检索结果-南通市图书馆

Effects of Conduction Electron Band Structure on Transport of Quantum Dot Systems

Chinese Physics Letters 2003年第5期20卷 717-720页

作者： YANGKai-Hua SONGBo TIANGuang-shan WANGYu-Peng hanru-shan hanru-Qi InstituteforMicroelectronics PekingUniversityBeijing100871 TechnicalInstituteofPhysicsandChemistry ChineseAcademyofSciencesBeijing100080 SchoolofPhysics PekingUniversityBeijing100871 InstituteofPhysicsandCenterforCondensedMatterPhysics ChineseAcademyofSciencesBeijing100080

We study the effects of the energy band structure of conduction-electron on the transport properties of an interacting quantum dot system. By applying the nonequilibrium Keldysh Green function technique, we show that the finite width of electron band in leads causes the negative differential conductance in some regions of the applied voltage. We also show that the van Hove singularities in the density of states of conduction-electron do not qualitatively change the differential conductance of the system, and hence can be safely ignored. Therefore, the wide band approximation used in the previous investigations is partially justified.

关键词：量子通信体系相互作用电子传输电子结构量子点

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A Rigorous Investigation on the Ground State of the Penson—Kolb Model

引用

Communications in Theoretical Physics 2003年第5期39卷 607-612页

作者： YANGKai-Hua TIANGuang-shan hanru-Qi InstituteofMicroelectronics PekingUniversityBeijing100871China SchoolofPhysics PekingUniversityBeijing100871CHina SchoolofPhysics PekingUniversityBeijing100871CHina InstituteofMicroelectronics PekingUniversityBeijing100871China

By using either numerical calculations or analytical methods, such as the bosonization technique, the ground state of the Penson-Kolb model has been previously studied by several groups. Some physicists argued that, as far as the existence of superconductivity in this model is concerned, it is canonically equivalent to the negative-U Hubbard ***, others did not agree. In the present paper, we shall investigate this model by an independent and rigorous approach. We show that the ground state of the Penson-Kolb model is nondegenerate and has a nonvanishing overlap with the ground state of the negative-U Hubbard model. Furthermore, we also show that the ground states of both the models have the same good quantum numbers and may have superconducting long-range order at the same momentum q ＝ 0. Our results support the equivalence between these models.

关键词：超导电性 Penson-Kolb模型强相关电子系统 “负-U Hubbard模型”

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Binding Energy, Spin－Excitation Gap, and Charged Gap in the Boson－Fermion Model

引用

Communications in Theoretical Physics 2003年第2X期40卷 215-220页

作者： YANGKai-Hua Guang-shan hanru-Qi InstituteofMicroelectronics PekingUniversityBeijing100871China SchoolofPhysics PekingUniversityBeijing100871China

In this paper, by applying a simplified version of Lieb's spin-reflection-positivity method, which was recently developed by one of us [G.S. Tian and J.G. Wang, J. Phys. A: Math. Gen. 35 (2002) 941], we investigate some general properties of the boeon-fermion Hamiltonlan, which has been widely used as a phenomenological model to describe the real-space pairing of electrons. On a mathematically rigorous basis, we prove that for either negative or positive couping V, which represents the spontaneous decay and recombination process between boson and fermion in the model, the pairing energy of electrons is nonzero. Furthermore, we also show that the spin-excitation gap of the boson-fermion Hamiltonian is always larger than its charged gap, as predicted by the pre-palred electron theory.

关键词：结合能 Boson-Fermion模型励磁间隙带电间隙电子对高温超导体超导电性

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：