Pub Date : 2024-10-16DOI: 10.1016/j.physleta.2024.129983
W. Chen , L.M. Yu , P.W. Shi , Y.M. Hou , Z.B. Shi , J. Bao , Z. Qiu , X.Q. Ji , X.X. He , Y.G. Li , M. Jiang , X. Yu , D.L. Yu , Z.C. Yang , Yi. Liu , H.T. Chen , X.L. Zhu , X. Jiang , Y.P. Zhang , Z.X. Wang , X.R. Duan
High-performance plasmas had been obtained with hybrid scenarios on HL-2A in past several years, and the quality factor is around 0.3-0.4. In these high- H-mode plasmas with and Chen et al. (2022) [24], there are multiple energetic-ion driven instabilities, such as toroidal Alfvén eigenmode (TAE) and beta-induced Alfvén eigenmode (BAE), and there are complex magnetohydrodynamic (MHD) dynamics, e.g. nonlinear mode-mode and mode-particle interactions. The TAE amplitude increases explosively, and the frequency is fast chirping in the range of kHz. The TAE toroidal mode-number is , and they localize in outer plasma region. The BAE amplitude also increases explosively, and the BAE frequency is fast chirping in the range of kHz. The toroidal mode-number of dominant BAEs is , and these modes localize at q=2 rational surface where there is a large radius internal transport barrier (ITB). Generally, the energetic-ion fraction is low in outer plasma region. It indicates that thermal ions at large radius ITB location possibly provide additional drive and destabilize the BAE in company with energetic-ions. These TAEs/BAEs occur regularly in high- region and before large type-I ELM burst. To further illuminate the characteristics of these Alfvénic modes, the 2D and radial mode structures had been calculated by using a well-benchmarked general Alfvénic mode eigenvalue code (MAS). The experimental results suggest that these Alfvénic modes may have important effects on the pedestal transport and ELM-onset.
{"title":"Nonlinear dynamics and effects of fast-ion driven instabilities in HL-2A NBI heating high-βN H-mode plasmas","authors":"W. Chen , L.M. Yu , P.W. Shi , Y.M. Hou , Z.B. Shi , J. Bao , Z. Qiu , X.Q. Ji , X.X. He , Y.G. Li , M. Jiang , X. Yu , D.L. Yu , Z.C. Yang , Yi. Liu , H.T. Chen , X.L. Zhu , X. Jiang , Y.P. Zhang , Z.X. Wang , X.R. Duan","doi":"10.1016/j.physleta.2024.129983","DOIUrl":"10.1016/j.physleta.2024.129983","url":null,"abstract":"<div><div>High-performance plasmas had been obtained with hybrid scenarios on HL-2A in past several years, and the quality factor <span><math><mi>G</mi><mo>=</mo><msub><mrow><mi>H</mi></mrow><mrow><mn>89</mn></mrow></msub><msub><mrow><mi>β</mi></mrow><mrow><mi>N</mi></mrow></msub><mo>/</mo><msubsup><mrow><mi>q</mi></mrow><mrow><mn>95</mn></mrow><mrow><mn>2</mn></mrow></msubsup></math></span> is around 0.3-0.4. In these high-<span><math><msub><mrow><mi>β</mi></mrow><mrow><mi>N</mi></mrow></msub></math></span> H-mode plasmas with <span><math><msub><mrow><mi>β</mi></mrow><mrow><mi>N</mi></mrow></msub><mo>></mo><mn>2.5</mn></math></span> and <span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>98</mn></mrow></msub><mo>></mo><mn>1.2</mn></math></span> Chen et al. (2022) <span><span>[24]</span></span>, there are multiple energetic-ion driven instabilities, such as toroidal Alfvén eigenmode (TAE) and beta-induced Alfvén eigenmode (BAE), and there are complex magnetohydrodynamic (MHD) dynamics, e.g. nonlinear mode-mode and mode-particle interactions. The TAE amplitude increases explosively, and the frequency is fast chirping in the range of <span><math><mi>f</mi><mo>=</mo><mn>90</mn><mo>−</mo><mn>150</mn></math></span> kHz. The TAE toroidal mode-number is <span><math><mi>n</mi><mo>=</mo><mn>3</mn><mo>−</mo><mn>4</mn></math></span>, and they localize in outer plasma region. The BAE amplitude also increases explosively, and the BAE frequency is fast chirping in the range of <span><math><mi>f</mi><mo>=</mo><mn>50</mn><mo>−</mo><mn>90</mn></math></span> kHz. The toroidal mode-number of dominant BAEs is <span><math><mi>n</mi><mo>=</mo><mn>2</mn></math></span>, and these modes localize at q=2 rational surface where there is a large radius internal transport barrier (ITB). Generally, the energetic-ion fraction is low in outer plasma region. It indicates that thermal ions at large radius ITB location possibly provide additional drive and destabilize the BAE in company with energetic-ions. These TAEs/BAEs occur regularly in high-<span><math><msub><mrow><mi>β</mi></mrow><mrow><mi>N</mi></mrow></msub></math></span> region and before large type-I ELM burst. To further illuminate the characteristics of these Alfvénic modes, the 2D and radial mode structures had been calculated by using a well-benchmarked general Alfvénic mode eigenvalue code (MAS). The experimental results suggest that these Alfvénic modes may have important effects on the pedestal transport and ELM-onset.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"527 ","pages":"Article 129983"},"PeriodicalIF":2.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-16DOI: 10.1016/j.physleta.2024.129984
Ting Zhang , Laishui Lv , Dalal Bardou
Temporal link prediction has been extensively studied and widely applied in various applications, aiming to predict future network links based on the historical networks. However, most existing methods ignore the behavior of previous network updating information in temporal networks. To address these issues, we propose a novel link prediction model based on adversarial nonnegative matrix factorization, which fuses graph representation and adversarial learning to perform temporal link prediction. Specifically, we add a bounded adversary matrix to the input matrix to provide the robustness against real perturbations. Then, our model fully exploits the impact of snapshots by using communicability. Simultaneously, we utilize the cosine similarity to extract the node similarity and map it to low-dimensional latent representation to preserve the local structure. Additionally, we provide effective updating rules to learn the parameters of this model. Extensive experiments results on six real-world networks demonstrate that the proposed method outperforms several classical and the state-of-art matrix-based methods.
{"title":"Adversarial nonnegative matrix factorization for temporal link prediction","authors":"Ting Zhang , Laishui Lv , Dalal Bardou","doi":"10.1016/j.physleta.2024.129984","DOIUrl":"10.1016/j.physleta.2024.129984","url":null,"abstract":"<div><div>Temporal link prediction has been extensively studied and widely applied in various applications, aiming to predict future network links based on the historical networks. However, most existing methods ignore the behavior of previous network updating information in temporal networks. To address these issues, we propose a novel link prediction model based on adversarial nonnegative matrix factorization, which fuses graph representation and adversarial learning to perform temporal link prediction. Specifically, we add a bounded adversary matrix to the input matrix to provide the robustness against real perturbations. Then, our model fully exploits the impact of snapshots by using communicability. Simultaneously, we utilize the cosine similarity to extract the node similarity and map it to low-dimensional latent representation to preserve the local structure. Additionally, we provide effective updating rules to learn the parameters of this model. Extensive experiments results on six real-world networks demonstrate that the proposed method outperforms several classical and the state-of-art matrix-based methods.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"527 ","pages":"Article 129984"},"PeriodicalIF":2.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-16DOI: 10.1016/j.physleta.2024.129985
Yuwen Wang , Jiachen Li , Jianing Li , Wenjie Li , Chun Yang , Xiaoyang Liu , Wei Wang
Chronic HBV infection is a dynamic process of rapid viral replication and clearance, with large amounts of virus being produced and lost in the body daily. The patient's visit behaviour is closely related to viral load in the body, while the data-driven mathematical model still lacking. Therefore, we first include 28,912 patients to investigate the relationships between the visit behaviour and the HBV-DNA virus load. Then, we propose an HBV virus infection dynamics model that considers the patient's visit behaviour. The system is chaotic once the behaviour of patients during visits depends on the virus load. Our results may help us understand the process of viral transmission, and increasing the visit probability to the clinic can lead to stabilising HBV-DNA viral loads and further help healthcare professionals develop targeted clinical intervention strategies.
{"title":"Patient visit behaviour shapes the virus infection dynamics in hosts","authors":"Yuwen Wang , Jiachen Li , Jianing Li , Wenjie Li , Chun Yang , Xiaoyang Liu , Wei Wang","doi":"10.1016/j.physleta.2024.129985","DOIUrl":"10.1016/j.physleta.2024.129985","url":null,"abstract":"<div><div>Chronic HBV infection is a dynamic process of rapid viral replication and clearance, with large amounts of virus being produced and lost in the body daily. The patient's visit behaviour is closely related to viral load in the body, while the data-driven mathematical model still lacking. Therefore, we first include 28,912 patients to investigate the relationships between the visit behaviour and the HBV-DNA virus load. Then, we propose an HBV virus infection dynamics model that considers the patient's visit behaviour. The system is chaotic once the behaviour of patients during visits depends on the virus load. Our results may help us understand the process of viral transmission, and increasing the visit probability to the clinic can lead to stabilising HBV-DNA viral loads and further help healthcare professionals develop targeted clinical intervention strategies.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"527 ","pages":"Article 129985"},"PeriodicalIF":2.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-16DOI: 10.1016/j.physleta.2024.129986
G.T. Adamashvili
The generalized equation for the study of two-component nonlinear waves in different fields of physics is considered. In special cases, this equation is reduced to a set of the various well-known equations describing nonlinear solitary waves in the different areas of physics. Using the generalized perturbation reduction method the explicit analytical expressions for the shape and parameters of two-component nonlinear wave is presented. This nonlinear wave solution coincides with the vector 0π pulse of the self-induced transparency.
{"title":"Two-component nonlinear waves","authors":"G.T. Adamashvili","doi":"10.1016/j.physleta.2024.129986","DOIUrl":"10.1016/j.physleta.2024.129986","url":null,"abstract":"<div><div>The generalized equation for the study of two-component nonlinear waves in different fields of physics is considered. In special cases, this equation is reduced to a set of the various well-known equations describing nonlinear solitary waves in the different areas of physics. Using the generalized perturbation reduction method the explicit analytical expressions for the shape and parameters of two-component nonlinear wave is presented. This nonlinear wave solution coincides with the vector 0<em>π</em> pulse of the self-induced transparency.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"526 ","pages":"Article 129986"},"PeriodicalIF":2.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-15DOI: 10.1016/j.physleta.2024.129980
M. Ayala-Quitiaquez , J.P. Naranjo-Rendón , S. Ríos-Álvarez , Y.A. Suaza , J.H. Marín
The electronic and optical properties of an electron in realistic rectangle-shaped crater quantum rings under orthogonal electric and magnetic fields have been theoretically studied. The Schrödinger wave equation was solved using the finite element method within the effective mass approximation. A Stark effect with anomalous oscillatory behavior was observed for electric field strengths less than 10 kV/cm. The threading magnetic field leads to the formation of damped oscillations in the absorption coefficient peaks, which are closely related both to the Aharonov-Bohm oscillations and to a shift of the absorption peaks towards blue or red, depending on the dimensions and morphology of the central crater. Our model is sufficiently flexible such that several results appear as particular cases of the quantum ring with a rectangular central crater.
{"title":"Electro-optical properties of rectangle-shaped crater quantum rings under orthogonal electric and magnetic fields","authors":"M. Ayala-Quitiaquez , J.P. Naranjo-Rendón , S. Ríos-Álvarez , Y.A. Suaza , J.H. Marín","doi":"10.1016/j.physleta.2024.129980","DOIUrl":"10.1016/j.physleta.2024.129980","url":null,"abstract":"<div><div>The electronic and optical properties of an electron in realistic rectangle-shaped crater quantum rings under orthogonal electric and magnetic fields have been theoretically studied. The Schrödinger wave equation was solved using the finite element method within the effective mass approximation. A Stark effect with anomalous oscillatory behavior was observed for electric field strengths less than 10 kV/cm. The threading magnetic field leads to the formation of damped oscillations in the absorption coefficient peaks, which are closely related both to the Aharonov-Bohm oscillations and to a shift of the absorption peaks towards blue or red, depending on the dimensions and morphology of the central crater. Our model is sufficiently flexible such that several results appear as particular cases of the quantum ring with a rectangular central crater.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"526 ","pages":"Article 129980"},"PeriodicalIF":2.3,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1016/j.physleta.2024.129987
Ehsan Koushki
The main interaction of laser beam with materials is to create a temperature distribution, which is the introduction to investigating effects such as thermal-lensing, nonlinear absorption and refraction, and laser-induced damage effects. The correct prediction of this temperature profile can be important in the accurate calculation of thermal expansion volumetric stresses that cause optical aberrations in optical devices and photonic and laser materials. In this letter, new approach has been used to solve the heat equation of laser beam radiation to a thin sample and an exact solution for the time-independent heat equation in a laser-irradiated sample was obtained. Considering appropriate boundary conditions, the steady-state temperature distribution without any approximation was obtained which includes the lower incomplete gamma function. Based on the temperature distribution, the nonlinear changes of absorption and refractive indexes resulting from thermal effects can be accurately calculated. This model was extended for both Gaussian and top-hat beams.
{"title":"Analytical solution of steady state heat equation in nonlinear thermal-lensing effect","authors":"Ehsan Koushki","doi":"10.1016/j.physleta.2024.129987","DOIUrl":"10.1016/j.physleta.2024.129987","url":null,"abstract":"<div><div>The main interaction of laser beam with materials is to create a temperature distribution, which is the introduction to investigating effects such as thermal-lensing, nonlinear absorption and refraction, and laser-induced damage effects. The correct prediction of this temperature profile can be important in the accurate calculation of thermal expansion volumetric stresses that cause optical aberrations in optical devices and photonic and laser materials. In this letter, new approach has been used to solve the heat equation of laser beam radiation to a thin sample and an exact solution for the time-independent heat equation in a laser-irradiated sample was obtained. Considering appropriate boundary conditions, the steady-state temperature distribution without any approximation was obtained which includes the lower incomplete gamma function. Based on the temperature distribution, the nonlinear changes of absorption and refractive indexes resulting from thermal effects can be accurately calculated. This model was extended for both Gaussian and top-hat beams.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"527 ","pages":"Article 129987"},"PeriodicalIF":2.3,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-15DOI: 10.1016/j.physleta.2024.129977
Haroon , M.A.H. Ahsan
Exact eigenstates of the parallel coupled double quantum dots attached to the non-interacting leads taken in the zero-bandwidth limit (effectively quadruple quantum dots) are analytically obtained in each particle and spin subspace. The ground state of the half-filled system is determined within a four-dimensional subspace of the twenty-dimensional Hilbert space. The effects of tunable parameters, such as quantum dot energy levels, interdot tunneling, ondot and interdot Coulomb interactions, on spin-spin correlation and dot occupancies are analyzed. In the parameter space defined by interdot tunneling and ondot Coulomb interaction, the tunnel-coupled dots exhibit both ferromagnetic and antiferromagnetic correlations, suggesting suitability for singlet-triplet qubits in quantum computing. A critical dependency of interdot tunneling on ondot Coulomb interaction leads to a transition from ferromagnetic to antiferromagnetic correlation as interdot tunneling increases. These correlations persist even without interdot tunneling via indirect exchange through the leads, with the interdot Coulomb interaction significantly influencing this dependency.
{"title":"Electronic correlations in parallel-coupled double quantum dot system: An exact analytical approach","authors":"Haroon , M.A.H. Ahsan","doi":"10.1016/j.physleta.2024.129977","DOIUrl":"10.1016/j.physleta.2024.129977","url":null,"abstract":"<div><div>Exact eigenstates of the parallel coupled double quantum dots attached to the non-interacting leads taken in the zero-bandwidth limit (effectively quadruple quantum dots) are analytically obtained in each particle and spin subspace. The ground state of the half-filled system is determined within a four-dimensional subspace of the twenty-dimensional Hilbert space. The effects of tunable parameters, such as quantum dot energy levels, interdot tunneling, ondot and interdot Coulomb interactions, on spin-spin correlation and dot occupancies are analyzed. In the parameter space defined by interdot tunneling and ondot Coulomb interaction, the tunnel-coupled dots exhibit both ferromagnetic and antiferromagnetic correlations, suggesting suitability for singlet-triplet qubits in quantum computing. A critical dependency of interdot tunneling on ondot Coulomb interaction leads to a transition from ferromagnetic to antiferromagnetic correlation as interdot tunneling increases. These correlations persist even without interdot tunneling via indirect exchange through the leads, with the interdot Coulomb interaction significantly influencing this dependency.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"527 ","pages":"Article 129977"},"PeriodicalIF":2.3,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-15DOI: 10.1016/j.physleta.2024.129988
Shi-cheng Xiao, Gui-ping Tang, Zhi-qiang Fan
Based on first-principles calculations, the potential of the H-VS2/Blue P heterojunction composite as a lithium-ion battery anode is systematically investigated. This heterojunction composite enhances the stability of the VS2 structure and increases its overall mechanical strength.The Young's modulus of the composite is 144.69 N/m, markedly exceeding that of the single layer. Furthermore, it modifies the electronic properties of the Blue P monolayer, converting it from an insulating to a metallic state.
The H-VS2/Blue P heterojunction composite exhibits a high lithium adsorption energy of 4.34 eV and a low diffusion barrier of 0.15–0.19 eV, facilitating rapid lithium-ion migration during charge/discharge cycles. And the theoretical capacity of the heterojunction composite is up to 1211 mAh/g. The combination of elevated adsorption energy, low diffusion barrier, and high theoretical capacity indicates that the H-VS2/Blue P heterojunction composite is a highly promising anode material for lithium-ion batteries.
基于第一原理计算，系统研究了 H-VS2/Blue P 异质结复合材料作为锂离子电池负极的潜力。这种异质结复合材料增强了 VS2 结构的稳定性，提高了其整体机械强度。复合材料的杨氏模量为 144.69 N/m，明显超过了单层材料。此外，它还改变了蓝 P 单层的电子特性，使其从绝缘状态转变为金属状态。H-VS2/蓝 P 异质结复合材料具有 4.34 eV 的高锂吸附能和 0.15-0.19 eV 的低扩散势垒，有利于锂离子在充放电循环中快速迁移。异质结复合材料的理论容量高达 1211 mAh/g。高吸附能、低扩散势垒和高理论容量的组合表明 H-VS2/Blue P 异质结复合材料是一种极具潜力的锂离子电池负极材料。
{"title":"VS2/ Blue Phosphorus composites for high speed lithium ions storage","authors":"Shi-cheng Xiao, Gui-ping Tang, Zhi-qiang Fan","doi":"10.1016/j.physleta.2024.129988","DOIUrl":"10.1016/j.physleta.2024.129988","url":null,"abstract":"<div><div>Based on first-principles calculations, the potential of the H-VS<sub>2</sub>/Blue P heterojunction composite as a lithium-ion battery anode is systematically investigated. This heterojunction composite enhances the stability of the VS<sub>2</sub> structure and increases its overall mechanical strength.The Young's modulus of the composite is 144.69 N/m, markedly exceeding that of the single layer. Furthermore, it modifies the electronic properties of the Blue P monolayer, converting it from an insulating to a metallic state.</div><div>The H-VS<sub>2</sub>/Blue P heterojunction composite exhibits a high lithium adsorption energy of 4.34 eV and a low diffusion barrier of 0.15–0.19 eV, facilitating rapid lithium-ion migration during charge/discharge cycles. And the theoretical capacity of the heterojunction composite is up to 1211 mAh/g. The combination of elevated adsorption energy, low diffusion barrier, and high theoretical capacity indicates that the H-VS<sub>2</sub>/Blue P heterojunction composite is a highly promising anode material for lithium-ion batteries.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"527 ","pages":"Article 129988"},"PeriodicalIF":2.3,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-13DOI: 10.1016/j.physleta.2024.129982
Priyanka Babu, Jaivardhan Sinha
In this work, using micromagnetic simulations we study the mechanism involved in the conversion of a 360° domain wall into stable pairs of bimeron (Q = +1) and antibimeron (Q = -1) in a ferromagnetic background when it is subjected to Zhang Li type of spin transfer torque. We show that the time scales associated with the conversion process can be significantly reduced by applying out of plane bias field. In particular, choosing a constant inclination angle and increasing the intensity of bias field aids in reducing the energy barrier required to stabilize the spin textures. Similarly, for a constant bias field intensity, varying the inclination angle between 0° to 40° reveals that the time required to stabilize the first bimeron is reduced by ∼ 3 ns. Further, tailoring the strength of in-plane current density as well as effective uniaxial anisotropy leads to faster conversion of domain wall to bimerons.
{"title":"Spin transfer torque and field driven 360° domain wall to bimeron conversion","authors":"Priyanka Babu, Jaivardhan Sinha","doi":"10.1016/j.physleta.2024.129982","DOIUrl":"10.1016/j.physleta.2024.129982","url":null,"abstract":"<div><div>In this work, using micromagnetic simulations we study the mechanism involved in the conversion of a 360° domain wall into stable pairs of bimeron (<em>Q</em> = +1) and antibimeron (<em>Q</em> = -1) in a ferromagnetic background when it is subjected to Zhang Li type of spin transfer torque. We show that the time scales associated with the conversion process can be significantly reduced by applying out of plane bias field. In particular, choosing a constant inclination angle and increasing the intensity of bias field aids in reducing the energy barrier required to stabilize the spin textures. Similarly, for a constant bias field intensity, varying the inclination angle between 0° to 40° reveals that the time required to stabilize the first bimeron is reduced by ∼ 3 ns. Further, tailoring the strength of in-plane current density as well as effective uniaxial anisotropy leads to faster conversion of domain wall to bimerons.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"527 ","pages":"Article 129982"},"PeriodicalIF":2.3,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-12DOI: 10.1016/j.physleta.2024.129981
Yuchen Wang, Qiaobang Xiang, Qi Zhou, Ningbo Liao
Developing sensitive gas sensor is essential for preventing carbon monoxide poisoning. Current experiments demonstrated excellent performance of Ni-MoO3 as gas sensor, however, atomic-scale sensing mechanism that is critical for developing novel gas sensor is not explored. In this study, adsorption and electronic properties of CH4, H2, CO, H2O, NH3, H2S gases on Ni-doped MoO3 are calculated by first-principles. The CO/Ni-MoO3 system presents the greatest energy of adsorption, the most significant changes in the band gap, and the largest differential charge density, together with the smallest adsorption distance, indicating an intense interaction and chemisorption between CO and Ni-MoO3. Upon the CO adsorption, density of state for Ni-MoO3 descends to a lower energy level, and the increasing in DOS near Fermi level results in a substantial alteration in conductivity. It can be deduced that the Ni-MoO3 system exhibits sensitive and selective detection toward CO gas.
开发灵敏的气体传感器对于预防一氧化碳中毒至关重要。目前的实验表明，Ni-MoO3 作为气体传感器具有优异的性能，然而，对于开发新型气体传感器至关重要的原子尺度传感机制尚未得到探索。本研究通过第一性原理计算了 CH4、H2、CO、H2O、NH3、H2S 气体在掺杂镍的 MoO3 上的吸附和电子特性。CO/Ni-MoO3体系的吸附能量最大、带隙变化最显著、电荷差密度最大、吸附距离最小，表明CO与Ni-MoO3之间存在强烈的相互作用和化学吸附。吸附 CO 后，Ni-MoO3 的状态密度下降到较低的能级，费米级附近 DOS 的增大导致电导率的大幅改变。由此可以推断，Ni-MoO3 系统对一氧化碳气体具有灵敏的选择性探测能力。
{"title":"First-principles prediction of Ni-MoO3 as selective and sensitive sensor for detecting CO over CH4, H2, H2O, NH3, H2S gases","authors":"Yuchen Wang, Qiaobang Xiang, Qi Zhou, Ningbo Liao","doi":"10.1016/j.physleta.2024.129981","DOIUrl":"10.1016/j.physleta.2024.129981","url":null,"abstract":"<div><div>Developing sensitive gas sensor is essential for preventing carbon monoxide poisoning. Current experiments demonstrated excellent performance of Ni-MoO<sub>3</sub> as gas sensor, however, atomic-scale sensing mechanism that is critical for developing novel gas sensor is not explored. In this study, adsorption and electronic properties of CH<sub>4</sub>, H<sub>2</sub>, CO, H<sub>2</sub>O, NH<sub>3</sub>, H<sub>2</sub>S gases on Ni-doped MoO<sub>3</sub> are calculated by first-principles. The CO/Ni-MoO<sub>3</sub> system presents the greatest energy of adsorption, the most significant changes in the band gap, and the largest differential charge density, together with the smallest adsorption distance, indicating an intense interaction and chemisorption between CO and Ni-MoO<sub>3</sub>. Upon the CO adsorption, density of state for Ni-MoO<sub>3</sub> descends to a lower energy level, and the increasing in DOS near Fermi level results in a substantial alteration in conductivity. It can be deduced that the Ni-MoO<sub>3</sub> system exhibits sensitive and selective detection toward CO gas.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"526 ","pages":"Article 129981"},"PeriodicalIF":2.3,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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