检索结果-南通市图书馆

quantum phase transition of the Jaynes-Cummings model

Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 1-9页

作者： Cheng Liu Jin-Feng Huang key laboratory of Low-Dimensional quantum structures and quantum control of Ministry of Education Key Laboratory for Matter Microstructure and Function of Hunan ProvinceDepartment of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsInstitute of Interdisciplinary StudiesHunan Normal UniversityChangsha 410081China

Herein,we propose an experimentally feasible scheme to show the quantum phase transition of the Jaynes-Cummings(JC)model by modulating the transition frequency of a two-level system in a quantum Rabi model with strong coupling.By tuning the modulation frequency and amplitude,the ratio of the effective coupling strength of the rotating terms to the effective cavity(atomic transition)frequency can enter the deep-strong coupling regime,while the counter-rotating terms can be neglected.Thus,a deep-strong JC model is obtained.The ratio of the coupling strength to resonance frequencies in the deep-strong JC model is two orders of magnitude larger than the corresponding ratio in the original quantum Rabi model.Our scheme can be employed in atom-cavity resonance and off-resonance cases,and it is valid over a broad range.The nonzero average cavity photons of the ground state indicate the emergence of a quantum phase transition.Further,we demonstrate the dependence of the phase diagram on the atom-cavity detuning and modulation parameters.All the parameters used in our scheme are within the reach of current experimental technology.Our scheme provides a new mechanism for investigating the critical phenomena of finite-sized systems without requiring classical field limits,thereby opening a door for studying fundamental quantum phenomena occurring in the ultrastrong and even deep-strong coupling regimes.

关键词： Jaynes-Cummings model quantum phase transition frequency modulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Energy flux and waveforms by coalescing spinless binary system in effective one-body theory

引用

Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 58-68页

作者： Sheng Long Weike Deng Jiliang Jing Department of Physics Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China

We present a study on the energy radiation rate and waveforms of the gravitational wave generated by coalescing spinless binary systems up to the third post-Minkowskian approximation in the effective one-body theory.To derive an analytical expansion of the null tetrad components of the gravitational perturbed Weyl tensorΨ4in the effective spacetime,we utilize the method proposed by Sasaki et al.During this investigation,we discover more general integral formulas that provide a theoretical framework for computing the results in any order.Subsequently,we successfully compute the energy radiation rate and waveforms of the gravitational wave,which include the results of the Schwarzschild case and the correction terms resulting from the dimensionless parameters a2and a3in the effective metric.

关键词： post-Minkowskian approximation effective one-body theory gravitational waveform template

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chiral bound states in a staggered array of coupled resonators

引用

Chinese Physics B 2024年第2期33卷 124-130页

作者：金伍林李静卢竞龚志瑞周兰 Synergetic Innovation center for quantum Effects and Applications Key Laboratory for Matter Microstructure and Function of Hunan ProvinceKey Laboratory of Low-Dimensional Quantum Structures and Quantum Control of the Ministry of EducationSynergetic Innovation Center for Quantum Effects and ApplicationsInstitute of Interdisciplinary StudiesXiangjiang-Laboratory and Department of PhysicsHunan Normal UniversityChangsha 410081China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China

We study the chiral bound states in a coupled-resonator array with staggered hopping strengths,which interacts with a two-level small atom through a single coupling point or two adjacent ones.In addition to the two typical bound states found above and below the energy bands,this system presents an extraordinary chiral bound state located within the energy gap.We use the chirality to quantify the breaking of the mirror symmetry.We find that the chirality value undergoes continuous changes by tuning the coupling strengths.The preferred direction of the chirality is controlled not only by the competition between the intracell and the intercell hoppings in the coupled-resonator array,but also by the coherence between the two coupling points.In the case with one coupling point,the chirality values varies monotonously with difference between the intracell hopping and the intercell hoppings.While in the case with two coupling points,due to the coherence between the two coupling points the perfect chiral states can be obtained.

关键词： bound states two-level small atom coupled-resonator array chirality

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Parameter estimation in n-dimensional massless scalar field

引用

Chinese Physics B 2024年第3期33卷 231-237页

作者：杨颖荆继良 Hunan Provincial key laboratory of Intelligent Sensors and Advanced Sensor Materials School of Physics and ElectronicsHunan University of Science and TechnologyXiangtan 411201China Department of Physics Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Educationand Synergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081Chin

quantum Fisher information(QFI)associated with local metrology has been used to parameter estimation in open quantum systems.In this work,we calculated the QFI for a moving Unruh-DeWitt detector coupled with massless scalar fields in n-dimensional spacetime,and analyzed the behavior of QFI with various parameters,such as the dimension of spacetime,evolution time,and Unruh temperature.We discovered that the QFI of state parameter decreases monotonically from 1 to 0 over time.Additionally,we noted that the QFI for small evolution times is several orders of magnitude higher than the QFI for long evolution times.We also found that the value of QFI decreases at first and then stabilizes as the Unruh temperature increases.It was observed that the QFI depends on initial state parameterθ,and Fθis the maximum forθ=0 orθ=π,Fφis the maximum forθ=π/2.We also obtain that the maximum value of QFI for state parameters varies for different spacetime dimensions with the same evolution time.

关键词： quantum Fisher information parameter estimation open quantum systems

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Kerr black hole shadows cast by extraordinary light rays with Weyl corrections

引用

Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 18-26页

作者： Songbai Chen Jiliang Jing Department of Physics Institute of Interdisciplinary StudiesKey Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China

We investigate the equation of motion for photons with Weyl corrections in a Kerr black hole spacetime in a small coupling case.Our results show that Weyl corrections yield phenomena of birefringence.The light rays propagating in the spacetime are separated into the ordinary rays and the extraordinary rays,and the propagation of the latter depends on the corrections.We probe the effects of Weyl corrections on the Kerr black hole shadows casted by the extraordinary rays and find that such corrections result in a weak stretching or squeezing in the vertical direction for the black hole shadows.Finally,we also study the change of the length of the Near-Horizon Extremal Kerr line(NHEK line)with Weyl corrections.These features could help us to understand the electrodynamics with Weyl corrections from black hole shadows.

关键词： correction light stretching

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Bimodal growth of Fe islands on graphene

引用

Chinese Physics B 2024年第6期33卷 553-557页

作者：顾翊晟俞俏滟刘荡孙蓟策席瑞骏陈星森薛莎莎章毅杜宪宁旭辉杨浩管丹丹刘晓雪刘亮李耀义王世勇刘灿华郑浩贾金锋 key laboratory of artificial structures and quantum control TD Lee InstituteShenyang National Laboratory for Materials ScienceSchool of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Department of Physics Southern University of Science and TechnologyShenzhen 518055China quantum Science center of Guangdong-Hong Kong-Macao Greater Bay Area(Guangdong) Shenzhen 518045China

Magnetic metals deposited on graphene hold the key to applications in spintronics. Here, we present the results of Fe islands grown on graphene/Si C(0001) by molecular beam epitaxy, which are investigated by scanning tunneling microscopy. The two types of islands distinguished by flat or round tops are revealed, indicating bimodal growth of Fe. The atomic structures on the top surfaces of flat islands are also clearly resolved. Our results may improve the understanding of the mechanisms of metals deposited on graphene and pave the way for future spintronic applications of Fe/graphene systems.

关键词： graphene magnetism molecular beam epitaxy scanning tunneling microscopy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Lorentz violation induces isospectrality breaking in Einstein-bumblebee gravity theory

引用

Science China(Physics,Mechanics & Astronomy) 2024年

作者： Wentao Liu Xiongjun Fang Jiliang Jing Jieci Wang Department of Physics Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and Applications Hunan Normal University

In this study, we investigate the quasinormal modes(QNMs) of a Lorentz-violating spacetime, factoring in a cosmological constant, within the framework of Einstein-bumblebee gravity. Our findings reveal that the interaction of spacetime with an anisotropic bumblebee field imparts distinct contributions to the axial and polar sectors of the vector perturbations. This subsequently breaks the isospectrality typically observed in vector modes. Numerical evidence strongly indicates isospectral breaking in the vector modes of Einstein-bumblebee black holes: a pronounced breakage in the real part of the frequencies, while the imaginary component seems less affected. This isospectral breaking indicates the existence of two different waveforms in the Ringdown phase of the black hole, which provides a potential signal of quantum gravity observable in current experiments.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Gravitational wave fluxes on generic orbits in near-extreme Kerr spacetime:Higher spin and large eccentricity

引用

Science China(Physics,Mechanics & Astronomy) 2024年

作者： Changkai Chen Jiliang Jing Department of Physics Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and Applications Hunan Normal University

To accurately obtain the waveform template of gravitational waves, substantial computational resources and extremely high precision are often required. In a previous study, we employed the confluent Heun function to obtain an exact solution to the Teukolsky equation. This approach allowed us to efficiently and accurately calculate the gravitational wave flux for a particle in circular orbits around a Schwarzschild black hole. Building on this method, we now extend its application to calculate the asymptotic gravitational wave fluxes from a particle in generic orbits around a near-extreme Kerr black hole. Our extended method proves particularly effective in handling computational challenges associated with large eccentricities(e = 0.9), higher spins(a = 0.999), higher harmonic modes, and strong-field regions. The results we obtained significantly outperform those derived from the numerical integration method based on the Mano-Suzuki-Takasugi method.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Fermi level tuning in SnPbTe/Pb heterostructure via changing interface roughness

引用

Science China(Physics,Mechanics & Astronomy) 2024年

作者： Tengteng Liu Zhaoxia Yi Bangjin Xie Weiyan Zheng Dandan Guan Shiyong Wang Hao Zheng Canhua Liu Hao Yang Yaoyi Li Jinfeng Jia key laboratory of artificial structures and quantum control (Ministry of Education) Tsung-Dao Lee InstituteSchool of Physics and AstronomyShanghai Jiao Tong University Shanghai Research center for quantum Sciences Hefei National laboratory

Superconducting SnTe-type topological crystalline insulators （TCIs） are predicted to host multiple Majorana zero modes（MZMs） which can coexist in a single vortex. Fermi level （FL） close to the Dirac points of topological surface states is helpful for detecting MZMs. However, the TCI SnTe is a heavily p-type semiconductor which is very difficult to modify to n-type via doping or alloying. In this work, we fabricate the atomically flat Sn1-xPbxTe/Pb heterostructure by molecular beam epitaxy, and make the p-type Sn1-xPbxTe become n-type through changing the interface roughness. Using scanning tunnelling microscope, we find the Dirac points of Sn1-xPbxTe/Pb heterostructure are always above the FL due to the Fermi level pinning （FLP） induced by topological surface states at atomically flat interface. After increasing the interface roughness, the FLP effect is suppressed and then the Dirac points of p-type Sn1-xPbxTe can be tuned very close to or even below the FL. Our work provides a new method for tuning the FL of SnTe-type TCI which has potential application in novel topological superconductor device.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Merger estimates for a disformal Kerr black hole in quadratic degenerate higher-order scalar-tensor theories

引用

Chinese Physics C 2024年第5期48卷 284-292页

作者：蒋洪鑫杜欣怡潘启沅陈松柏荆继良 key laboratory of Low Dimensional quantum structures and quantum control of Ministry of Education Synergetic Innovation Center for Quantum Effects and Applicationsand Department of PhysicsHunan Normal UniversityChangsha 410081China Institute of Interdisciplinary Studies Hunan Normal UniversityChangsha 410081China center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China

We investigate the main features of a disformal Kerr black hole merger in quadratic degenerate higher-order scalar-tensor theories.In the ringdown stage of the black hole merger,for the prograde orbit,the real part of the quasinormal modes decreases with an increase in the disformal parameter,and the imaginary part also decreases,except in the Kerr case for a large spin parameter.However,for the retrograde orbit,the real part increases with an increase in the disformal parameter,and the imaginary part always decreases with it.For the approximate final spin,regardless of an equal spin,unequal spin,or generic spin configuration merger,the final black hole spin always increases with an increase in the disformal parameter.Our results show that the disformal parameter in the disformal Kerr solution and the MOG parameter in the Kerr-MOG case have obviously different effects on the black hole merger,which suggests the differences between these two spacetime structures.

关键词： black hole merger quasinormal modes final black hole spin disformal Kerr black hole quadratic degenerate higher-order scalar-tensor(DHOST)theory

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

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

在线全文

在线全文

在线全文

在线全文

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

在线全文

在线全文

在线全文

在线全文

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：