共查询到20条相似文献,搜索用时 15 毫秒
1.
We study the temperature T and the phase of the Josephson critical current I(Ф) by taking into account the roughness scattering effect at inerface in an f-wave superconductor (S)/Insulator layer (I)/f-wave superconductor (S) junction. It is found that the Josephson critical currents in f-wave Sir-wave S, the barrier strength and the roughness strength at inerface always suppress the Andreev reflection. When α=β, the phase dependence of the Josephson current I(Ф) between two f-wave S is predicted to be sin Ф; particularly, when a α≠ β, the phase dependence of the Josephson current I(Ф) between two f-wave superconductors is not predicted to be sin Ф and with the barrier strength increasing, the period of the I(Ф) turns decrease. 相似文献
2.
Solving the Bogoliubov-de Gennes
equation, the energy levels of bound states are obtained in the
ferromagnetic superconductor. The Josephson currents in a ferromagnetic superconductor/Insulator/d-wave superconductor junction are calculated as a function of the exchange
field, temperature, and insulating barrier strength. It is found
that the Josephson critical current is always suppressed by the
presence of exchange field h and depends on crystalline axis
orientation of d-wave superconductor. 相似文献
3.
通过计算具有铁磁绝缘层的双层f波超导体结中铁磁绝缘层的磁散射对直流Josephson电流的影响,研究了f波超导体(fS)/铁磁绝缘层(FI)/f波超导体(fS)结的直流Josephson电流与温度和结两侧相位差((?))之间的关系.研究表明:fS/FI/fS结界面的粗糙散射和磁散射总是抑制结中准粒子的Andreev反射,降低流过fS/FI/fS结的直流Josephson电流,且结的直流Josephson电流随相位差的变化曲线强烈依赖于f波超导体的晶轴方位角(α). 相似文献
4.
在 s波超导体 /铁磁绝缘层 / d波超导体 Josephson结 (s/ FI/ d)中 ,考虑结界面铁磁绝缘层的磁散射和粗糙散射情况下 ,运用 Bd G方程和 FT的电流公式计算准粒子的输运系数及 s/ FI/ d结的直流 Josephson电流与温度 T、结两侧的相位差之间的关系。研究表明 :结界面的磁散射和粗造散射均抑制结中准粒子的 Andreev反射 ,降低了流过 s/ FI/ d结的直流 Josephson电流 ,直流Josephson电流 I随温度 T、相位差φ的变化曲线强烈地依赖于 d波超导体的晶轴方位 相似文献
5.
LI Xiao-Wei 《理论物理通讯》2007,47(4):737-740
The Josephson currents in s-wave superconductor/ferromagnet insulator/p-wave superconductor(s/FI/p) junctions are calculated as a function of temperature and the phase taking into account the roughness scattering effect at interface. The phase dependence of the Josephson current I (φ) between s-wave and px-wave superconductor is predicted to be sin(2φ). The ferromagnet scattering effect, the barrier strength, and the roughness strength at interface suppress the dc currents in s/FI/p junction. 相似文献
6.
DONG Zheng-Chao 《理论物理通讯》2004,41(5):775-780
The tunneling spectroscopy and shot noise in ferromagnet/insulator/triplet-superconductor (FM/I/triplet-SC) structures are studied by taking into account the roughness interfacial barrier and exchange splitting in the FM. For the triplet-SC of
Sr2RuO4,
we consider two-dimensional f-wave order parameter symmetries having nodes within the RuO2
plane, which reasonably describe both thermodynamic and thermal conductivity data. It is shown that the ferromagnetic exchange splitting gives rise to a decrease in the differential
conductance, the average current, and the shot noise power, while the noise power-to-current ratio is increased; the interface roughness is found to lead to a decrease in the differential
conductance and the average current, and an increase in the noise power-to-current ratio. 相似文献
7.
在超导体铁磁体绝缘层超导体结(SFIS)中,运用BogoliubovdeGennes(BdG)方程和FurusakiTsukada(FT)电流公式,计算铁磁超导共存态的自洽方程和SFIS结中的直流Josephson电流.研究表明,铁磁超导态的磁交换能h对准粒子的Andreev反射有抑制作用,使得SFIS结中的直流Josephson电流随铁磁超导共存态的磁交换能h增大而减弱
关键词:
S/F-I-S结
铁磁超导态
直流Josephson电流 相似文献
8.
LI Xiao-Wei 《理论物理通讯》2009,(10):721-725
The Bogoliubov de Gennes equation is applied to the study of coherence effects in the ferromagnetic superconductor/insulator/normal metal/insulator/ferromagnetic/superconductor (FS/I/N/I/FS) junction. We calculated the Josephson current in FS/I/N/I/FS as a function of exchange field in ferromagnetic superconductor, temperature, and normal metal thickness. It is found that the Josephson critical current in FS/I/N/I/FS exhibits oscillations as a function of the length of normal metal. The exchange field always suppresses the Josephson critical current Ip for a parallel configuration of the magnetic moments of two ferromagnetic superconductor (FS) electrodes. In the antiparallel configuration, the Josephson critical current IAv at the minimum values of oscillation increases with the exchange field for strong barrier strength and at low temperatures. 相似文献
9.
LI Xiao-Wei 《理论物理通讯》2009,52(4):721-725
The Bogoliubov de Gennes equation is applied to the study ofcoherence effects in the ferromagnetic superconductor/insulator/normalmetal/insulator/ferromagnetic/superconductor (FS/I/N/I/FS) junction. We calculated the Josephson current in FS/I/N/I/FS as a function of exchange field in ferromagnetic superconductor, temperature, and normal metal thickness. It is found that the Josephson critical current in FS/I/N/I/FS exhibits oscillations as a function of the length of normal metal. The exchange field always suppresses the Josephson critical current Ip for a parallel configuration of the magnetic moments of two ferromagnetic superconductor (FS) electrodes. In the antiparallel configuration, the Josephson critical current IAp at the minimum values of oscillation increases with the exchange field for strong barrier strength and at low temperatures. 相似文献
10.
基于Bogoliubov-de Gennes方程和Blonder-Tinkham-Klapwijk理论研究了三维拓扑绝缘体基铁磁/各向异性f-波超导隧道结的Andreev反射,其中f-波超导体选取f1和f2-波两种配对势.研究发现,对于f1和f2波,铁磁体中的磁能隙可以增强传统的Andreev逆向反射,但对Andreev镜面反射有抑制作用;但随着施加在超导体顶部电极上的栅极电位的增加,两种类型的反射都会增强.通过改变磁能隙,可以调节两种反射在准粒子输运过程中占有优势的程度.这些结果提供了一种实验检测拓扑绝缘体薄膜中镜面Andreev反射的方法.此外,隧穿电导和散粒噪声谱的差异可用于区分f1和f2波配对势. 相似文献
11.
<正>The anisotropy of the dc Josephson current in the superconducting junctions of the p-wave equal spin pairing symmetry is theoretically investigated by the Furusaki-Tsukada-like formula.The current phase relations exhibit different oscillation periods and different phase shifts for the current along different directions,respectively. 相似文献
12.
SSeS超导结的约瑟夫逊效应 总被引:2,自引:2,他引:2
以推广的 Jacobson方法 ,从 Ginzburg- L andau方程出发 ,推导出了 SSe S超导结的直流约瑟夫逊效应 ,从而进一步求得了 SSe S超导结的临界电流与温度之间的关系 ,以及对结区厚度的依赖性 相似文献
13.
Zeeman effects on Josephson current in d-wave superconductor/d-wave superconductor junctions 下载免费PDF全文
This paper solves a self-consistent equation for the d-wave
superconducting gap and the effective exchange field in the
mean-field approximation, and studies the Zeeman effects on the
d-wave superconducting gap and thermodynamic potential. The Josephson
currents in the d-wave superconductor(S)/insulating layer(I)/d-wave S
junctions are calculated as a function of the temperature, exchange
field, and insulating barrier strength under a Zeeman magnetic field
on the two d-wave Ss. It is found that the Josephson critical
currents in d-wave S/d-wave S junction to a great extent depend on
the relative orientation of the effective exchange field of the two S
electrodes, and the crystal orientation of the d-wave S. The exchange
field under certain conditions can enhance the Josephson critical
current in a d-wave S/I/d-wave S junction. 相似文献
14.
We present an analytical result for the supercurrent across a superconductor/quantum-dot/superconductor junction. By converting the current integration into a special contour integral, we can express the current as a sum of the residues of poles. These poles are real and give a natural definition of the Andreev bound states. We also use the exact result to explain some features of the supercurrent transport behavior. 相似文献
15.
We present an analytical result for the supercurrent across a
superconductor/quantum-dot/superconductor junction. By converting the
current integration into a special contour integral, we can express the
current as a sum of the residues of poles. These poles are real and give a
natural definition of the Andreev bound states. We also use the exact result
to explain some features of the supercurrent transport behavior. 相似文献
16.
由Bogoliubov-de Gennes方程得到铁磁超导共存态(FS)的自洽方程,利用推广的Furusaki-Tsukada的电流公式计算了铁磁超导态/绝缘层/自旋三重态p波超导体(FS/I/p)结的直流Josephson电流随结的温度、相位差以及FS中磁交换能、结界面的势垒散射强度的变化关系.研究表明:FS中磁交换能、结界面的势垒散射均抑制FS/I/p结的直流Josephson电流.当自旋三重态超导体具有px波配对势时,自旋三重态超导体结的直流Josephson电流随结两侧相位差的振荡周期是π.
关键词:
铁磁超导态
自旋三重态超导体
p波超导体
直流Josephson电流 相似文献
17.
LI Xiao-Wei 《理论物理通讯》2006,45(2):369-372
In this paper, the superconducting order parameter and the energy spectrum of the Bogoliubov excitations are obtained from the Bogoliubov-de Gennes (BdG) equation for a ferromagnetic
superconductor (FS). Taking into account the rough interface
scattering effect, we calculate the shot noise and the differential
conductance of the normal-metal insulator ferromagnetic superconductor
junction. It is shown that the exchange energy Eh in FS can lead to splitting of the differential
shot noise peaks and the conductance peaks. The energy difference between the two splitting peaks is equal to
2Eh. The rough interface scattering strength
results in descent of conductance peaks and the shot noise-to-current ratio but increases the shot noise. 相似文献
18.
Yang Li Xu Wei-wei Ye Su-li Guo Da-yuan You Li-xing Wu Pei-heng 《Frontiers of Physics in China》2006,1(1):122-124
During the fabrication of intrinsic Josephson junctions (IJJs) with Bi2Sr2CaCu2O8+δ
(BSCCO) single crystals, the superconductivity of the surface Cu-O layer is degraded because of a deposited metal film on
top of the stack. Thus, the characteristics of the surface junction consisting of the surface Cu-O double layers remarkably
differ from those of the junctions deep in the stack, which will be referred to as ordinary IJJs. The electrical transport
characteristics of the surface junction, such as I-V, I
c′-T, and R-T, show that the critical temperature T
c′ of the surface junction is always lower than that of ordinary IJJs, and that the change of its critical current I
c′ with temperature is different from that of ordinary IIJs. Furthermore, by shunting the surface junction resistively, we
are able to observe the AC Josephson effect at 3-mm waveband.
Translated from Chinese Journal of Low Temperature Physics, 2005, 27(2) (in Chinese) 相似文献
19.
通过求解磁性d波超导中的能隙和磁交换能的自洽方程, 研究磁性d波超导/铁磁/磁性d波超导结中的约瑟夫森电流. 计算结果表明: 1)临界电流随中间的铁磁层厚度呈现出两种不同周期的振荡混合, 通过增强铁磁层中的磁交换能q0和铁磁/磁性d波超导界面处的势垒强度z0, 短周期分量可从长周期中分离出来, 反之, 通过降低q0和z0, 长周期分量可从短周期中分离出来; 2)在两边磁性d波超导的磁化方向取平行时, 在取一些特定的铁磁层厚度下, 磁性d波超导中的磁交换能可增强系统的临界电流.
关键词:
磁性d波超导体
铁磁体
约瑟夫森电流 相似文献
20.
LI Jing-Hui 《理论物理通讯》2009,51(5):853-856
In the paper, we study a super-conducting junctions device subject to an input periodic signal and a constant force. It is shown that, for this device, we can get current reversals for the current of the electron pairs versus the frequency of the periodic signal and negative conductance for the current of the electron pairs as a function of the constant force. 相似文献