{"title":"Investigation of fundamental photonic devices and effect of post-cleaning using potassium hydroxide on lithium niobate chip","authors":"Kiwon Kwon, Heedeuk Shin, Hyeong-soon Jang, Hyungjun Heo, Hojoong Jung","doi":"10.1007/s40042-024-01250-0","DOIUrl":"10.1007/s40042-024-01250-0","url":null,"abstract":"<div><p>This study demonstrates the fabrication and optical characterization of lithium niobate photonic devices including waveguides, beam splitters, and microring resonators on a thin-film lithium niobate platform. Through precise fabrication techniques and KOH post-cleaning following Ar-based etching, we achieved effective optical performance across key parameters such as transmission loss, splitting ratios, and <i>Q</i>-factors. These results show the potential of lithium niobate in advanced photonic applications, paving the way for its use in integrated on-chip photonics.</p></div>","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"86 2","pages":"85 - 90"},"PeriodicalIF":0.8,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994453","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}
{"title":"Fe-doped buffer layer with graded layered AlGaN/GaN HEMT for millimeter-wave radar applications","authors":"A. Akshaykranth, J. Ajayan, Sandip Bhattacharya","doi":"10.1007/s40042-024-01249-7","DOIUrl":"10.1007/s40042-024-01249-7","url":null,"abstract":"<div><p>The low cost and scalability of silicon substrates have led to increasing attention to AlGaN/GaN high-electron-mobility transistors (HEMTs) on silicon wafer. We developed and simulated the GaN-based HEMT on Si wafer using the Silvaco TCAD software. The performance of rectangular-gate AlGaN/GaN HEMT on Si wafer is examined in detail with respect to the effects of channel length variation, barrier thickness variation, and gate length variation. The performance of this HEMT structure with a gate length of 100 nm and optimized channel layer thickness (CT) of 200 nm has shown a significant <i>I</i><sub>DS</sub> of 1.11 A/mm, a substantial <i>G</i><sub>m</sub> of 329.79 mS/mm, an impressive <i>f</i><sub>T</sub> of 199.40 GHz, and a notable output current of 1.71 A/mm. When the barrier layer thickness (BT) was varied from 6 to 10 nm while maintaining a 200 nm channel layer thickness, the performance declined at higher barrier thicknesses, yielding an <i>I</i><sub>DS</sub> of 0.8 A/mm, a <i>G</i><sub>m</sub> of 206 mS/mm, an f<sub>T</sub> of 193.2 GHz, and an output current of 1.26 A/mm. Finally, this HEMT structure demonstrated superior performance with a gate length (LG) of 40 nm, exhibiting a drain current of 1.92 A/mm, a transconductance (<i>G</i><sub>m</sub>) of 465.49 mS/mm, and a cut-off frequency (<i>f</i><sub>T</sub>) of 465 GHz, and output current (<i>I</i><sub>D</sub>) of 2.11 A/mm. The optimized device structure’s high-power performance without compromising RF performance, they are suitable for millimeter-wave radar applications.</p></div>","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"86 2","pages":"120 - 125"},"PeriodicalIF":0.8,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994689","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}
Hyoseong Jang, Seung Kwon Jeon, Seungmin Jeong, Heedae Kim
{"title":"Erratum: Existence of symmetry-broken excited states in single and ensemble quantum ring structures","authors":"Hyoseong Jang, Seung Kwon Jeon, Seungmin Jeong, Heedae Kim","doi":"10.1007/s40042-024-01247-9","DOIUrl":"10.1007/s40042-024-01247-9","url":null,"abstract":"","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"85 12","pages":"1062 - 1062"},"PeriodicalIF":0.8,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142826252","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}
{"title":"smCamera: all-in-one software package for single-molecule data acquisition and data analysis","authors":"Kyung Suk Lee, Taekjip Ha","doi":"10.1007/s40042-024-01243-z","DOIUrl":"10.1007/s40042-024-01243-z","url":null,"abstract":"<div><p>In the last decades, biological applications of single-molecule methods have grown rapidly and researchers with expertise in microscopy and instrumentation have adopted these techniques and advanced them even further. However, practicing single-molecule methods is still challenging for most because of the need for expensive equipments and instrumentation demands as well as complicated data acquisition and analysis workflow consisting of multiple steps using different software in each of them. smCamera is an all-in-one software package which aims to alleviate steep learning curves of the data acquisition and analysis. From recording movies through extraction of time series of single-molecule fluorescence resonance energy transfer (smFRET), everything can be done in a single program without any additional software or programming languages. Although smCamera has not been published before, it has been distributed to facilitate adaption of smFRET experiments and there has been requests for support for this software. We hope that this work answers questions from researchers using smCamera and also provides an opportunity to introduce and distribute smCamera for new users.</p></div>","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"86 1","pages":"1 - 13"},"PeriodicalIF":0.8,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s40042-024-01243-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Muzamil Hussain, Shahzad Maqsood Khan, Muhammad Shafiq, Sami Ullah Khan, Muhammad Rafi Raza, Iskander Tlili
{"title":"ZnO-modified PLA/PBAT composites: a study on mechanical strength and biodegradability for sustainable packaging applications","authors":"Muzamil Hussain, Shahzad Maqsood Khan, Muhammad Shafiq, Sami Ullah Khan, Muhammad Rafi Raza, Iskander Tlili","doi":"10.1007/s40042-024-01244-y","DOIUrl":"10.1007/s40042-024-01244-y","url":null,"abstract":"<div><p>This investigation reflects the enhanced mechanical as well as degradation features of a blend (PLA/30PBAT) containing 70 wt% of polylactic acid (PLA) and 30 wt% of polybutylene adipate terephthalate (PBAT). The ZnO-modified composites of PLA/PBAT (PLA/30PBAT/2ZnO) were prepared by adding the 2 wt% of ZnO into PLA/30PBAT matrix. Adding ZnO into PLA/PBAT improved the tensile properties such as strength and elongation. The PLA/30PBAT/2ZnO composite shows a 26% increment in the tensile strength as compared to PLA/30PBAT and a 91% improvement in elongation at the break over PLA/30PBAT. Further, PLA/30PBAT/2ZnO composites exhibit 31.2% higher degradation than PLA/30PBAT. Overall, the PLA/30PBAT/2ZnO composite demonstrates a balanced combination of improved mechanical performance and moderate degradability.</p></div>","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"86 3","pages":"180 - 188"},"PeriodicalIF":0.8,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108643","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}
Seungmin Chae, Changwon Lee, Yumi Kim, Yeonsang Park, Yunjong Kim, Sungho Lee, Un Jeong Kim
{"title":"Near-infrared antireflection coating operated with broad incident angles","authors":"Seungmin Chae, Changwon Lee, Yumi Kim, Yeonsang Park, Yunjong Kim, Sungho Lee, Un Jeong Kim","doi":"10.1007/s40042-024-01240-2","DOIUrl":"10.1007/s40042-024-01240-2","url":null,"abstract":"<div><p>We designed and demonstrated antireflection coatings that exhibit high transmittance regardless of the angle of light incidence. The suggested design is adapted from a universal impedance matching layer model and is optimized by a particle swarm optimization technique. The thin layers separated from a layer with low refractive index is known to exhibit minimal changes in dielectric constant even when incident angle changes. The simulation results obtained by finite difference time domain method showed that designed structure has transmission with more than 96% at the incidence angle of less than 71° in the range of 700–900 nm wavelength. We fabricated the designed structure and measured transmission at different incidence angles to certify simulation results. By measuring transmittance of fabricated sample while changing an incidence angle from 0° to 80° by 10°, we found out that transmittance is more than 90% within the incidence angle of 70°, and the average of transmission at the wavelength of 800 nm measured within the above incidence angle is calculated as 0.916.</p></div>","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"86 1","pages":"68 - 72"},"PeriodicalIF":0.8,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142939064","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}
{"title":"Zn concentration’s effects on the structure, optical, and photoconductivity properties of ZnxCd1–xS thin films synthesized by chemical spray pyrolysis","authors":"Hersh Ahmed Khizir, Najib Tuma Rassam","doi":"10.1007/s40042-024-01242-0","DOIUrl":"10.1007/s40042-024-01242-0","url":null,"abstract":"<div><p>In this study, the Zn<sub>x</sub>Cd<sub>1-x</sub>S ternary compounds are prepared as thin films on a glass slide substrate at 350 °C using a spray pyrolysis technique. Using X-ray diffraction to examine the films' structure, it was possible to determine that they were polycrystalline. The hexagonal crystal structure of films with <i>x</i> up to 0.4 in Zn<sub><i>x</i></sub>Cd<sub>1–<i>x</i></sub>S has been found to exhibit a preferred orientation of the (101), (002), and (110) planes. A cubic zinc blende structure with a (111) plane preference orientation is observed for <i>x</i> = 0.6 and 0.8. The optical energy gap was found to have increased from 2.45 to 3.52 eV for <i>x</i> = 0 to 1, according to transmittance assessments. The temperature dependence of d.c. electrical conductivity σ, which was found to be semiconducting, was also found to be in the range of 308–373 K. This resulted in an activation energy Ea of 0.26 eV for <i>x</i> = 0 and 0.73 eV for <i>x</i> = 1. Finally, based on the measurement of photoconductivity's intensity dependency, <i>x</i> = 0.6 was determined to be the greatest photosensitivity.</p></div>","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"86 9","pages":"875 - 883"},"PeriodicalIF":0.8,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143896749","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}
Seunghoon Yu, Jinhyeok Park, Yonghwan Jo, Woojong Kim, Hyeonsu Kim, Won-Young Choi, Mingu Kim, Dong-Soo Han, Myung-Hwa Jung, Kungwon Rhie, Kyujoon Lee
{"title":"The control of magnetization reversal by tuning the interlayer exchange interaction in magnetic multilayers","authors":"Seunghoon Yu, Jinhyeok Park, Yonghwan Jo, Woojong Kim, Hyeonsu Kim, Won-Young Choi, Mingu Kim, Dong-Soo Han, Myung-Hwa Jung, Kungwon Rhie, Kyujoon Lee","doi":"10.1007/s40042-024-01238-w","DOIUrl":"10.1007/s40042-024-01238-w","url":null,"abstract":"<div><p>The interest of noncollinear spin structures in magnetic multilayers has recently gained a lot of interest in spintronics due to the observation of unique phenomena in these systems. In magnetic multilayers coupled by the Ruderman–Kittel–Kasuya–Yosida (RKKY) interaction the study of noncollinear interactions has gained interest. In this paper, we study the magnetization reversal of two magnetic layers with different magnetic anisotropy directions coupled by the RKKY interaction. We have chosen Pt/Co/Ru/Co<sub>40</sub>Fe<sub>40</sub>B<sub>20</sub> structures where the Pt/Co show perpendicular-magnetic anisotropy and CoFeB show an in-plane magnetic anisotropy.</p></div>","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"86 1","pages":"62 - 67"},"PeriodicalIF":0.8,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938925","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}
Chanmi Kim, Eun-San Kim, Seong Hee Park, Chong Shik Park, Chang-Ki Min, Woo Jun Byeon
{"title":"Error analysis study for electron linear accelerator optimized using multi-objective genetic algorithm","authors":"Chanmi Kim, Eun-San Kim, Seong Hee Park, Chong Shik Park, Chang-Ki Min, Woo Jun Byeon","doi":"10.1007/s40042-024-01232-2","DOIUrl":"10.1007/s40042-024-01232-2","url":null,"abstract":"<div><p>The injector system of fourth-generation synchrotron radiation accelerators should be optimally designed to produce a good quality beam. In the previous study, we used Multi-Objective Genetic Algorithm (MOGA) to optimize the injector system parameters to meet the beam requirements. To ensure that the injector operation parameters optimized by MOGA fall within practical ranges, we conducted an error analysis. The injector, composed of RF cavities and magnets, includes an analysis of potential errors in RF cavity phase and gradient, as well as magnet strengths across three distinct steps. First, we considered errors that could occur during operation, such as the input phases of RF cavities and the strengths of cavities and magnets. Second, we considered installation errors, including rotation errors of devices. Finally, we simulated scenarios where all errors occurred simultaneously. The simulation results showed that even when errors occurred, the beam quality remained within our acceptable range. Through this error analysis, we confirmed that the linac operation parameters optimized by MOGA are indeed practical and usable.</p></div>","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"86 1","pages":"23 - 30"},"PeriodicalIF":0.8,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938837","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}
{"title":"Effect of isolation strategies on epidemic spreading in multiplex networks with an annealed interactions layer","authors":"Minsuk Kim, Soon-Hyung Yook","doi":"10.1007/s40042-024-01239-9","DOIUrl":"10.1007/s40042-024-01239-9","url":null,"abstract":"<div><p>When an unprecedented infectious disease with high mortality and transmissibility emerges, immediate access to vaccines or medicines is often unavailable. Therefore, many health authorities rely on non-pharmaceutical interventions, such as contact tracing combined with isolation, to mitigate the spread of the disease. However, contact tracing is generally effective only for well-known fixed contacts such as regular contacts of an individual. In contrast, random and anonymous infections, which are difficult to trace, may still occur, potentially leading to large-scale outbreaks especially when the disease is highly transmissible. In this study, we test the efficacy of isolation based on contact tracing among fixed regular contacts even when untraceable random contacts exist as well. We simulate this scenario using the susceptible-infected-recover model on double-layered multiplex networks, where one layer has a fixed structure, while the other layer is time-varying. Our numerical results indicate that tracing the secondary contacts significantly reduces both the final epidemic size and the number of isolations per unit time, even with imperfect traceability. Our findings suggest that the isolation protocol combined with secondary contact tracing can be an effective measure against unprecedented infectious diseases, applicable to a broad range of fixed contact structures.</p></div>","PeriodicalId":677,"journal":{"name":"Journal of the Korean Physical Society","volume":"86 1","pages":"73 - 84"},"PeriodicalIF":0.8,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938838","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}