Pub Date : 2023-12-20DOI: 10.1088/1674-1056/ad1749
Ying Yang, Jiliang Jing
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 parameter $theta$, and $F_{theta}$ is the maximum for $theta=0$ or $theta=pi$, $F_{phi}$ is the maximum for $theta=pi/2$. We also obtain that the maximum value of QFI for state parameters varies for different spacetime dimensions with the same evolution time.
{"title":"Parameter estimation in $n$-dimensional massless scalar field","authors":"Ying Yang, Jiliang Jing","doi":"10.1088/1674-1056/ad1749","DOIUrl":"https://doi.org/10.1088/1674-1056/ad1749","url":null,"abstract":"\u0000 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 parameter $theta$, and $F_{theta}$ is the maximum for $theta=0$ or $theta=pi$, $F_{phi}$ is the maximum for $theta=pi/2$. We also obtain that the maximum value of QFI for state parameters varies for different spacetime dimensions with the same evolution time.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"17 11","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138956174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Raman lasers are essential in atomic physics, and the development of portable devices has posed requirements for time-division multiplexing of Raman lasers. We demonstrate an innovative gigahertz frequency hopping approach of the slave Raman laser within an optical phase-locked loop (OPLL), which finds practical application in an atomic gravimeter, where the OPLL frequently switches between near-resonance lasers and significantly detuned Raman lasers. The method merges the advantages of rapid and extensive frequency hopping with the OPLL’s inherent low phase noise, and exhibits a versatile range of applications in compact laser systems, promising advancements in portable instruments.
{"title":"Gigahertz frequency hopping in an optical phase-locked loop for Raman lasers","authors":"Dekai Mao, Hongmian Shui, Guoling Yin, Peng Peng, Chunwei Wang, Xiaoji Zhou","doi":"10.1088/1674-1056/ad174b","DOIUrl":"https://doi.org/10.1088/1674-1056/ad174b","url":null,"abstract":"\u0000 Raman lasers are essential in atomic physics, and the development of portable devices has posed requirements for time-division multiplexing of Raman lasers. We demonstrate an innovative gigahertz frequency hopping approach of the slave Raman laser within an optical phase-locked loop (OPLL), which finds practical application in an atomic gravimeter, where the OPLL frequently switches between near-resonance lasers and significantly detuned Raman lasers. The method merges the advantages of rapid and extensive frequency hopping with the OPLL’s inherent low phase noise, and exhibits a versatile range of applications in compact laser systems, promising advancements in portable instruments.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"3 25","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138956492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-20DOI: 10.1088/1674-1056/ad1748
Tao Li, Jing Zhou, Qi Sun, Zhi-Xiang Jin, Deng-Feng Liang, Ting Luo
Monogamy and polygamy relations are essential properties of quantum entanglement, which characterize the distributions of entanglement in multipartite systems. In this paper, we establish the general monogamy relations for $gamma$th $(0leqgamma leqalpha, alphageq 1)$ power of quantum entanglement based on unified-$(q,s)$ entanglement and polygamy relations for $delta$th $(deltageq beta, 0leqbetaleq1)$ power of entanglement of assistance based on unified-$(q,s)$ entanglement of assistance, which provides a complement to the previous research in terms of different parameter regions of $gamma$ and $delta$. These results are then applied to specific quantum correlations, e.g. entanglement of formation, Renyi-$q$ entanglement of assistance and Tsallis-$q$ entanglement of assistance to get the corresponding monogamy and polygamy inequalities. Moreover, typical examples are presented for illustration.
{"title":"Complementary monogamy and polygamy properties among multipartite systems","authors":"Tao Li, Jing Zhou, Qi Sun, Zhi-Xiang Jin, Deng-Feng Liang, Ting Luo","doi":"10.1088/1674-1056/ad1748","DOIUrl":"https://doi.org/10.1088/1674-1056/ad1748","url":null,"abstract":"\u0000 Monogamy and polygamy relations are essential properties of quantum entanglement, which characterize the distributions of entanglement in multipartite systems. In this paper, we establish the general monogamy relations for $gamma$th $(0leqgamma leqalpha, alphageq 1)$ power of quantum entanglement based on unified-$(q,s)$ entanglement and polygamy relations for $delta$th $(deltageq beta, 0leqbetaleq1)$ power of entanglement of assistance based on unified-$(q,s)$ entanglement of assistance, which provides a complement to the previous research in terms of different parameter regions of $gamma$ and $delta$. These results are then applied to specific quantum correlations, e.g. entanglement of formation, Renyi-$q$ entanglement of assistance and Tsallis-$q$ entanglement of assistance to get the corresponding monogamy and polygamy inequalities. Moreover, typical examples are presented for illustration.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"36 18","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138956519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-20DOI: 10.1088/1674-1056/ad1747
Xing-Yu Zhu, Le-Tian Zhu, Tao Tu, Chuan-Feng Li
Spin qubits and superconducting qubits are promising candidates for realizing solid-state quantum information processors. Designing a hybrid architecture that combines the advantages of different qubits on the same chip is a highly desirable but challenging goal. Here we propose a hybrid architecture that utilizes a high-impedance SQUID array resonator as a quantum bus, thereby coherently coupling different solid-state qubits. We employ a resonant exchange spin qubit hosted in a triple quantum dot and a superconducting transmon qubit. Since this hybrid system is highly tunable, it can operate in a dispersive regime, where the interaction between the different qubits is mediated by virtual photons. By utilizing such interactions, entangling gate operations between different qubits can be realized in a short time of 30 ns with a fidelity of up to 96.5% under realistic parameter conditions. Further utilizing this interaction, remote entangled state between different qubits can be prepared and is robust to perturbations of various parameters. These results pave the way for exploring efficient fault-tolerant quantum computation on hybrid quantum architecture platforms.
{"title":"Remote entangling gate between a quantum dot spin and a transmon qubit mediated by microwave photons","authors":"Xing-Yu Zhu, Le-Tian Zhu, Tao Tu, Chuan-Feng Li","doi":"10.1088/1674-1056/ad1747","DOIUrl":"https://doi.org/10.1088/1674-1056/ad1747","url":null,"abstract":"\u0000 Spin qubits and superconducting qubits are promising candidates for realizing solid-state quantum information processors. Designing a hybrid architecture that combines the advantages of different qubits on the same chip is a highly desirable but challenging goal. Here we propose a hybrid architecture that utilizes a high-impedance SQUID array resonator as a quantum bus, thereby coherently coupling different solid-state qubits. We employ a resonant exchange spin qubit hosted in a triple quantum dot and a superconducting transmon qubit. Since this hybrid system is highly tunable, it can operate in a dispersive regime, where the interaction between the different qubits is mediated by virtual photons. By utilizing such interactions, entangling gate operations between different qubits can be realized in a short time of 30 ns with a fidelity of up to 96.5% under realistic parameter conditions. Further utilizing this interaction, remote entangled state between different qubits can be prepared and is robust to perturbations of various parameters. These results pave the way for exploring efficient fault-tolerant quantum computation on hybrid quantum architecture platforms.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"116 49","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138958505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-19DOI: 10.1088/1674-1056/ad16d5
Haipeng Zhao, Yin Liu, Shengguo Yang, Chenfang Lin, Mingxing Chen, Kai Braun, Xinyi Luo, Siyu Li, Anlian Pan, Xiao Wang
Transition metal ditellurides (TMTDs) have versatile physical properties, including non-trivial topology, Weyl semimetal states and unique spin texture. Controlled growth of high-quality and large-scale monolayer TMTDs with preferred crystal phases is crucial for their applications. Here, we demonstrate the epitaxial growth of 1T'-MoTe2 on Au (111) and graphitized silicon carbide (Gr/SiC) by molecular beam epitaxy (MBE). We investigated the morphology of the grown 1T'-MoTe2 at the atomic level by scanning tunnelling microscopy (STM) and revealed the corresponding microscopic growth mechanism. We found that the unique ordered Te structures preferentially deposited on Au (111) regulated the growth of monolayer single crystal 1T'-MoTe2, while the Mo nucleation sites deposited on Gr/SiC substrate firstly instead of Te structures impeded the ordered growth of monolayer MoTe2. We confirm that the size of single crystal 1T'-MoTe2 grown on Au (111) is nearly two orders of magnitude larger than that on Gr/SiC. By scanning tunnelling spectroscopy (STS), We observe that the STS spectrum of the monolayer 1T'-MoTe2 nano-island at the edge is different from that at the interior, which exhibits enhanced conductivity.
过渡金属二碲化物（TMTDs）具有多种物理特性，包括非三维拓扑结构、韦尔半金属态和独特的自旋纹理。控制高质量、大规模、具有优选晶相的单层 TMTDs 的生长对其应用至关重要。在这里，我们展示了通过分子束外延（MBE）技术在金（111）和石墨化碳化硅（Gr/SiC）上外延生长 1T'-MoTe2 的过程。我们利用扫描隧道显微镜（STM）在原子水平上研究了生长出的 1T'-MoTe2 的形貌，并揭示了相应的微观生长机制。我们发现，优先沉积在金（111）上的独特有序 Te 结构调节了单层单晶 1T'-MoTe2 的生长，而首先沉积在 Gr/SiC 衬底上的 Mo 成核点而不是 Te 结构阻碍了单层 MoTe2 的有序生长。我们证实，生长在金（111）上的单晶 1T'-MoTe2 的尺寸比生长在 Gr/SiC 上的单晶 1T'-MoTe2 大近两个数量级。通过扫描隧穿光谱（STS），我们观察到单层 1T'-MoTe2 纳米岛边缘的 STS 光谱与内部不同，其导电性增强。
{"title":"Microscopic growth mechanism and edge states of monolayer 1T'-MoTe2","authors":"Haipeng Zhao, Yin Liu, Shengguo Yang, Chenfang Lin, Mingxing Chen, Kai Braun, Xinyi Luo, Siyu Li, Anlian Pan, Xiao Wang","doi":"10.1088/1674-1056/ad16d5","DOIUrl":"https://doi.org/10.1088/1674-1056/ad16d5","url":null,"abstract":"\u0000 Transition metal ditellurides (TMTDs) have versatile physical properties, including non-trivial topology, Weyl semimetal states and unique spin texture. Controlled growth of high-quality and large-scale monolayer TMTDs with preferred crystal phases is crucial for their applications. Here, we demonstrate the epitaxial growth of 1T'-MoTe2 on Au (111) and graphitized silicon carbide (Gr/SiC) by molecular beam epitaxy (MBE). We investigated the morphology of the grown 1T'-MoTe2 at the atomic level by scanning tunnelling microscopy (STM) and revealed the corresponding microscopic growth mechanism. We found that the unique ordered Te structures preferentially deposited on Au (111) regulated the growth of monolayer single crystal 1T'-MoTe2, while the Mo nucleation sites deposited on Gr/SiC substrate firstly instead of Te structures impeded the ordered growth of monolayer MoTe2. We confirm that the size of single crystal 1T'-MoTe2 grown on Au (111) is nearly two orders of magnitude larger than that on Gr/SiC. By scanning tunnelling spectroscopy (STS), We observe that the STS spectrum of the monolayer 1T'-MoTe2 nano-island at the edge is different from that at the interior, which exhibits enhanced conductivity.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"113 41","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138959685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-19DOI: 10.1088/1674-1056/ad16d4
Min Wang, Qiuyue Nie, Tao Huang, Xiaogang Wang, Yanjie Zhang
The HIT-PSI is a linear plasma device built for physically simulating the high heat flux environment of future reactor divertors to test/develop advanced target plate materials. In this study, the geometry modified SOLPS-ITER program is employed to examine the effects of the magnetic field strength and neutral pressure in the device on the heat flux experienced by the target plate of the HIT-PSI device. The findings of the numerical simulation indicate a positive correlation between the magnetic field strength and the heat flux density. Conversely, there is a negative correlation observed between the heat flux density and the neutral pressure. When the magnetic field strength at the axis exceeds 1 tesla and the neutral pressure falls below 10 Pa, the HIT-PSI has the capability to attain a heat flux of 10MV·m-2 at the target plate. The simulation results offer a valuable point of reference for subsequent experiments at HIT-PSI.
{"title":"Numerical Studies for plasmas of a linear plasma device HIT-PSI with geometry modified SOLPS-ITER.","authors":"Min Wang, Qiuyue Nie, Tao Huang, Xiaogang Wang, Yanjie Zhang","doi":"10.1088/1674-1056/ad16d4","DOIUrl":"https://doi.org/10.1088/1674-1056/ad16d4","url":null,"abstract":"\u0000 The HIT-PSI is a linear plasma device built for physically simulating the high heat flux environment of future reactor divertors to test/develop advanced target plate materials. In this study, the geometry modified SOLPS-ITER program is employed to examine the effects of the magnetic field strength and neutral pressure in the device on the heat flux experienced by the target plate of the HIT-PSI device. The findings of the numerical simulation indicate a positive correlation between the magnetic field strength and the heat flux density. Conversely, there is a negative correlation observed between the heat flux density and the neutral pressure. When the magnetic field strength at the axis exceeds 1 tesla and the neutral pressure falls below 10 Pa, the HIT-PSI has the capability to attain a heat flux of 10MV·m-2 at the target plate. The simulation results offer a valuable point of reference for subsequent experiments at HIT-PSI.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":" 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138960818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Systemically angular and planar transport investigations are performed in layered antiferromagnetic (AF) V5S8. In this AF system, obvious anomalous Hall effect (AHE) is observed with a large Hall angle of 0.1 compared to that in ferromagnetic (FM) system. It can persist to the temperatures above AF transition and exhibit strong angular field dependence. The phase diagram reveals the various magnetic states with rotating the applied field. By analyzing the anisotropic transport behavior, magnon contributions are revealed and exhibit obvious angular dependence with a spin-flop vanishing line. The observed prominent planar Hall effect and anistrpoic magnetoresisitivity exhibit two-fold systematical angular dependent oscillations. These behavior are attributed to the scattering from spin-orbital coupling instead of nontrivial topological origin. Our results reveal anisotropic interactions of magnetism and electron for V5S8 suggesting potential opportunities for the AF spintronic sensor and devices.
在层状反铁磁（AF）V5S8 中进行了系统角度和平面输运研究。与铁磁（FM）系统相比，在这种反铁磁系统中，当霍尔角达到 0.1 时，会出现明显的反常霍尔效应（AHE）。它可以持续到 AF 转变以上的温度，并表现出很强的角场依赖性。相图显示了旋转外加磁场时的各种磁态。通过分析各向异性的传输行为，磁子贡献被揭示出来，并表现出明显的角度依赖性和自旋翻转消失线。观察到的突出平面霍尔效应和各向异性磁致伸缩表现出两重系统性的角度相关振荡。这些行为归因于自旋轨道耦合的散射，而不是非对称拓扑起源。我们的研究结果揭示了 V5S8 的磁性和电子的各向异性相互作用，为 AF 自旋电子传感器和器件提供了潜在的机遇。
{"title":"Angular and Planar transport properties for antiferromagnetic V5S8","authors":"Xiao-Kai Wu, Bin Wang, De-Tong Wu, Bo-Wen Chen, Meng-Juan Mi, Yi-Lin Wang, Bing Shen","doi":"10.1088/1674-1056/ad15f9","DOIUrl":"https://doi.org/10.1088/1674-1056/ad15f9","url":null,"abstract":"\u0000 Systemically angular and planar transport investigations are performed in layered antiferromagnetic (AF) V5S8. In this AF system, obvious anomalous Hall effect (AHE) is observed with a large Hall angle of 0.1 compared to that in ferromagnetic (FM) system. It can persist to the temperatures above AF transition and exhibit strong angular field dependence. The phase diagram reveals the various magnetic states with rotating the applied field. By analyzing the anisotropic transport behavior, magnon contributions are revealed and exhibit obvious angular dependence with a spin-flop vanishing line. The observed prominent planar Hall effect and anistrpoic magnetoresisitivity exhibit two-fold systematical angular dependent oscillations. These behavior are attributed to the scattering from spin-orbital coupling instead of nontrivial topological origin. Our results reveal anisotropic interactions of magnetism and electron for V5S8 suggesting potential opportunities for the AF spintronic sensor and devices.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"17 68","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138999113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Non-magnetic semiconductor materials and their devices have attracted wide attention since they are usually prone to exhibit large positive magnetoresistance (MR) effect in a low static magnetic field environment at room temperature. However, how to obtain a large room-temperature negative MR effect in them remains to be studied. In this paper, by designing an Au/n-Ge:Sb/Au device with metal electrodes located on identical side, we observe an obvious room-temperature negative MR effect in a specific 50 T pulsed high magnetic field direction environment, but not in a static low magnetic field environment. Through the analysis of the experimental measurement of the Hall effect results and bipolar transport theory, we propose that this unconventional negative MR effect is mainly related to the charge accumulation on the surface of the device under the modulation of the stronger Lorentz force provided by the pulsed high magnetic field. This theoretical analytical model is further confirmed by regulating the geometry size of the device. Our work sheds light on the development of novel magnetic sensing, magnetic logic and other devices based on non-magnetic semiconductors operating in pulsed high magnetic field environment.
由于非磁性半导体材料及其器件通常容易在室温低静态磁场环境下表现出较大的正磁阻（MR）效应，因此受到广泛关注。然而，如何在它们身上获得大的室温负磁阻效应仍有待研究。本文通过设计一个金属电极位于同一侧的金/锗：锑/金器件，在特定的 50 T 脉冲高磁场方向环境中观察到了明显的室温负磁阻效应，而在静态低磁场环境中却没有观察到。通过对霍尔效应实验测量结果和双极输运理论的分析，我们提出这种非常规的负磁共振效应主要与脉冲高磁场提供的较强洛伦兹力调制下器件表面的电荷积累有关。这一理论分析模型通过调节器件的几何尺寸得到了进一步证实。我们的研究成果为开发基于非磁性半导体、在脉冲高磁场环境中工作的新型磁性传感、磁性逻辑和其他器件提供了启示。
{"title":"Unconventional room-temperature negative magnetoresistance effect in Au/n-Ge:Sb/Au device","authors":"Xiong He, Fan-Li Yang, Hao-Yu Niu, Li-Feng Wang, Li-Zhi Yi, Yun-Li Xu, Min Liu, Li-Qing Pan, Zheng-Cai Xia","doi":"10.1088/1674-1056/ad15f8","DOIUrl":"https://doi.org/10.1088/1674-1056/ad15f8","url":null,"abstract":"\u0000 Non-magnetic semiconductor materials and their devices have attracted wide attention since they are usually prone to exhibit large positive magnetoresistance (MR) effect in a low static magnetic field environment at room temperature. However, how to obtain a large room-temperature negative MR effect in them remains to be studied. In this paper, by designing an Au/n-Ge:Sb/Au device with metal electrodes located on identical side, we observe an obvious room-temperature negative MR effect in a specific 50 T pulsed high magnetic field direction environment, but not in a static low magnetic field environment. Through the analysis of the experimental measurement of the Hall effect results and bipolar transport theory, we propose that this unconventional negative MR effect is mainly related to the charge accumulation on the surface of the device under the modulation of the stronger Lorentz force provided by the pulsed high magnetic field. This theoretical analytical model is further confirmed by regulating the geometry size of the device. Our work sheds light on the development of novel magnetic sensing, magnetic logic and other devices based on non-magnetic semiconductors operating in pulsed high magnetic field environment.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"341 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138996549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-13DOI: 10.1088/1674-1056/ad1501
Yi Li, Yinong Liu, Shiqian Hu
The drive for efficient thermal management has intensified with the miniaturization of electronic devices. This study explores the modulation of phonon transport within graphene by introducing silicon nanoparticles influenced by van der Waals forces. Our approach involves the application of non-equilibrium molecular dynamics to assess thermal conductivity while varying the interaction strength, leading to a noteworthy reduction in thermal conductivity. Furthermore, we observe a distinct attenuation in length-dependent behavior within the graphene-nanoparticles system. Our exploration combines wave packet simulations with phonon transmission calculations, aligning with a comprehensive analysis of the phonon transport regime to unveil the underlying physical mechanisms at play. Lastly, we conduct transient molecular dynamics simulations to investigate interfacial thermal conductance between the nanoparticles and the graphene, revealing an enhanced TBC. This research not only contributes to our understanding of phonon transport but also opens a new degree of freedom for utilizing van der Waals nanoparticle-induced resonance, offering promising avenues for the modulation of thermal properties in advanced materials and enhancing their performance in various technological applications.
{"title":"Phonon Resonance Modulation in Weak van der Waals Heterostructures: Controlling Thermal Transport in Graphene-Silicon Nanoparticle Systems","authors":"Yi Li, Yinong Liu, Shiqian Hu","doi":"10.1088/1674-1056/ad1501","DOIUrl":"https://doi.org/10.1088/1674-1056/ad1501","url":null,"abstract":"\u0000 The drive for efficient thermal management has intensified with the miniaturization of electronic devices. This study explores the modulation of phonon transport within graphene by introducing silicon nanoparticles influenced by van der Waals forces. Our approach involves the application of non-equilibrium molecular dynamics to assess thermal conductivity while varying the interaction strength, leading to a noteworthy reduction in thermal conductivity. Furthermore, we observe a distinct attenuation in length-dependent behavior within the graphene-nanoparticles system. Our exploration combines wave packet simulations with phonon transmission calculations, aligning with a comprehensive analysis of the phonon transport regime to unveil the underlying physical mechanisms at play. Lastly, we conduct transient molecular dynamics simulations to investigate interfacial thermal conductance between the nanoparticles and the graphene, revealing an enhanced TBC. This research not only contributes to our understanding of phonon transport but also opens a new degree of freedom for utilizing van der Waals nanoparticle-induced resonance, offering promising avenues for the modulation of thermal properties in advanced materials and enhancing their performance in various technological applications.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"6 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139005404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-13DOI: 10.1088/1674-1056/ad1500
Zengqiang Cao, Chaoyu Wang, Honggang Zhang, Bo You, Yuxiang Ni
Through equilibrium and non-equilibrium molecular dynamics simulations, we have demonstrated the inhibitory effect of interface composition graded on thermal transport behavior in lateral heterostructures. Specifically, we investigated the influence of composition gradient length and heterogeneous particles at the silicene/germanene heterostructure interface on heat conduction. Our results indicate that composition graded at the interface diminishes the thermal conductivity of the heterostructure, with a further reduction observed as the length increases, while the effect of the heterogeneous particles can be considered negligible. To unveil the influence of composition graded at the interface on thermal transport, we conducted phonon analysis and identified the presence of phonon localization within the interface composition graded region. Through these analyses, we have determined that the decrease in thermal conductivity is correlated with phonon localization within the heterostructure, where a stronger degree of phonon localization signifies poorer thermal conductivity in the material. Our research findings not only contribute to understanding the impact of interface gradient-induced phonon localization on thermal transport but also offer insights into the modulation of thermal conductivity in heterostructures.
{"title":"Thermal transport in composition graded silicene/germanene heterostructures","authors":"Zengqiang Cao, Chaoyu Wang, Honggang Zhang, Bo You, Yuxiang Ni","doi":"10.1088/1674-1056/ad1500","DOIUrl":"https://doi.org/10.1088/1674-1056/ad1500","url":null,"abstract":"\u0000 Through equilibrium and non-equilibrium molecular dynamics simulations, we have demonstrated the inhibitory effect of interface composition graded on thermal transport behavior in lateral heterostructures. Specifically, we investigated the influence of composition gradient length and heterogeneous particles at the silicene/germanene heterostructure interface on heat conduction. Our results indicate that composition graded at the interface diminishes the thermal conductivity of the heterostructure, with a further reduction observed as the length increases, while the effect of the heterogeneous particles can be considered negligible. To unveil the influence of composition graded at the interface on thermal transport, we conducted phonon analysis and identified the presence of phonon localization within the interface composition graded region. Through these analyses, we have determined that the decrease in thermal conductivity is correlated with phonon localization within the heterostructure, where a stronger degree of phonon localization signifies poorer thermal conductivity in the material. Our research findings not only contribute to understanding the impact of interface gradient-induced phonon localization on thermal transport but also offer insights into the modulation of thermal conductivity in heterostructures.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"93 S86","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138976809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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