This study examines resistive switching in a Cu/ZnO/ITO structure, uncovering an anomalous phenomenon that provides insights into the mechanisms of parallel conducting filaments in ZnO thin films. The current–voltage (I–V) characteristics exhibit a sharp switch at a positive threshold voltage around 2 V, transitioning from a high resistance pristine state to a low resistance state, interpreted as the formation of a Cu filament via electrochemical metallization. However, after this forming process, the device remains in the low resistance state and cannot reset to a high resistance state in either polarity of the applied voltage, suggesting the presence of a strong, unbreakable Cu filament after the forming process. What makes this phenomenon anomalous is the observed weak bipolar resistive switching in the cycles following the forming cycle, despite the presence of the Cu filament. The I–V characteristics of forward- and reverse-bias sweeps suggest that the weak bipolar resistive switching results from an additional filament formed in parallel with the existing unbreakable Cu filament. Using a parallel conducting filaments model, the resistivity of this additional filament is calculated to be ∼10−7–10−5 Ω m, indicating that this filament is likely generated by oxygen vacancies rather than metal atoms in the ZnO films.
这项研究考察了铜/氧化锌/氧化钛结构中的电阻开关，发现了一种异常现象，为了解氧化锌薄膜中平行导电丝的机制提供了启示。电流-电压（I-V）特性在 2 V 左右的正阈值电压时出现急剧切换，从高电阻原始状态过渡到低电阻状态，这被解释为通过电化学金属化形成了铜丝。然而，在这一形成过程之后，该器件仍处于低电阻状态，无论施加哪种极性的电压，都无法复位到高电阻状态，这表明在形成过程之后，存在着坚固、牢不可破的铜丝。使这一现象反常的是，尽管存在铜丝，但在成型周期之后的周期中观察到了微弱的双极电阻开关。正向和反向偏压扫描的 I-V 特性表明，微弱的双极电阻开关是由于与现有的不易破碎铜丝平行形成的附加铜丝造成的。利用平行导电丝模型，计算出这条附加丝的电阻率为 ∼10-7-10-5 Ω m，这表明这条附加丝很可能是由氧化锌薄膜中的氧空位而不是金属原子产生的。
{"title":"Parallel conducting filaments in resistive switching ZnO thin films","authors":"Tai-Min Liu, Zong-Wei Wu, Ting-An Chien, Pin-Qian Yang, Hua-Shu Hsu, Fang-Yuh Lo","doi":"10.1063/5.0232595","DOIUrl":"https://doi.org/10.1063/5.0232595","url":null,"abstract":"This study examines resistive switching in a Cu/ZnO/ITO structure, uncovering an anomalous phenomenon that provides insights into the mechanisms of parallel conducting filaments in ZnO thin films. The current–voltage (I–V) characteristics exhibit a sharp switch at a positive threshold voltage around 2 V, transitioning from a high resistance pristine state to a low resistance state, interpreted as the formation of a Cu filament via electrochemical metallization. However, after this forming process, the device remains in the low resistance state and cannot reset to a high resistance state in either polarity of the applied voltage, suggesting the presence of a strong, unbreakable Cu filament after the forming process. What makes this phenomenon anomalous is the observed weak bipolar resistive switching in the cycles following the forming cycle, despite the presence of the Cu filament. The I–V characteristics of forward- and reverse-bias sweeps suggest that the weak bipolar resistive switching results from an additional filament formed in parallel with the existing unbreakable Cu filament. Using a parallel conducting filaments model, the resistivity of this additional filament is calculated to be ∼10−7–10−5 Ω m, indicating that this filament is likely generated by oxygen vacancies rather than metal atoms in the ZnO films.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"116 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252501","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}
There is a pronounced coupling vibration between the catenary and pantograph during operation for high-speed railways. In this paper, a pantograph–catenary coupling vibration model is constructed to investigate the vibration characteristics under various working conditions. Two different types of catenaries (simple and elastic chain types) are simulated and compared using the finite element method. The pantograph is simplified into a mass–spring–damping combination member, the contact and messenger wires are set to linear beam cells, and the dropper and stitch wire are set to truss cells. The results suggest that the vibration characteristics of the two types of catenaries and pantograph exhibit different trends. The maximum stresses of the messenger wire, dropper, and contact wire do not follow a monotonically increasing trend with the train speed. The maximum stress of the messenger wire under the simple chain type of catenary is higher when the initial contact force increases from 80 to 120 N. However, the maximum stress under the elastic chain type of catenary is higher when the initial contact force is 60 or 140 N. Except for the initial contact force of 140 N, the maximum stresses of the dropper and contact wire under the simple chain type of catenary are lower than those under the elastic chain type. This work provides a valuable reference for optimizing the design of pantograph–catenary systems.
{"title":"Numerical analysis of pantograph–catenary coupling vibration for high-speed railways","authors":"Like Pan, Peihuo Peng, Liming Chen, Fan He","doi":"10.1063/5.0219474","DOIUrl":"https://doi.org/10.1063/5.0219474","url":null,"abstract":"There is a pronounced coupling vibration between the catenary and pantograph during operation for high-speed railways. In this paper, a pantograph–catenary coupling vibration model is constructed to investigate the vibration characteristics under various working conditions. Two different types of catenaries (simple and elastic chain types) are simulated and compared using the finite element method. The pantograph is simplified into a mass–spring–damping combination member, the contact and messenger wires are set to linear beam cells, and the dropper and stitch wire are set to truss cells. The results suggest that the vibration characteristics of the two types of catenaries and pantograph exhibit different trends. The maximum stresses of the messenger wire, dropper, and contact wire do not follow a monotonically increasing trend with the train speed. The maximum stress of the messenger wire under the simple chain type of catenary is higher when the initial contact force increases from 80 to 120 N. However, the maximum stress under the elastic chain type of catenary is higher when the initial contact force is 60 or 140 N. Except for the initial contact force of 140 N, the maximum stresses of the dropper and contact wire under the simple chain type of catenary are lower than those under the elastic chain type. This work provides a valuable reference for optimizing the design of pantograph–catenary systems.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"208 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252503","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}
The significance of maintaining the surface stability of the In2O3 catalyst in the conversion of CO2 to methanol through hydrogenation cannot be overstated. To improve surface stability, doping with metal oxides is usually employed. To explore high-efficiency In2O3 based catalysts, density functional theory calculations were utilized to explore the effects of doping CuO, Co2O3, NiO, TiO2, HfO2, Nb2O3, Ta2O5, and CeO2 on the stability of the In2O3(110) surface. It was found that in a CO atmosphere, the crucial step in determining the creation of oxygen vacancies on the In2O3 plane occurred during the desorption of CO2 from the vacancy location. The results indicate that doping CuO, Co2O3, NiO, Nb2O3, Ta2O5, and CeO2 on the In2O3(110) surface promotes the reduction process through the reaction of CO with the O atoms on the surface, resulting in reduced surface stability. Conversely, the doping of Ti and Hf can raise the reaction energy barriers for CO reacting with the O atoms on the surface and enhance CO2 molecule adsorption on vacant sites, thereby suggesting the potential of TiO2 and HfO2 as effective modifiers to improve the efficiency and durability of the In2O3 catalyst. Furthermore, it is crucial to enhance its stability by modifying the density of the electron cloud or Fermi level of the In2O3 catalyst.
在通过氢化将二氧化碳转化为甲醇的过程中，保持 In2O3 催化剂表面稳定性的重要性怎么强调都不过分。为了提高表面稳定性，通常会采用掺杂金属氧化物的方法。为了探索基于 In2O3 的高效催化剂，研究人员利用密度泛函理论计算探讨了掺杂 CuO、Co2O3、NiO、TiO2、HfO2、Nb2O3、Ta2O5 和 CeO2 对 In2O3(110) 表面稳定性的影响。研究发现，在一氧化碳气氛中，决定 In2O3 表面产生氧空位的关键步骤发生在 CO2 从空位位置解吸的过程中。结果表明，在 In2O3（110）表面掺杂 CuO、Co2O3、NiO、Nb2O3、Ta2O5 和 CeO2 会通过 CO 与表面的 O 原子反应促进还原过程，导致表面稳定性降低。相反，Ti 和 Hf 的掺杂可以提高 CO 与表面 O 原子反应的反应能垒，增强 CO2 分子在空位上的吸附，从而表明 TiO2 和 HfO2 有可能成为有效的改性剂，提高 In2O3 催化剂的效率和耐用性。此外，通过改变 In2O3 催化剂的电子云密度或费米水平来提高其稳定性也至关重要。
{"title":"The effects of metal oxides doping on the surface stability of In2O3 for CO2 hydrogenation","authors":"Xingtang Xu, Yanwei Li, Guang Sun, Jianliang Cao, Yan Wang, Xulong Qin","doi":"10.1063/5.0224256","DOIUrl":"https://doi.org/10.1063/5.0224256","url":null,"abstract":"The significance of maintaining the surface stability of the In2O3 catalyst in the conversion of CO2 to methanol through hydrogenation cannot be overstated. To improve surface stability, doping with metal oxides is usually employed. To explore high-efficiency In2O3 based catalysts, density functional theory calculations were utilized to explore the effects of doping CuO, Co2O3, NiO, TiO2, HfO2, Nb2O3, Ta2O5, and CeO2 on the stability of the In2O3(110) surface. It was found that in a CO atmosphere, the crucial step in determining the creation of oxygen vacancies on the In2O3 plane occurred during the desorption of CO2 from the vacancy location. The results indicate that doping CuO, Co2O3, NiO, Nb2O3, Ta2O5, and CeO2 on the In2O3(110) surface promotes the reduction process through the reaction of CO with the O atoms on the surface, resulting in reduced surface stability. Conversely, the doping of Ti and Hf can raise the reaction energy barriers for CO reacting with the O atoms on the surface and enhance CO2 molecule adsorption on vacant sites, thereby suggesting the potential of TiO2 and HfO2 as effective modifiers to improve the efficiency and durability of the In2O3 catalyst. Furthermore, it is crucial to enhance its stability by modifying the density of the electron cloud or Fermi level of the In2O3 catalyst.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"29 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252494","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}
V. Kavimani, P. M. Gopal, V. Sivamaran, Sameer Algburi, Debabrata Barik, Prabhu Paramasivam, Abdullah H. Alsabhan, Shamshad Alam
In this work, a newly discovered biomedical grade Magnesium–Lithium–Strontium (Mg–Li–Sr) alloy is machined using electrochemical machining technology. Two main output constraints employed on the research project to evaluate machinability are surface roughness (Ra) and material removal rate (MRR). Changing feed rate (FR), current, electrolyte concentration (EC), and voltage is required in order to carry out experimental experiments. The trials were designed using the Taguchi method. The ANOVA findings show that current is the most significant factor, after voltage as the most significant input parameter in regulating Ra and MRR. The ideal parameter configuration for the CRITIC-linked Deng’s similarity approach method was 5 V, 1 A of current, 0.4 mm/min of FR, and 20 g/l of EC. The final product was a 0.0323 mm/min MRR and a 2.61 μm surface roughness. Furthermore, the response variables are anticipated using the adaptive neuro-fuzzy Inference System, which finally results in predictions that are very similar to the experimental results.
{"title":"Experimental examination on electrochemical micro-machining of Mg–Li–Sr biomedical alloy: Application of ANOVA, Deng’s similarity, and ANFIS for effective modeling optimization","authors":"V. Kavimani, P. M. Gopal, V. Sivamaran, Sameer Algburi, Debabrata Barik, Prabhu Paramasivam, Abdullah H. Alsabhan, Shamshad Alam","doi":"10.1063/5.0220057","DOIUrl":"https://doi.org/10.1063/5.0220057","url":null,"abstract":"In this work, a newly discovered biomedical grade Magnesium–Lithium–Strontium (Mg–Li–Sr) alloy is machined using electrochemical machining technology. Two main output constraints employed on the research project to evaluate machinability are surface roughness (Ra) and material removal rate (MRR). Changing feed rate (FR), current, electrolyte concentration (EC), and voltage is required in order to carry out experimental experiments. The trials were designed using the Taguchi method. The ANOVA findings show that current is the most significant factor, after voltage as the most significant input parameter in regulating Ra and MRR. The ideal parameter configuration for the CRITIC-linked Deng’s similarity approach method was 5 V, 1 A of current, 0.4 mm/min of FR, and 20 g/l of EC. The final product was a 0.0323 mm/min MRR and a 2.61 μm surface roughness. Furthermore, the response variables are anticipated using the adaptive neuro-fuzzy Inference System, which finally results in predictions that are very similar to the experimental results.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"15 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252497","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}
B. Langa, D. Sapkota, I. Lainez, R. Haight, B. Srijanto, L. Feldman, H. Hijazi, X. Zhu, L. Hu, M. Kim, K. Sardashti
Hybrid superconductor–semiconductor materials systems are promising candidates for quantum computing applications. Their integration into superconducting electronics has enabled on-demand voltage tunability at millikelvin temperatures. Ge quantum wells have been among the semiconducting platforms interfaced with superconducting Al to realize voltage tunable Josephson junctions. Here, we explore Nb as a superconducting material in direct contact with Ge channels by focusing on the solid-state reactions at the Nb/Ge interfaces. We employ Nb evaporation at cryogenic temperatures (∼100 K) to establish a baseline structure with atomically and chemically abrupt Nb/Ge interfaces. By conducting systematic photoelectron spectroscopy and transport measurements on Nb/Ge samples across varying annealing temperatures, we elucidated the influence of Ge out-diffusion on the ultimate performance of superconducting electronics. This study underlines the need for low-temperature growth to minimize chemical intermixing and band bending at the Nb/Ge interfaces.
混合超导体-半导体材料系统是量子计算应用的理想候选材料。将它们集成到超导电子器件中，可以在毫开尔文温度下实现按需电压可调。Ge 量子阱是与超导 Al 相连接的半导体平台之一，可实现电压可调的约瑟夫森结。在这里，我们通过重点研究铌/锗界面的固态反应，探索铌作为超导材料与 Ge 沟道的直接接触。我们采用在低温（∼100 K）下蒸发铌的方法，建立了具有原子和化学突变铌/锗界面的基线结构。通过对不同退火温度下的 Nb/Ge 样品进行系统的光电子能谱和传输测量，我们阐明了 Ge 外扩散对超导电子器件最终性能的影响。这项研究强调了低温生长的必要性，以尽量减少铌/锗界面上的化学混杂和带弯曲。
{"title":"Solid-state reactions at niobium–germanium interfaces in hybrid quantum electronics","authors":"B. Langa, D. Sapkota, I. Lainez, R. Haight, B. Srijanto, L. Feldman, H. Hijazi, X. Zhu, L. Hu, M. Kim, K. Sardashti","doi":"10.1063/5.0221366","DOIUrl":"https://doi.org/10.1063/5.0221366","url":null,"abstract":"Hybrid superconductor–semiconductor materials systems are promising candidates for quantum computing applications. Their integration into superconducting electronics has enabled on-demand voltage tunability at millikelvin temperatures. Ge quantum wells have been among the semiconducting platforms interfaced with superconducting Al to realize voltage tunable Josephson junctions. Here, we explore Nb as a superconducting material in direct contact with Ge channels by focusing on the solid-state reactions at the Nb/Ge interfaces. We employ Nb evaporation at cryogenic temperatures (∼100 K) to establish a baseline structure with atomically and chemically abrupt Nb/Ge interfaces. By conducting systematic photoelectron spectroscopy and transport measurements on Nb/Ge samples across varying annealing temperatures, we elucidated the influence of Ge out-diffusion on the ultimate performance of superconducting electronics. This study underlines the need for low-temperature growth to minimize chemical intermixing and band bending at the Nb/Ge interfaces.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"37 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252496","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}
Renjie Shi, Liming Li, Shubin Zheng, Yizhou Mao, Xiaoxue An
Detecting pantographs remains a challenging task due to complex scenes, variable weather conditions, and noise interference. Existing pantograph detection methods struggle to effectively segment the complete shape of the pantograph from intricate backgrounds and adverse weather, and they often exhibit inadequate real-time performance. To address these challenges, we propose a novel pantograph segmentation method that leverages a deep learning multi-scale strip pooling attention mechanism. Our approach utilizes the PidNet semantic segmentation network as the baseline architecture, while we introduce a newly designed multi-scale strip pooling attention mechanism specifically for the detail extraction branch. The multi-scale strip convolution branch effectively extracts the pantograph pixel-level detail features, while the pooling branch effectively extracts the macroscopic features of the pantograph. The unique linear interpolation method effectively mitigates the influence of weather, enhancing segmentation accuracy while maintaining a lightweight structure. In the context aggregation branch, a multi-scale context aggregation module utilizing gated convolution has been developed to replace the original network’s module, which possesses strong pantograph positioning capabilities. In comparison to existing pantograph detection methods, our model demonstrates the ability to accurately segment the pantograph with a clearly defined shape, effectively filter out extraneous background noise, and exhibit high robustness to variations in illumination and weather conditions. In addition, a rich pantograph dataset was created, including various scenarios and weather conditions, which also enhanced the robustness of the model. When the IOU and accuracy are 92.91% and 96.04%, respectively, the inference speed can still exceed 30 FPS on a single 2080Ti GPU.
{"title":"Semantic segmentation algorithm for pantograph based on multi-scale strip pooling attention mechanism and application research","authors":"Renjie Shi, Liming Li, Shubin Zheng, Yizhou Mao, Xiaoxue An","doi":"10.1063/5.0230117","DOIUrl":"https://doi.org/10.1063/5.0230117","url":null,"abstract":"Detecting pantographs remains a challenging task due to complex scenes, variable weather conditions, and noise interference. Existing pantograph detection methods struggle to effectively segment the complete shape of the pantograph from intricate backgrounds and adverse weather, and they often exhibit inadequate real-time performance. To address these challenges, we propose a novel pantograph segmentation method that leverages a deep learning multi-scale strip pooling attention mechanism. Our approach utilizes the PidNet semantic segmentation network as the baseline architecture, while we introduce a newly designed multi-scale strip pooling attention mechanism specifically for the detail extraction branch. The multi-scale strip convolution branch effectively extracts the pantograph pixel-level detail features, while the pooling branch effectively extracts the macroscopic features of the pantograph. The unique linear interpolation method effectively mitigates the influence of weather, enhancing segmentation accuracy while maintaining a lightweight structure. In the context aggregation branch, a multi-scale context aggregation module utilizing gated convolution has been developed to replace the original network’s module, which possesses strong pantograph positioning capabilities. In comparison to existing pantograph detection methods, our model demonstrates the ability to accurately segment the pantograph with a clearly defined shape, effectively filter out extraneous background noise, and exhibit high robustness to variations in illumination and weather conditions. In addition, a rich pantograph dataset was created, including various scenarios and weather conditions, which also enhanced the robustness of the model. When the IOU and accuracy are 92.91% and 96.04%, respectively, the inference speed can still exceed 30 FPS on a single 2080Ti GPU.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"6 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252498","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}
Electronic structure calculations of atoms and molecules are considered to be a promising application for quantum computers. Two key algorithms, the quantum phase estimation (QPE) and the variational quantum eigensolver (VQE), have been extensively studied. The condition that the energy of a dimer consisting of two monomers separated by a large distance should be equal to twice the energy of a monomer, known as size consistency, is essential in quantum chemical calculations. Recently, we reported that the size consistency condition can be violated by Trotterization in the unitary coupled cluster singles and doubles ansatz in the VQE when employing molecular orbitals delocalized to the dimer [Sugisaki et al., J. Comput. Chem. 45, 2204 (2024)]. It is well known that the full configuration interaction (full-CI) energy is invariant to arbitrary rotations of molecular orbitals, and therefore, the QPE-based full-CI should theoretically satisfy the size consistency. However, Trotterization of the time evolution operator can break the size consistency conditions. In this work, we investigated whether size consistency can be maintained with Trotterization of the time evolution operator in QPE-based full-CI calculations. Our numerical simulations revealed that size consistency in the QPE-based full-CI is not automatically violated by using molecular orbitals delocalized to the dimer, but employing an appropriate Trotter decomposition condition is crucial to maintain size consistency. We also report on the acceleration of QPE simulations through the sequential addition of ancillary qubits.
{"title":"Does the full configuration interaction method based on quantum phase estimation with Trotter decomposition satisfy the size consistency condition?","authors":"Kenji Sugisaki","doi":"10.1063/5.0223661","DOIUrl":"https://doi.org/10.1063/5.0223661","url":null,"abstract":"Electronic structure calculations of atoms and molecules are considered to be a promising application for quantum computers. Two key algorithms, the quantum phase estimation (QPE) and the variational quantum eigensolver (VQE), have been extensively studied. The condition that the energy of a dimer consisting of two monomers separated by a large distance should be equal to twice the energy of a monomer, known as size consistency, is essential in quantum chemical calculations. Recently, we reported that the size consistency condition can be violated by Trotterization in the unitary coupled cluster singles and doubles ansatz in the VQE when employing molecular orbitals delocalized to the dimer [Sugisaki et al., J. Comput. Chem. 45, 2204 (2024)]. It is well known that the full configuration interaction (full-CI) energy is invariant to arbitrary rotations of molecular orbitals, and therefore, the QPE-based full-CI should theoretically satisfy the size consistency. However, Trotterization of the time evolution operator can break the size consistency conditions. In this work, we investigated whether size consistency can be maintained with Trotterization of the time evolution operator in QPE-based full-CI calculations. Our numerical simulations revealed that size consistency in the QPE-based full-CI is not automatically violated by using molecular orbitals delocalized to the dimer, but employing an appropriate Trotter decomposition condition is crucial to maintain size consistency. We also report on the acceleration of QPE simulations through the sequential addition of ancillary qubits.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"5 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252499","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}
This study addresses the magnetohydrodynamic flow of a squeezed ternary nanofluid between two horizontal parallel Riga plates. The importance of this problem lies in understanding the complex interactions between magnetic fields, nanofluid dynamics, and heat transfer, which are crucial for optimizing thermal management systems. This study utilizes a numerical approach, specifically a collocation method implemented in MATLAB, to solve the governing equations with high precision. Key results acquired indicate that the magnetic field and Riga plate actuator significantly enhance fluid velocity, whereas the variation in thermal conductivity, radiation, and viscous dissipation increases the temperature distribution. Quantitative analysis illustrates the impact of all these factors on skin friction and Nusselt number. Sensitivity analysis using the response surface methodology exhibits the conditions for optimized heat transfer. The novelty of this work lies in its comprehensive analysis of the magnetohydrodynamic flow in the presence of a microcantilever sensor, which provides deep understanding of optimization of heat transfer rates. This research offers a detailed examination of the combined effects of various physical phenomena and also validates them through graphical comparisons with existing studies.
{"title":"Numerical investigation and sensitivity analysis of MHD ternary nanofluid flow between perforated squeezed Riga plates under the surveillance of microcantilever sensor","authors":"Rajakumari Rammoorthi, Dhivya Mohanavel","doi":"10.1063/5.0218608","DOIUrl":"https://doi.org/10.1063/5.0218608","url":null,"abstract":"This study addresses the magnetohydrodynamic flow of a squeezed ternary nanofluid between two horizontal parallel Riga plates. The importance of this problem lies in understanding the complex interactions between magnetic fields, nanofluid dynamics, and heat transfer, which are crucial for optimizing thermal management systems. This study utilizes a numerical approach, specifically a collocation method implemented in MATLAB, to solve the governing equations with high precision. Key results acquired indicate that the magnetic field and Riga plate actuator significantly enhance fluid velocity, whereas the variation in thermal conductivity, radiation, and viscous dissipation increases the temperature distribution. Quantitative analysis illustrates the impact of all these factors on skin friction and Nusselt number. Sensitivity analysis using the response surface methodology exhibits the conditions for optimized heat transfer. The novelty of this work lies in its comprehensive analysis of the magnetohydrodynamic flow in the presence of a microcantilever sensor, which provides deep understanding of optimization of heat transfer rates. This research offers a detailed examination of the combined effects of various physical phenomena and also validates them through graphical comparisons with existing studies.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"4 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252500","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}
Mostafizur Rahaman, Mahmudul Hasan, Rayan Md. Moinuddin, Md. Nasirul Islam
Due to the negative environmental impact, the usage of lead in perovskite solar cells has been a matter of concern. Moreover, a suitable replacement of Pb with similar optoelectrical properties is hard to find. MAPbI3 is the most common material that has been studied for solar PV applications. Compared to MAPbI3, Cs2TiBr6 and MASnI3 have been less studied. In this study, their potential in solar cell applications has been investigated. Titanium and tin are two materials that have been used in numerous studies as an alternative to Pb-based perovskite. However, the lack of optimization and combinations of electron transport layer (ETL) and hole transport layer (HTL) material choices leave a lot to be desired. In this study, two different perovskite absorber layers, Cs2TiBr6 and MASnI3, have been simulated, optimized, and compared with Pb-based MAPbI3, where La-doped BaSnO3 is used as ETL and CuSbS2 as HTL in identical cell architectures. La-doped BaSnO3 is well known for its high electron mobility and excellent optical properties, which makes it an ideal candidate for ETL. On the other hand, CuSbS2 has appropriate band alignment with perovskite materials and has a high absorption profile to be used as HTL. The simulations were analyzed by optimizing key parameters like absorber layer thickness, defect density, and temperature. The optimized device architecture reached the power conversion efficiencies (PCE) of 29.45% for MASnI3, followed by MAPbI3 (22.47%) and Cs2TiBr6 (21.96%). The result indicates that high performance lead-free perovskite cells are very much possible through proper material selection and optimization.
{"title":"Numerical optimization of lead-based and lead-free absorber materials for perovskite solar cell (PSC) architectures: A SCAPS-1D simulation","authors":"Mostafizur Rahaman, Mahmudul Hasan, Rayan Md. Moinuddin, Md. Nasirul Islam","doi":"10.1063/5.0217486","DOIUrl":"https://doi.org/10.1063/5.0217486","url":null,"abstract":"Due to the negative environmental impact, the usage of lead in perovskite solar cells has been a matter of concern. Moreover, a suitable replacement of Pb with similar optoelectrical properties is hard to find. MAPbI3 is the most common material that has been studied for solar PV applications. Compared to MAPbI3, Cs2TiBr6 and MASnI3 have been less studied. In this study, their potential in solar cell applications has been investigated. Titanium and tin are two materials that have been used in numerous studies as an alternative to Pb-based perovskite. However, the lack of optimization and combinations of electron transport layer (ETL) and hole transport layer (HTL) material choices leave a lot to be desired. In this study, two different perovskite absorber layers, Cs2TiBr6 and MASnI3, have been simulated, optimized, and compared with Pb-based MAPbI3, where La-doped BaSnO3 is used as ETL and CuSbS2 as HTL in identical cell architectures. La-doped BaSnO3 is well known for its high electron mobility and excellent optical properties, which makes it an ideal candidate for ETL. On the other hand, CuSbS2 has appropriate band alignment with perovskite materials and has a high absorption profile to be used as HTL. The simulations were analyzed by optimizing key parameters like absorber layer thickness, defect density, and temperature. The optimized device architecture reached the power conversion efficiencies (PCE) of 29.45% for MASnI3, followed by MAPbI3 (22.47%) and Cs2TiBr6 (21.96%). The result indicates that high performance lead-free perovskite cells are very much possible through proper material selection and optimization.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"71 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252502","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}
In this study, we conducted an experiment in which a source material was sprayed onto a substrate with simultaneous N+ ion beam injections. Hexamethyldisiloxane (HMDSO) or tetraethyl orthosilicate (TEOS) was used as a source material. The energy of N+ ions was set at 100 eV. The substrate temperature was set at room temperature. As a result of each trial, a film was deposited on the substrate in both HMDSO and TEOS cases. The film was analyzed by x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy. We found that the film was silicon dioxide and nitrogen atoms (2–4 at. %) were included in the film. For comparison, a trial was also conducted in which hexamethyldigermane (HMDG) was sprayed onto a substrate with simultaneous 30 eV N+ ion beam injections. Although HMDG had no oxygen atoms in its molecule, XPS and FTIR results showed that the film was germanium oxide containing nitrogen (2 at. %).
在这项研究中，我们进行了一项实验，将源材料喷射到基底上，同时注入 N+ 离子束。我们使用六甲基二硅氧烷（HMDSO）或正硅酸四乙酯（TEOS）作为源材料。N+ 离子的能量设定为 100 eV。基底温度设定为室温。每次试验的结果都是在 HMDSO 和 TEOS 的基底上沉积出一层薄膜。通过 X 射线光电子能谱 (XPS) 和傅立叶变换红外光谱 (FTIR) 对薄膜进行了分析。我们发现薄膜是二氧化硅，其中含有氮原子（2-4%）。为了进行比较，我们还进行了一项试验，将六甲基二锗 (HMDG) 喷射到基底上，同时注入 30 eV N+ 离子束。虽然 HMDG 分子中没有氧原子，但 XPS 和傅立叶变换红外光谱结果表明，薄膜是含氮（2%）的氧化锗。
{"title":"Low-energy N+ ion beam induced chemical vapor deposition using tetraethyl orthosilicate, hexamethyldisiloxane, or hexamethyldigermane","authors":"Satoru Yoshimura, Takae Takeuchi, Masato Kiuchi","doi":"10.1063/5.0214908","DOIUrl":"https://doi.org/10.1063/5.0214908","url":null,"abstract":"In this study, we conducted an experiment in which a source material was sprayed onto a substrate with simultaneous N+ ion beam injections. Hexamethyldisiloxane (HMDSO) or tetraethyl orthosilicate (TEOS) was used as a source material. The energy of N+ ions was set at 100 eV. The substrate temperature was set at room temperature. As a result of each trial, a film was deposited on the substrate in both HMDSO and TEOS cases. The film was analyzed by x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy. We found that the film was silicon dioxide and nitrogen atoms (2–4 at. %) were included in the film. For comparison, a trial was also conducted in which hexamethyldigermane (HMDG) was sprayed onto a substrate with simultaneous 30 eV N+ ion beam injections. Although HMDG had no oxygen atoms in its molecule, XPS and FTIR results showed that the film was germanium oxide containing nitrogen (2 at. %).","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"9 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142185391","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：