Bach Do, Sina Jafari Ghalekohneh, Taiwo Adebiyi, Bo Zhao, Ruda Zhang
{"title":"Automated design of nonreciprocal thermal emitters via Bayesian optimization","authors":"Bach Do, Sina Jafari Ghalekohneh, Taiwo Adebiyi, Bo Zhao, Ruda Zhang","doi":"arxiv-2409.09192","DOIUrl":"https://doi.org/arxiv-2409.09192","url":null,"abstract":"Nonreciprocal thermal emitters that break Kirchhoff's law of thermal\u0000radiation promise exciting applications for thermal and energy applications.\u0000The design of the bandwidth and angular range of the nonreciprocal effect,\u0000which directly affects the performance of nonreciprocal emitters, typically\u0000relies on physical intuition. In this study, we present a general numerical\u0000approach to maximize the nonreciprocal effect. We choose doped magneto-optic\u0000materials and magnetic Weyl semimetal materials as model materials and focus on\u0000pattern-free multilayer structures. The optimization randomly starts from a\u0000less effective structure and incrementally improves the broadband\u0000nonreciprocity through the combination of Bayesian optimization and\u0000reparameterization. Optimization results show that the proposed approach can\u0000discover structures that can achieve broadband nonreciprocal emission at\u0000wavelengths from 5 to 40 micrometers using only a fewer layers, significantly\u0000outperforming current state-of-the-art designs based on intuition in terms of\u0000both performance and simplicity.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Subhrajit Mukherjee, Shuhua Wang, Dasari Venkatakrishnarao, Yaoju Tarn, Teymour Talha-Dean, Rainer Lee, Ivan A. Verzhbitskiy, Ding Huang, Abhishek Mishra, John Wellington John, Sarthak Das, Fabio Bussoloti, Thathsara D. Maddumapatabandi, Yee Wen Teh, Yee Sin Ang, Kuan Eng Johnson Goh, Chit Siong Lau
{"title":"Toward Phonon-Limited Transport in Two-Dimensional Electronics by Oxygen-Free Fabrication","authors":"Subhrajit Mukherjee, Shuhua Wang, Dasari Venkatakrishnarao, Yaoju Tarn, Teymour Talha-Dean, Rainer Lee, Ivan A. Verzhbitskiy, Ding Huang, Abhishek Mishra, John Wellington John, Sarthak Das, Fabio Bussoloti, Thathsara D. Maddumapatabandi, Yee Wen Teh, Yee Sin Ang, Kuan Eng Johnson Goh, Chit Siong Lau","doi":"arxiv-2409.08453","DOIUrl":"https://doi.org/arxiv-2409.08453","url":null,"abstract":"Future electronics require aggressive scaling of channel material thickness\u0000while maintaining device performance. Two-dimensional (2D) semiconductors are\u0000promising candidates, but despite over two decades of research, experimental\u0000performance still lags theoretical expectations. Here, we develop an\u0000oxygen-free approach to push the electrical transport of 2D field-effect\u0000transistors toward the theoretical phonon-limited intrinsic mobility. We\u0000achieve record carrier mobilities of 91 (132) cm2V-1s-1 for mono- (bi-) layer\u0000MoS2 transistors on SiO2 substrate. Statistics from over 60 devices confirm\u0000that oxygen-free fabrication enhances key figures of merit by more than an\u0000order of magnitude. While previous studies suggest that 2D transition metal\u0000dichalcogenides such as MoS2 and WS2 are stable in air, we show that short-term\u0000ambient exposure can degrade their device performance through irreversible\u0000oxygen chemisorption. This study emphasizes the criticality of avoiding oxygen\u0000exposure, offering guidance for device manufacturing for fundamental research\u0000and practical applications of 2D materials.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A new critical growth parameter and mechanistic model for SiC nanowire synthesis via Si substrate carbonization: the role of H$_2$/CH$_4$ gas flow ratio","authors":"Junghyun Koo, Chinkyo Kim","doi":"arxiv-2409.09233","DOIUrl":"https://doi.org/arxiv-2409.09233","url":null,"abstract":"SiC structures, including nanowires and films, can be effectively grown on Si\u0000substrates through carbonization. However, growth parameters other than\u0000temperature, which influence the preferential formation of SiC nanowires or\u0000films, have not yet been identified. In this work, we investigate SiC synthesis\u0000via Si carbonization using methane (CH$_4$) by varying the growth temperature\u0000and the hydrogen to methane gas flow ratio (H$_2$/CH$_4$). We demonstrate that\u0000adjusting these parameters allows for the preferential growth of SiC nanowires\u0000or films. Specifically, SiC nanowires are preferentially grown when the\u0000H$_2$/CH$_4$ ratio exceeds a specific threshold, which varies with the growth\u0000temperature, ranging between 1200$^circ$C and 1310$^circ$C. Establishing this\u0000precise growth window for SiC nanowires in terms of the H$_2$/CH$_4$ ratio and\u0000growth temperature provides new insights into the parameter-driven morphology\u0000of SiC. Furthermore, we propose a mechanistic model to explain the preferential\u0000growth of either SiC nanowires or films, based on the kinetics of gas-phase\u0000reactions and surface processes. These findings not only advance our\u0000understanding of SiC growth mechanisms but also pave the way for optimized\u0000fabrication strategies for SiC-based nanostructures.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Md. Moklesur Rahman, Md Kamal Hossain, Fateha Samad, Fysol Ibna Abbas
{"title":"A Systematic Investigation of PbSe Thermoelectric Material","authors":"Md. Moklesur Rahman, Md Kamal Hossain, Fateha Samad, Fysol Ibna Abbas","doi":"arxiv-2409.08716","DOIUrl":"https://doi.org/arxiv-2409.08716","url":null,"abstract":"The thermoelectric characteristics of lead selenium (PbSe) doped with gallium\u0000(Ga) are investigated in this study. When the lead sulfide (PbSe) is tuned with\u0000appropriate dopants, it exhibits satisfactory ZT values, hence making it a\u0000promising thermoelectric material. This study examines the electrical\u0000conductivity, Seebeck coefficient, thermal conductivity, and power factor of\u0000PbSe, with varying amounts of added Ga. Results indicate that incorporating Ga\u0000into PbSe improves its thermoelectric performance, with a maximum ZT value of\u0000approximately 1.2 at 873 K for the optimal doping concentration of 0.005 atomic\u0000percent. This improvement is attributed to the combined effects of increased\u0000electrical conductivity and reduced thermal conductivity. These findings\u0000suggest that Ga-doped PbSe is a promising candidate for mid-temperature\u0000thermoelectric applications.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Thermoelectrical potential and derivation of Kelvin relation for thermoelectric materials","authors":"Sikun Chen, Hongxin Zhu, Haidong Wang, Zengyuan Guo","doi":"arxiv-2409.08836","DOIUrl":"https://doi.org/arxiv-2409.08836","url":null,"abstract":"Current research on thermoelectricity is primarily focused on the exploration\u0000of materials with enhanced performance, resulting in a lack of fundamental\u0000understanding of the thermoelectric effect. Such circumstance is not conducive\u0000to the further improvement of the efficiency of thermoelectric conversion.\u0000Moreover, available physical images of the derivation of the Kelvin relations\u0000are ambiguous. Derivation processes are complex and need a deeper understanding\u0000of thermoelectric conversion phenomena. In this paper, a new physical quantity\u0000'thermoelectrical potential' from the physical nature of the thermoelectric\u0000conversion is proposed. The quantity is expressed as the product of the Seebeck\u0000coefficient and the absolute temperature, i.e., ST. Based on the\u0000thermoelectrical potential, we clarify the conversion of the various forms of\u0000energy in the thermoelectric effect by presenting a clear physical picture.\u0000Results from the analysis of the physical mechanism of the Seebeck effect\u0000indicate that the thermoelectrical potential, rather than the temperature\u0000gradient field, exerts a force on the charge carriers in the thermoelectric\u0000material. Based on thermoelectric potential, the Peltier effects at different\u0000material interfaces can be macroscopically described. The Kelvin relation is\u0000rederived using the proposed quantity, which simplified the derivation process\u0000and elucidated the physical picture of the thermoelectrical conversion.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shuaifeng Li, Yubin Oh, Seong Jae Choi, Panayotis G. Kevrekidis, Jinkyu Yang
{"title":"On-demand realization of topological states using Miura-folded metamaterials","authors":"Shuaifeng Li, Yubin Oh, Seong Jae Choi, Panayotis G. Kevrekidis, Jinkyu Yang","doi":"arxiv-2409.08064","DOIUrl":"https://doi.org/arxiv-2409.08064","url":null,"abstract":"Recent advancements in topological metamaterials have unveiled fruitful\u0000physics and numerous applications. Whereas initial efforts focus on achieving\u0000topologically protected edge states through principles of structural symmetry,\u0000the burgeoning field now aspires to customize topological states, tailoring\u0000their emergence and frequency. Here, our study presents the realization of\u0000topological phase transitions utilizing compliant mechanisms on the facets of\u0000Miura-folded metamaterials. This approach induces two opposite topological\u0000phases, leading to topological states at the interface. Moreover, we exploit\u0000the unique folding behavior of Miura-folded metamaterials to tune the frequency\u0000of topological states and dynamically toggle their presence. Our research not\u0000only paves the way for inducing topological phase transitions in Miura-folded\u0000structures but also enables the on-demand control of topological states, with\u0000promising applications in wave manipulation and vibration isolation.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Linqiang Xu, Yue Hu, Lianqiang Xu, Lin Xu, Qiuhui Li, Aili Wang, Chit Siong Lau, Jing Lu, Yee Sin Ang
{"title":"Ab Initio Device-Driven Screening of Sub-1-nm Thickness Oxide Semiconductors for Future CMOS Technology Nodes","authors":"Linqiang Xu, Yue Hu, Lianqiang Xu, Lin Xu, Qiuhui Li, Aili Wang, Chit Siong Lau, Jing Lu, Yee Sin Ang","doi":"arxiv-2409.08096","DOIUrl":"https://doi.org/arxiv-2409.08096","url":null,"abstract":"Ultrathin oxide semiconductors with sub-1-nm thickness are promising building\u0000blocks for ultrascaled field-effect transistor (FET) applications due to their\u0000resilience against short-channel effects, high air stability, and potential for\u0000low-energy device operation. However, the n-type dominance of ultrathin oxide\u0000FET has hindered their integration into complementary metal-oxide-semiconductor\u0000(CMOS) technology, which requires both n-and p-type devices. Here we develop an\u0000ab initio device-driven computational screening workflow to identify sub-1-nm\u0000thickness oxide semiconductors for sub-5-nm FET applications. We demonstrate\u0000that ultrathin CaO2, CaO, and SrO are compatible with p-type device operations\u0000under both high-performance (HP) and low-power (LP) requirements specified by\u0000the International Technology Roadmap of Semiconductors (ITRS), thereby\u0000expanding the limited family of p-type oxide semiconductors. Notably, CaO and\u0000SrO emerge as the first-of-kind sub-1-nm thickness oxide semiconductors capable\u0000of simultaneously meeting the ITRS HP and LP criteria for both n-and p-type\u0000devices. CaO and SrO FETs outperform many existing low-dimensional\u0000semiconductors, exhibiting scalability below 5-nm gate length. Our findings\u0000offer a pioneering effort in the ab initio, device-driven screening of sub-1-nm\u0000thickness oxide semiconductors, significantly broadening the material candidate\u0000pool for future CMOS technology nodes.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. O. Castro, B. Buyatti, D. Mercado, A. Di Donato, M. Quintero, M. Tortarolo
{"title":"Spike-timing-dependent-plasticity learning in a planar magnetic domain wall artificial synapsis","authors":"J. O. Castro, B. Buyatti, D. Mercado, A. Di Donato, M. Quintero, M. Tortarolo","doi":"arxiv-2409.08055","DOIUrl":"https://doi.org/arxiv-2409.08055","url":null,"abstract":"Future neuromorphic architectures will require millions of artificial\u0000synapses, making understanding the physical mechanisms behind their plasticity\u0000functionalities mandatory. In this work, we propose a simplified spin\u0000memristor, where the resistance can be controlled by magnetic field pulses,\u0000based on a Co/Pt multilayer with perpendicular magnetic anisotropy as a\u0000synapsis emulator. We demonstrate plasticity and spike time dependence\u0000plasticity (STDP) in this device and explored the underlying magnetic\u0000mechanisms using Kerr microscopy imaging and Hall magneto-transport\u0000measurements. A well-defined threshold for magnetization reversal and the\u0000continuous resistance states associated with the micromagnetic configuration\u0000are the basic properties allowing plasticity and STDP learning mechanisms in\u0000this device.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Dulski, E. Beyene, N. Chug, C. Curceanu, E. Czerwiński, M. Das, M. Gorgol, B. Jasińska, K. Kacprzak, Ł. Kapłon, G. Korcyl, T. Kozik, K. Kubat, D. Kumar, E. Lisowski, F. Lisowski, J. Mędrala-Sowa, S. Niedźwiecki, P. Pandey, S. Parzych, E. Perez del Rio, M. Rädler, S. Sharma, M. Skurzok, K. Tayefi, P. Tanty, E. Ł. Stępień, P. Moskal
{"title":"Nanoporosity imaging by positronium lifetime tomography","authors":"K. Dulski, E. Beyene, N. Chug, C. Curceanu, E. Czerwiński, M. Das, M. Gorgol, B. Jasińska, K. Kacprzak, Ł. Kapłon, G. Korcyl, T. Kozik, K. Kubat, D. Kumar, E. Lisowski, F. Lisowski, J. Mędrala-Sowa, S. Niedźwiecki, P. Pandey, S. Parzych, E. Perez del Rio, M. Rädler, S. Sharma, M. Skurzok, K. Tayefi, P. Tanty, E. Ł. Stępień, P. Moskal","doi":"arxiv-2409.07963","DOIUrl":"https://doi.org/arxiv-2409.07963","url":null,"abstract":"Positron Annihilation Lifetime Spectroscopy (PALS) is a well-established\u0000non-destructive technique used for nanostructural characterization of porous\u0000materials. It is based on the annihilation of a positron and an electron. Mean\u0000positron lifetime in the material depends on the free voids size and molecular\u0000environment, allowing the study of porosity and structural transitions in the\u0000nanometer scale. We have developed a novel method enabling spatially resolved\u0000PALS, thus providing tomography of nanostructural characterization of an\u0000extended object. Correlating space (position) and structural (lifetime)\u0000information brings new insight in materials studies, especially in the\u0000characterization of the purity and pore distribution. For the first time, a\u0000porosity image using stationary positron sources for the simultaneous\u0000measurement of the porous polymers XAD4, silica aerogel powder IC3100, and\u0000polyvinyl toluene scintillator PVT by the J-PET tomograph is demonstrated","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaofan Cai, Ruichang Chen, Xu Gao, Meili Yuan, Haixia Hu, Hang Yin, Yuanyuan Qu, Yang Tan, Feng Chen
{"title":"Hopping Transfer Optimizes Avalanche Multiplication in Molybdenum Disulfide","authors":"Xiaofan Cai, Ruichang Chen, Xu Gao, Meili Yuan, Haixia Hu, Hang Yin, Yuanyuan Qu, Yang Tan, Feng Chen","doi":"arxiv-2409.07677","DOIUrl":"https://doi.org/arxiv-2409.07677","url":null,"abstract":"Recently, avalanche multiplication has been observed in TMDC-based FETs,\u0000enhancing sensor performance with high sensitivity. However, the high voltage\u0000required for operation can damage the FETs, making it crucial to reduce the\u0000breakdown voltage for effective sensing applications. Here, we demonstrate that\u0000the utilization of hopping transfer induced by high-density defects can\u0000effectively reduce the breakdown voltage in TMDCs FETs. By substituting oxygen\u0000atoms for sulfur atoms in a monolayer of MoS2, we create MoS2-xOx, with x\u0000carefully adjusted within the range of 0 to 0.51. Oxygen doping reduces the\u0000bandgap of TMDCs and enhances ion collision rates. Moreover, higher levels of\u0000oxygen doping (x > 0.41) in MoS2-xOx exhibit nearest-neighbor hopping behavior,\u0000leading to a significant enhancement in electron mobility. These improvements\u0000result in a decrease in the breakdown voltage of avalanche multiplication from\u000026.2 V to 12.6 V. Additionally, we propose avalanche multiplication in MoS2-xOx\u0000as an efficient sensing mechanism to overcome the limitations of gas sensing.\u0000The MoS2-xOx sensors display an ultra-high response to NO2 gas in the air, with\u0000a response of 5.8x103 % to NO2 gas of 50 ppb at room temperature, which is\u0000nearly two orders of magnitude higher than resistance-type gas detectors based\u0000on TMDCs. This work demonstrates that hopping transfer induced by high-density\u0000oxygen defects can effectively decrease the breakdown voltage of MoS2-xOx FETs,\u0000enhancing avalanche multiplication and serving as a promising mechanism for\u0000ultrasensitive gas detection.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"127 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}