Applied Physics Letters最新文献_第4页

Dead-zone-free single-beam atomic magnetometer based on free-induction-decay of Rb atoms 基于铷原子自由感应衰变的无死区单束原子磁强计

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2025-01-28 DOI: 10.1063/5.0248330

Shrey Mehta, G. K. Samanta, Raghwinder Singh Grewal

{"title":"Dead-zone-free single-beam atomic magnetometer based on free-induction-decay of Rb atoms","authors":"Shrey Mehta, G. K. Samanta, Raghwinder Singh Grewal","doi":"10.1063/5.0248330","DOIUrl":"https://doi.org/10.1063/5.0248330","url":null,"abstract":"Free-induction-decay (FID) magnetometers have evolved as simple magnetic sensors for sensitive detection of unknown magnetic fields. However, these magnetometers suffer from a fundamental problem known as a “dead zone,” making them insensitive to certain magnetic field directions. Here, we demonstrate a simple experimental scheme for the dead-zone-free operation of a FID atomic magnetometer. Using a single laser beam containing equal strength of linear- and circular-polarization components and amplitude modulation at a low-duty cycle, we have synchronously pumped the rubidium (87Rb) atoms with both first- and second-order frequency harmonics. Such a pumping scheme has enabled us to observe the free Larmor precession of atomic spins at a frequency of ΩL (orientation) and/or 2ΩL (alignment) in a single FID signal, depending on the direction of the external magnetic field. We observed that the amplitude of the FID signal does not go to zero for any magnetic field direction, proving the absence of dead zones in the magnetometer. The magnetometer has a sensitivity in the range of 3.2–8.4 pT/Hz in all directions. Our experimental scheme can be crucial in developing miniaturized atomic magnetometers for various practical applications, including geomagnetic applications.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"115 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143055337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

引用次数: 0

Quantitative analysis of leakage current in III-nitride micro-light-emitting diodes

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2025-01-28 DOI: 10.1063/5.0250282

Matthew S. Wong, Tanay Tak, Andrea Y. Ni, Kent Nitta, Srinivas Gandrothula, JaeKwon Kim, NamGoo Cha, Umesh K. Mishra, James S. Speck, Steven P. DenBaars

{"title":"Quantitative analysis of leakage current in III-nitride micro-light-emitting diodes","authors":"Matthew S. Wong, Tanay Tak, Andrea Y. Ni, Kent Nitta, Srinivas Gandrothula, JaeKwon Kim, NamGoo Cha, Umesh K. Mishra, James S. Speck, Steven P. DenBaars","doi":"10.1063/5.0250282","DOIUrl":"https://doi.org/10.1063/5.0250282","url":null,"abstract":"The electrical characteristics under forward- and reverse-bias conditions of III-nitride blue and green micro-light-emitting diodes (μLEDs) are analyzed. A fitting model is proposed to determine the contributions of reverse leakage current and the effectiveness of sidewall treatments. Moreover, the forward-bias currents of the μLEDs are examined using the extracted ideality factor to examine the impacts of sidewall defects. The results show that sidewall treatments are highly effective for suppression of leakage currents. From the efficiency perspective, higher wall-plug efficiency (WPE) than external quantum efficiency (EQE) is observed when the operating voltage is lower than the photon voltage in both blue and green 20 × 20 μm2 devices. This enhancement of the WPE over the EQE is due to the suppression of Shockley–Read–Hall (SRH) nonradiative recombination. These observations indicate that μLEDs with sidewall treatments not only improve optical performance but also further enhance the electrical performance of devices by suppressing the leakage current paths due to SRH nonradiative recombination processes.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"59 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143055321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

引用次数: 0

Electrochemical reduction for modulating spin state of nickel: A pathway to improved water and seawater oxidation

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2025-01-28 DOI: 10.1063/5.0250893

Yu Shuai, Shucheng Liu, Tao Zhang, Yi Liu

{"title":"Electrochemical reduction for modulating spin state of nickel: A pathway to improved water and seawater oxidation","authors":"Yu Shuai, Shucheng Liu, Tao Zhang, Yi Liu","doi":"10.1063/5.0250893","DOIUrl":"https://doi.org/10.1063/5.0250893","url":null,"abstract":"Understanding the electronic structure of catalysts is crucial for analyzing electrocatalyst behavior. Here, we present a straightforward method to modify the electronic configuration of active sites in nickel-iron-niobium layered double hydroxides (NiFeNb-LDHs) via electrochemical reduction (ER), uncovering key factors that enhance oxygen evolution reaction (OER) activity. The results indicate that ER-NiFeNb-LDHs display excellent OER performance and long-term stability over 60 h in various electrolytes (271.99 mV@50 mA cm−2 in 1M KOH and 280.56 mV@50 mA cm−2 in 1M KOH +0.5M NaCl). Furthermore, the cell voltage of the two-electrode electrolyzer ER-NiFeNb-LDHs ǁ Pt/C achieves a current density of 50 mA cm−2 at an ultra-low voltage of 1.58 V, significantly outperforming the commercial RuO2ǁPt/C. X-ray absorption spectroscopy, magnetic characterization, and density functional theory calculations reveal that the unsaturated coordination environment created by ER modifies the electronic state distribution between eg and t2g orbitals, effectively lowering the spin state of nickel and enhancing its OER activity.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"53 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143055334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

引用次数: 0

Wavelength-insensitive and fast photothermoelectric response in magnetic-Weyl-semimetal Co3Sn2S2 crystals

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2025-01-28 DOI: 10.1063/5.0245833

Hong-Tao Jiang, Cheng-Hao Yin, Lin Cao, Qi-Xun Wen, Su-Tao Sun, Jian Zhou, Shu-Hua Yao, Yang-Yang Lv, Y. B. Chen, Yan-Feng Chen

{"title":"Wavelength-insensitive and fast photothermoelectric response in magnetic-Weyl-semimetal Co3Sn2S2 crystals","authors":"Hong-Tao Jiang, Cheng-Hao Yin, Lin Cao, Qi-Xun Wen, Su-Tao Sun, Jian Zhou, Shu-Hua Yao, Yang-Yang Lv, Y. B. Chen, Yan-Feng Chen","doi":"10.1063/5.0245833","DOIUrl":"https://doi.org/10.1063/5.0245833","url":null,"abstract":"We systematically characterize the photothermoelectric (PTE) effect of pristine and Se-doped (4%, 8%, and 11%) Co3Sn2S2 crystals, a magnetic-Weyl-semimetal, on electromagnetic-wave wavelength and temperature. The photovoltages of these Co3Sn2S2 crystals are insensitive to the electromagnetic-wave wavelength, with 23% variance, in bands ranging from 444 to 1550 nm. Remarkably, the 4%-Se doped Co3Sn2S2 demonstrates the best PTE performance among these samples, yielding a 22.4 mV/W optical responsivity and a short response time (∼100 ms) under 1550 nm illumination. The photovoltage of Co3Sn2S2 nearly monotonically increased with increasing temperature. The theoretical analyses verify that the wavelength-insensitive PTE response of Co3Sn2S2 comes from the nearly same trend of its wavelength-dependent optical refractive index and extinction coefficient, and the best PTE performance of 4%-Se doped Co3Sn2S2 is attributed to the largest product of Seebeck coefficient and electrical conductivity. This work demonstrates that magnetic Weyl semimetals may be promising for infrared photodetection.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"10 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143055335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

引用次数: 0

Low-temperature buffer layer-assisted heteroepitaxial growth of γ-CuI thin films by pulsed laser deposition: Tailoring electrical properties

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2025-01-28 DOI: 10.1063/5.0250124

Yang Chen, Michael S. Bar, Susanne Selle, Daniel Splith, Michael Lorenz, Marius Grundmann, Holger von Wenckstern

引用次数: 0

Toward model-free temperature diagnostics of warm dense matter from multiple scattering angles

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2025-01-28 DOI: 10.1063/5.0248230

H. M. Bellenbaum, B. Bachmann, D. Kraus, Th. Gawne, M. P. Böhme, T. Döppner, L. B. Fletcher, M. J. MacDonald, Zh. A. Moldabekov, T. R. Preston, J. Vorberger, T. Dornheim

引用次数: 0

Temporal uniaxial crystal in a dispersion-modulated lattice model 弥散调制晶格模型中的时间单轴晶体

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2025-01-28 DOI: 10.1063/5.0243052

Meng-Cheng Jin, Ze-Guo Chen, Ming-Hui Lu, Peng Zhan, Yan-Feng Chen

引用次数: 0

Towards higher electro-optic response in AlScN

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2025-01-27 DOI: 10.1063/5.0244434

Haochen Wang, Sai Mu, Chris G. Van de Walle

引用次数: 0

Enhanced breakdown strength and reduced polarization hysteresis in relaxor ferroelectric polymers with increased gamma phase content for energy storage capacitors 提高γ相含量的弛豫铁电聚合物的击穿强度并减少极化滞后，用于储能电容器

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2025-01-27 DOI: 10.1063/5.0246289

Renfan Lin, Shuangwu Huang, Weiping Gong, Qiyan Zhang, Q. M. Zhang

{"title":"Enhanced breakdown strength and reduced polarization hysteresis in relaxor ferroelectric polymers with increased gamma phase content for energy storage capacitors","authors":"Renfan Lin, Shuangwu Huang, Weiping Gong, Qiyan Zhang, Q. M. Zhang","doi":"10.1063/5.0246289","DOIUrl":"https://doi.org/10.1063/5.0246289","url":null,"abstract":"Polymer dielectric energy storage capacitors play a vital role in modern electronic and electrical power systems, particularly in high-voltage environments. However, achieving both high energy density and charge–discharge efficiency presents a significant challenge for next-generation applications that demand miniaturization and compact design. In this study, we present relaxor ferroelectric terpolymers with an increased gamma (γ)-phase content, prepared through a facile and scalable interfacial engineering approach that incorporates ultra-low amounts of graphene oxide. The γ-phase crystals in the terpolymer reduce hysteresis losses and generate numerous deep traps, resulting in enhanced performance. These terpolymers achieve a high energy density of up to 15.2 J/cm3 and an improved breakdown strength of 562 MV/m, representing enhancements of 62% and 39.8%, respectively, compared to the pristine terpolymer. The results suggest that tuning the phase structure of relaxor ferroelectric terpolymers offers a pathway to developing ferroelectric polymers with enhanced energy density and charge–discharge efficiency for energy storage capacitors.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"62 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143050664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

引用次数: 0

Nonradiative quenching of EPR signals in germanium-doped AlGaN: Evidence for DX-center formation 掺锗氮化铝中 EPR 信号的非辐射淬灭：DX 中心形成的证据

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2025-01-27 DOI: 10.1063/5.0249701

Jason Forbus, Darshana Wickramaratne, John L. Lyons, M. E. Zvanut

引用次数: 0