole array and a square strip array. According to charge oscillation picture, we find that a new plasmon mode, which locates on the edges of square hole along the polarization direction of incident light, emerges in our proposed structure. Two hybridized plasmon resonance modes (i.e., symmetric and asymmetric plasmon resonance modes) are formed due to two different manners of coupling between the new plasmon mode of square hole and the plasmon mode of square strip. The two plasmon resonance modes can be tuned over a wide wavelength range by a small change in the chemical potential of graphene. Furthermore, the two plasmon resonances can also be controlled by changing L
x
and L
y
(which are the strip offsets from the hole center perpendicular and parallel to the polarization direction of incident light, respectively), originating from the change in the strength of electromagnetic coupling between square hole and square strip. Our study gives an insight into the physical mechanism of plasmon resonances in square graphene coaxial hole array, and our findings will be useful for designing graphene-based plasmonic devices and metamaterials.
期刊：
International Journal of Modern Physics B,2016年30(16):1650088 ISSN：0217-9792
通讯作者：
He, Meng-Dong
作者机构：
[Peng, Yu-Xiang; Li, Ze-Jun; Wang, Kai-Jun; Liu, Ling-Hong; Wang, Lei; Wang, Xin-Jun; He, Meng-Dong; Li, Jian-Bo] Cent South Univ Forestry & Technol, Inst Math & Phys, Changsha 410004, Hunan, Peoples R China.;[Xu, Liang] Hunan Univ, Coll Mat Sci & Engn, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[He, Meng-Dong] C;Cent South Univ Forestry & Technol, Inst Math & Phys, Changsha 410004, Hunan, Peoples R China.
关键词：
Surface plasmon polaritons;plasmon resonance energy transfer;metallic grating;reduced cytochrome c molecule
摘要：
We investigate the transmission characteristics of a one-dimensional metallic grating covered by a reduced cytochrome (Cyt) c molecule layer by using the finite-difference time-domain (FDTD) method. It is found that the introduction of reduced Cyt c molecule layer leads to a transmission dip due to the plasmon resonance energy transfer (PRET) from metallic grating to Cyt c molecules. The transmission dip depth can be controlled by the period of metallic grating, the width and length of slit, and the Cyt c molecule layer number, while the transmission dip wavelength is unchanged with these parameters. The findings expand our understanding of the PRET phenomenon and have potential applications in molecule identification and detection.
通讯机构：
[He, Meng-Dong] C;Cent South Univ Forestry & Technol, Inst Math & Phys, Changsha 410004, Hunan, Peoples R China.
关键词：
Localized surface plasmon resonance;Plasmon resonance energy transfer;Metallic nanoparticle array;Reduced cytochrome c molecule
摘要：
We investigate the optical properties of a metallic nanoparticle array covered by a reduced cytochrome (Cyt) c molecule layer by using the finite-difference time-domain method. As the wavelength of the surface plasmon resonance of metallic nanoparticle array matches with that of the absorption peak of reduced Cyt c molecules, a pronounced spectral dip forms in extinction spectrum due to the plasmon resonance energy transfer from metallic nanoparticles to Cyt c molecules. The depth of extinction dip can be controlled by the length and width of metallic nanoparticle, the grating constant, and the Cyt c molecule layer number, though the position of extinction dip is unchanged with these parameters. The findings may find applications in molecule identification and detection.
摘要：
In this paper, we investigate the plasmon resonances in a stacked pair of periodic graphene hole arrays by using charge oscillation picture. It is found that the plasmon resonances can be controlled by changing the longitudinal interval G between two arrays, and the lateral displacements L
x
and L
y
, which are parallel and perpendicular to the polarization direction of the incident light, respectively. The plasmon resonance can be tuned over a wide wavelength range by a small change of G due to its influence on the strength of electromagnetic coupling between two arrays. The lateral displacement L
x
causes new plasmon resonance modes, originating from the appearance of new electromagnetic coupling manners, while the lateral displacement L
y
leads to the splitting of plasmon resonance mode, which results from two different electromagnetic coupling manners. Our study gives an insight into the physical mechanism of plasmon resonances in two graphene hole arrays, and our findings may hold great promise in designing graphene-based plasmonic devices and metamaterials.
期刊：
Optical and Quantum Electronics,2014年46(11):1425-1433 ISSN：0306-8919
通讯作者：
Wang, Xin-Jun
作者机构：
[Ma, Wang-Guo; Wang, Xin-Jun; He, Meng-Dong] Cent South Univ Forestry & Technol, Inst Math & Phys, Changsha 410004, Hunan, Peoples R China.;[Liu, Jian-Qiang] Jiujiang Univ, Coll Sci, Jiujiang 332005, Peoples R China.
通讯机构：
[Wang, Xin-Jun] C;Cent South Univ Forestry & Technol, Inst Math & Phys, Changsha 410004, Hunan, Peoples R China.
关键词：
Electromagnetic transmission;Metallic nanoslit with microcavity;Surface plasmon polaritons
摘要：
In this paper, we explore the electromagnetic transmission through a vertical metallic nanoslit with a horizontal microcavity. The introduction of microcavity gives rise to the changes of slit transmission spectrum in the number and amplitude of transmission peak and dip, owing to the electromagnetic coupling between slit and microcavity. The transmission through the slit with microcavity strongly depends on whether the isolated slit is in resonance or not, and the microcavity resonance is an additional factor that influences the transmission. The transmission spectrum can be adjusted by changing the opening position of slit, and the slit depth, the width and depth of microcavity. Our results are analysed and discussed from the view of Fano resonance. These results may be of value in tuning electromagnetic wave in subwavelength optics and designing plasmonic devices based on composite metallic nanoslit structures.
摘要：
In this paper, we investigate low-temperature thermal conductance in three-dimensional nanowire embedded with phonon cavity based on the full scalar model of elasticity. The results show that at very low temperatures, the cavity can enhance the thermal conductance in certain lateral-width range, just as the constructive coupling of more phonon-modes excited in the cavity with modes in the transport region. At higher temperatures, however, the scattering of more interfaces formed from the cavity become a dominant factor to suppress the phonon transmission. Moreover, it is found that while the material in the cavity is substituted for the material with higher sound velocity than that in the transport region, the thermal conductance is also enhanced.
摘要：
We study the ballistic phonon transport and thermal conductance of six low-lying vibration modes in quantum wire modulated with quantum dot at low temperatures. A comparative analysis is made among the six vibrational modes. The results show that the transmission rates of the six vibrational modes relative to reduced frequency display periodic or quasi-periodic oscillatory behavior. Among the four acoustic modes, the thermal conductance contributed by the torsional mode is the smallest, and the thermal conductances of other acoustic modes have adjacent values. It is also found that the thermal conductance of the optical mode increases from zero monotonously. Moreover, the total thermal conductance in concavity-shaped quantum structure is lower than that in convexity-shaped quantum structure. These thermal conductance values can be adjusted by changing the structural parameters of the quantum dot. (C) 2014 Elsevier B.V. All rights reserved.
