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复合粒子的置换对称性
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作者 徐烈民 《职大学报》 1995年第3期42-44,共3页
本文讨论由相同的粒子所组成的复合粒子的置换对称性。在复合粒子的体积较容器的体积为很小的情形和各个复合粒子相应的波包没有重迭,所以似乎不必考虑它们之间的置换对称性,可是在凝聚态物理中却很强调复合粒子是玻色子或是费米子的问... 本文讨论由相同的粒子所组成的复合粒子的置换对称性。在复合粒子的体积较容器的体积为很小的情形和各个复合粒子相应的波包没有重迭,所以似乎不必考虑它们之间的置换对称性,可是在凝聚态物理中却很强调复合粒子是玻色子或是费米子的问题,也就是说必须要考虑各个复合粒子的置换对称性。这就出现一个佯谬,我们将复合粒子这个多体系统的质心坐标分出,质心运动与一个平面波相应,各个粒子的运动平面波是重迭的,因此必须考虑到置换性。 展开更多
关键词 复合粒子置换对称性 波包重迭 玻色子和费米子 质心运动
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拓扑绝缘体中粒子-空穴对称性保护的新奇量子态
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作者 屠威 吴亚杰 《西安工业大学学报》 CAS 2022年第6期547-551,558,共6页
为了探究拓扑绝缘体中非拓扑缺陷对诱导零模态产生的影响,文中在粒子-空穴性对称的拓扑绝缘体中加入非拓扑缺陷(格点空位),经数值严格对角化,得出系统能级分布和粒子态密度分布,并利用陈数计算系统的全局相图。研究发现:非拓扑缺陷同样... 为了探究拓扑绝缘体中非拓扑缺陷对诱导零模态产生的影响,文中在粒子-空穴性对称的拓扑绝缘体中加入非拓扑缺陷(格点空位),经数值严格对角化,得出系统能级分布和粒子态密度分布,并利用陈数计算系统的全局相图。研究发现:非拓扑缺陷同样会诱导“规范不变”的零模态,并且具有非平庸的物理性质;当体系中存在奇数个格点空位时,总会有一个零能束缚态出现,而体系中存在偶数个格点空位时,局域束缚态具有有限能量;系统的粒子空穴对称性被破坏后,单格点空位诱导的零能态变为有限能量的束缚态;在无自旋霍尔丹模型中,诱导的零模态携带e/2分数电荷;在自旋的霍尔丹模型中,诱导的零模态携带1/2自旋磁矩。 展开更多
关键词 拓扑绝缘体 粒子空穴对称性 格点空位 零模
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超对称性研究回顾(英文)
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作者 张东海 王剑波 《山西师范大学学报(自然科学版)》 2000年第3期28-53,共26页
本文在讨论标准模型的成就与不足的基础上对近年来超对称性的研究进行了回顾 .如果在弱电标度下存在超对称性粒子 ,则它们应该在 LHC上得到证实 ,然而超对称性粒子质量的确定是非常困难的 .本文对 LHC各个点上如何从实验观察到的各种分... 本文在讨论标准模型的成就与不足的基础上对近年来超对称性的研究进行了回顾 .如果在弱电标度下存在超对称性粒子 ,则它们应该在 LHC上得到证实 ,然而超对称性粒子质量的确定是非常困难的 .本文对 LHC各个点上如何从实验观察到的各种分布精确地确定超对称性粒子的质量及衰变分支比的方法进行了讨论 . 展开更多
关键词 对称性 超引力 对称性粒子 粒子物理
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低对称性SiO_2/Ag核壳复合纳米结构的银镜反应制备及表面增强拉曼散射活性研究 被引量:2
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作者 徐进之 满石清 刘应亮 《材料导报》 EI CAS CSCD 北大核心 2011年第12期112-115,共4页
利用银镜反应在自组装的SiO2纳米粒子单层膜上制备了低对称性的SiO2/Ag核壳复合纳米结构。通过透射电镜(TEM)、扫描电镜(SEM)和紫外-可见分光光度计(UV-Vis)对核壳复合纳米结构的表面形貌和光学性质进行了表征。以亚甲基蓝作为探针分子... 利用银镜反应在自组装的SiO2纳米粒子单层膜上制备了低对称性的SiO2/Ag核壳复合纳米结构。通过透射电镜(TEM)、扫描电镜(SEM)和紫外-可见分光光度计(UV-Vis)对核壳复合纳米结构的表面形貌和光学性质进行了表征。以亚甲基蓝作为探针分子,研究了低对称性SiO2/Ag核壳复合纳米结构的表面增强拉曼散射(SERS)活性。 展开更多
关键词 SIO2微球 银镜反应 对称性银纳米粒子 表面等离子共振
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1964年北京科学讨论会的初步研究——以两篇中国粒子物理报告为例
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作者 张辉 尹晓冬 段菲菲 《自然科学史研究》 CSSCI CSCD 北大核心 2017年第4期548-562,共15页
文章首先叙述了1964年北京科学讨论会上物理天文组的筹备、组织与召开情况;进而对中国粒子物理学家的报告,特别是戴元本关于雷其极点和高崇寿关于粒子对称性的报告进行初步研究,并介绍了相关讨论交流的情况。通过对粒子物理学史的相关梳... 文章首先叙述了1964年北京科学讨论会上物理天文组的筹备、组织与召开情况;进而对中国粒子物理学家的报告,特别是戴元本关于雷其极点和高崇寿关于粒子对称性的报告进行初步研究,并介绍了相关讨论交流的情况。通过对粒子物理学史的相关梳理,表明戴元本和高崇寿的研究曾一度追赶上了世界前沿,并取得一些成就。这些报告及相关研究反映出新中国成立最初十几年粒子物理学的进展,同时也从这一侧面使我们了解北京科学讨论会的历史面貌。 展开更多
关键词 北京科学讨论会 雷其极点 粒子对称性
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“高温”超导机制研究获突破
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《中国科技产业》 1995年第3期34-34,共1页
“高温”超导机制研究获突破美国国际商用机器公司下属沃森研究中;心的科学家在1月19日出版的《自然》杂志上发表文章说,他们对“高温”超导机制的研究取得了重大突破。新发现涉及制作成环形的“高温”超导体内的磁单极子。运用一... “高温”超导机制研究获突破美国国际商用机器公司下属沃森研究中;心的科学家在1月19日出版的《自然》杂志上发表文章说,他们对“高温”超导机制的研究取得了重大突破。新发现涉及制作成环形的“高温”超导体内的磁单极子。运用一种被称为SQUID扫描显微镜的特殊... 展开更多
关键词 磁单极子 超导现象 “高温”超导体 应用前景 粒子对称性 临界温度
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Unsymmetrical Quantum Key Distribution Using Tripartite Entanglement 被引量:1
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作者 XIONG Jin ZHANG Zhe-Shen +2 位作者 ZHOU Nan-Run PENG Jin-Ye ZENG Gui-Hua 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第3期441-445,共5页
An unsymmetrical quantum key distribution protocol is proposed, in which Greenherger-Horne-Zeilinger (GHZ) triplet states are used to obtain the secret key. Except the lost qubits due to the unperfectness of the phy... An unsymmetrical quantum key distribution protocol is proposed, in which Greenherger-Horne-Zeilinger (GHZ) triplet states are used to obtain the secret key. Except the lost qubits due to the unperfectness of the physical devices, the unsymmetrical characteristic makes all transmitted qubits useful. This leads to:an excellent efficiency, which reaches 100% in an ideal case. The 'security is studied from the aspect of information theory. By using the correlation of the GHZ tripartite entanglement state, eavesdropping can be easily checked out, which indicates that the presented protocol is more secure. 展开更多
关键词 unsymmetrical quantum key distribution GHZ triplet states
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Supersymmetric Quantum Mechanics and SUSY Dependent SU(2) Symmetry for a Spin-1/2 Charged Particle in a Magnetic Field
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作者 JIA Wen-Zhi WANG Shun-Jin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第8期335-340,共6页
We find that in a supersymmetric quantum mechanics (SUSY QM) system, in addition to supersymmetric algebra, an associated SU(2) algebra can be obtained by using semiunitary (SUT) operator and projection operator... We find that in a supersymmetric quantum mechanics (SUSY QM) system, in addition to supersymmetric algebra, an associated SU(2) algebra can be obtained by using semiunitary (SUT) operator and projection operator, and the relevant constants of motion can be constructed. Two typical quantum systems are investigated as examples to demonstrate the above finding. The first example is the quantum system of a nonrelativistic charged particle moving in x-y plane and coupled to a magnetic field along z-axis. The second example is provided with the Dirac particle in a magnetic field. Similarly there exists an SUτ(2) SUσ(2) symmetry in the context of the relativistic Pauli Hamilt onian squared. We show that there exists also an SU(2) symmetry associated with the supersvmmetrv of the Dirac particle. 展开更多
关键词 supersymmetric quantum mechanics Dirac equation semi-unitary transformation
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Ωω States in a Chiral Quark Model
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作者 WANG Wen-Ling HUANG Fei +2 位作者 ZHANG Zong-Ye YU You-Wen LIU Feng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第4X期695-698,共4页
The structures of Ωω states with spin-parity JP= 5/2^-, 3/2^-, and 1/2^- are dynamically studied in both the chlral SU(3) quark model and the extended chiral SU(3) quark model by solving a resonating group meth... The structures of Ωω states with spin-parity JP= 5/2^-, 3/2^-, and 1/2^- are dynamically studied in both the chlral SU(3) quark model and the extended chiral SU(3) quark model by solving a resonating group method (RGM) equation. The model parameters are taken from our previous work, which gave a satisfactory description of the energies of the baryon ground states, the binding energy of the deuteron, the nucleon-nucleon (NN) scattering phase shifts, and the hyperon-nucleon (YN) cross sections. The calculated results show that the Ωω state has an attractive interaction, and in the extended chiral SU(3) quark model such attraction can make for a Ωω quasi-bound state with spin-parity JP = 3/2^- or 5/2^- and the binding energy of about several MeV. 展开更多
关键词 Ωω quasi-bound states quark model chiral symmetry
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Twisted Duality Symmetry and Integrability of Hybrid Superstring on AdS2 × S^2
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作者 XIE Xiao-Ning 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第4X期680-684,共5页
In this paper, we show that there exists a twisted duality symmetry between the Maurer-Cartan equations and the equations of motion in the hybrid formalism for the type liB superstring in an AdS2 ×S2 background w... In this paper, we show that there exists a twisted duality symmetry between the Maurer-Cartan equations and the equations of motion in the hybrid formalism for the type liB superstring in an AdS2 ×S2 background with Ramond-Ramond flux. As a result, from the twisted duality transformation, we construct the Lax connection with the spectral parameter, which ensures the integrability of the system. 展开更多
关键词 hybrid superstring twisted duality symmetry Lax connection INTEGRABILITY
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Quark Condensate in the Strange Matter
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作者 LU-Chang-Fang LUXiao-LU 《Communications in Theoretical Physics》 SCIE CAS CSCD 2003年第5期593-596,共4页
In a nonlinear chiral SU(3) framework, we investigate the quark condensate in the strange matter including and Λ, making use of chiral symmetry spontaneous breaking Lagrangian and mean-field approximation. The resul... In a nonlinear chiral SU(3) framework, we investigate the quark condensate in the strange matter including and Λ, making use of chiral symmetry spontaneous breaking Lagrangian and mean-field approximation. The results show that the chiral symmetry is restored partially when the strange matter density increases and that plays a very important role in the strange matter which may approach the constituents of the neutron stars. In addition, we can find that the strange matter density where the π-condensate emerges leads to the ratio of the nucleon number to baryon number. 展开更多
关键词 quark condensate chiral symmetry spontaneous breaking Lagrangian Hellmann-Feynman theory
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Selection rules of electromagnetic transitions for chirality-parity violation in atomic nuclei 被引量:2
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作者 Yuanyuan Wang Xinhui Wu +2 位作者 Shuangquan Zhang Pengwei Zhao Jie Meng 《Science Bulletin》 SCIE EI CSCD 2020年第23期2001-2006,M0004,共7页
The nuclear Chirality-Parity(ChP) violation, a simultaneous breaking of chiral and reflection symmetries in the intrinsic frame, is investigated with a reflection-asymmetric triaxial particle rotor model. A new symmet... The nuclear Chirality-Parity(ChP) violation, a simultaneous breaking of chiral and reflection symmetries in the intrinsic frame, is investigated with a reflection-asymmetric triaxial particle rotor model. A new symmetry for an ideal ChP violation system is found and the corresponding selection rules of the electromagnetic transitions are derived. The fingerprints for the ChP violation including the nearly degenerate quartet bands and the selection rules of the electromagnetic transitions are provided. These fingerprints are examined for ChP quartet bands by taking a two-j shell h11/2 and d5/2 with typical energy spacing for A = 130 nuclei. 展开更多
关键词 Chiture Chiplex Spontaneously symmetry breaking Selection rules of electromagnetic transitions
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Increased rigidly triaxial deformations in neutron-rich Mo, Ru isotopes
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作者 WuYang Liang ChangFeng Jiao +1 位作者 FuRong Xu XiMing Fu 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2016年第9期59-63,共5页
Pairing-deformation-frequency self-consistent cranking Woods-Saxon model is employed to investigate the triaxiality in the ground states of the neutron-rich even-even Mo, Ru isotopes. Deformation evolutions and transi... Pairing-deformation-frequency self-consistent cranking Woods-Saxon model is employed to investigate the triaxiality in the ground states of the neutron-rich even-even Mo, Ru isotopes. Deformation evolutions and transition probabilities have been studied, giving the triaxial shapes in their ground states. The kinematic moments of inertia have been calculated to illustrate the gradually rigid deformation. To understand the origin of the asymmetry shape in this region, we analyze the evolution of single-particle orbits with changing 3, deformation. The present calculations reveal the importance of the triaxial deformation in describing not only static property, but also rotational behaviors in this mass region, providing significant probes into the shell structure around. 展开更多
关键词 γ deformation transition probability moments of inertia
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Current Reversals of an Underdamped Brownian Particle in an Asymmetric Deformable Potential
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作者 Chun-Chun Cai Jian-Li Liu +1 位作者 Hao Chen Feng-Guo Li 《Communications in Theoretical Physics》 SCIE CAS CSCD 2018年第3期266-270,共5页
Transport of an underdamped Brownian particle in a one-dimensional asymmetric deformable potential is investigated in the presence of both an ac force and a static force,respectively.From numerical simulations,we obta... Transport of an underdamped Brownian particle in a one-dimensional asymmetric deformable potential is investigated in the presence of both an ac force and a static force,respectively.From numerical simulations,we obtain the current average velocity.The current reversals and the absolute negative mobility are presented.The increasing of the deformation of the potential can cause the absolute negative mobility to be suppressed and even disappear.When the static force is small,the increase of the potential deformation suppresses the absolute negative mobility.When the force is large,the absolute negative mobility disappears.In particular,when the potential deformation is equal to0.015,the two current reversals present with the increasing of the force.Remarkably,when the potential deformation is small,there are three current reversals with the increasing of the friction coefficient and the average velocity presents a oscillation behavior. 展开更多
关键词 particle transport asymmetric deformable potential absolute negative mobility current reversals
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