{"title":"Strain-induced competition of thermoelectric parameters in monolayer HfS2","authors":"Yi-min Ding, Min Jiang, Yu Wu, Youyong Li","doi":"10.1063/5.0287334","DOIUrl":"https://doi.org/10.1063/5.0287334","url":null,"abstract":"Band convergence strategy has been widely used to improve thermoelectric performance. However, the effect of intervalley scattering caused by band convergence on the electrical and thermal properties is usually neglected. In this work, we investigate the thermoelectric properties of monolayer HfS2 under different tensile strains. The valence band of HfS2 can realize convergence at 6% strain. In this case, the Seebeck coefficient S reaches the maximum due to the significant increase in the density of states. Furthermore, the carrier scattering channels increases due to the intervalley scattering, which makes the electrical conductivity σ drop sharply. The competition between Seebeck coefficient and electrical conductivity leads the power factor (S2σ) decreasing with strain. On the other hand, band convergence effectively reduces the lattice thermal conductivity by softening phonons and increasing the phonon scattering rate. Furthermore, it enhances phonon scattering through electron–phonon coupling. The lattice thermal conductivity leads the way in the competition between thermoelectric parameters, resulting in a significant increase in ZT following band convergence. Our work provides important insights into the modulation of thermoelectric performance through strain and band convergence strategy.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"63 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145282926","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}
Kanchan Singh Rana, Navneet Thakur, Swaroop Ganguly, Dipankar Saha
{"title":"Determination of the dependence of long-lived hot-carrier temperature on excitation power and its effect on the radiative decay rate in GaN/InGaN nanodisks","authors":"Kanchan Singh Rana, Navneet Thakur, Swaroop Ganguly, Dipankar Saha","doi":"10.1063/5.0283647","DOIUrl":"https://doi.org/10.1063/5.0283647","url":null,"abstract":"Quantum-confined GaN/InGaN-based heterostructures are a natural choice for light-emitting devices due to their enhanced luminescence and superior efficiency. The reduced density of states and improved quantum confinement lead to improved radiative efficiency. However, under high excitation, quantum-confined structures exhibit band tail filling at elevated energies, giving rise to several effects, including altered carrier capture dynamics, extended radiative lifetimes, hot-carrier accumulation, and phonon bottlenecks. These effects may reduce the efficacy of the radiative process in the active region. Here, we show that the persistence of hot carriers—characterized by their elevated effective temperature and cooling dynamics—serves as a good metric for evaluating the overall efficacy of quantum-confined structures. To demonstrate this, we employ GaN/InGaN nanodisks as the host material and present a methodology for extracting hot-carrier temperature and cooling behavior using power-dependent photoluminescence and time-correlated single-photon counting measurements. While the radiative efficiency is measured around the peak emission wavelength, the short-wavelength tail reveals clear signatures of high-energy carrier occupation in both ground and excited states.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"135 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145282931","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}
Sultan Malik, Felix M. Mayor, Wentao Jiang, Hyunseok Oh, Carl Padgett, Viraj Dharod, Jayameenakshi Venkatraman, Ania C. Bleszynski Jayich, Amir H. Safavi-Naeini
{"title":"Integrated phononic waveguide on thin-film lithium niobate on diamond","authors":"Sultan Malik, Felix M. Mayor, Wentao Jiang, Hyunseok Oh, Carl Padgett, Viraj Dharod, Jayameenakshi Venkatraman, Ania C. Bleszynski Jayich, Amir H. Safavi-Naeini","doi":"10.1063/5.0285138","DOIUrl":"https://doi.org/10.1063/5.0285138","url":null,"abstract":"We demonstrate wavelength-scale phononic waveguides formed by transfer-printed thin-film lithium niobate (LN) on bulk diamond, a material stack that combines the strong piezoelectricity of LN with the high acoustic velocity and color-center compatibility of diamond. We characterize a delay line based on a 100 μm long phononic waveguide at room and cryogenic temperatures. The total insertion loss through the device at 4 K is −5.8 dB, corresponding to a >50 % transducer efficiency, at a frequency of 2.8 GHz. Our work represents a step toward phonon-mediated hybrid quantum systems consisting of strain-sensitive color centers in diamond.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"54 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145282925","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}
Liuyun Yang, Haotian Ye, Jinlin Wang, Ding Wang, Bingxuan An, Tao Wang, Rui Wang, Fang Liu, Bowen Sheng, Weikun Ge, Ping Wang, Xinqiang Wang
{"title":"Molecular beam epitaxy of In-assisted ScAlN/GaN HEMT structures with ultralow sheet resistance","authors":"Liuyun Yang, Haotian Ye, Jinlin Wang, Ding Wang, Bingxuan An, Tao Wang, Rui Wang, Fang Liu, Bowen Sheng, Weikun Ge, Ping Wang, Xinqiang Wang","doi":"10.1063/5.0283382","DOIUrl":"https://doi.org/10.1063/5.0283382","url":null,"abstract":"ScAlN, featuring bipolar switchable spontaneous polarization along with enhanced piezoelectricity and electromechanical coupling coefficients, emerges as a highly promising ultrawide bandgap semiconductor for next-generation high-power and high-frequency electronic applications. In this work, we demonstrate an ultralow sheet resistance two-dimensional electron gas (2DEG) in ScAlN-based high electron mobility transistor (HEMT) structures, grown on sapphire substrates via molecular beam epitaxy. By employing indium (In) as a surfactant and introducing an ultrathin AlN interlayer to engineer a sharp interface, we achieve a sheet resistance of 137 Ω/□, with an electron mobility of 1020 cm2/V·s and a sheet electron density of 4.5 × 1013 cm−2. The realization of ultralow sheet resistance in ScAlN/GaN heterostructures paves the way for advancements in microwave and radio frequency device technologies.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"1 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145282929","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}
Linghui Gong, Chao Cai, Hai Lin, Yidan Zhang, Zhaoyu Wang, Zequan Xu, Yubin Liu
{"title":"Quantitative photoacoustic tomography of blood oxygenation enhanced by Monte Carlo modeling","authors":"Linghui Gong, Chao Cai, Hai Lin, Yidan Zhang, Zhaoyu Wang, Zequan Xu, Yubin Liu","doi":"10.1063/5.0299956","DOIUrl":"https://doi.org/10.1063/5.0299956","url":null,"abstract":"We present a Monte Carlo-enhanced photoacoustic tomography (MC-PAT) system for quantitative three-dimensional mapping of tissue optical properties and blood oxygenation. Combining Monte Carlo light transport with finite-element acoustic inversion, the system achieved accurate absorption coefficient quantification (0.44 ± 0.02 mm−1, 1.85% deviation) and high spatial resolution (250 μm). In vivo pilot studies (n = 3) demonstrated reliable measurements (0.42 ± 0.02 mm−1, 2.78% deviation) and clear arteriovenous differentiation (arterial: 97.8 ± 0.8% sO2; venous: 74.5 ± 1.3% sO2) with 0.8% error vs pulse oximetry. MC-PAT shows potential for functional vascular studies and future clinical translation.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"119 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145282932","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}
D. Bafia, B. Abdisatarov, R. Pilipenko, Y. Lu, G. Eremeev, A. Romanenko, A. Grassellino
{"title":"Quantifying trapped magnetic vortex losses in niobium resonators at mK temperatures","authors":"D. Bafia, B. Abdisatarov, R. Pilipenko, Y. Lu, G. Eremeev, A. Romanenko, A. Grassellino","doi":"10.1063/5.0282159","DOIUrl":"https://doi.org/10.1063/5.0282159","url":null,"abstract":"Trapped magnetic vortices in niobium introduce microwave losses that degrade the performance of superconducting resonators. While such losses have been extensively studied above 1 K, we report here their direct quantification in the millikelvin and low-photon regime relevant to quantum devices. Using a high-quality factor 3D niobium cavity cooled through its superconducting transition in controlled magnetic fields, we isolate vortex-induced losses and find the resistive component of the sensitivity to trapped flux S to be approximately 2 n Ω/mG at 10 mK and 6 GHz. The decay rate is initially dominated by two-level system (TLS) losses from the native niobium pentoxide, with vortex-induced degradation of T1 occurring above Btrap∼ 50 mG. In the absence of the oxide, even 10 mG of trapped flux limits performance, Q0∼ 1010, or T1∼ 350 ms, underscoring the need for stringent magnetic shielding. The resistive sensitivity, S, decreases with temperature and remains largely field-independent, whereas the reactive component, S′, exhibits a maximum near 0.8 K. These behaviors are well modeled within the Coffey–Clem framework in the zero-creep limit, under the assumption that vortex pinning is enhanced by thermally activated processes. Our results suggest that niobium-based transmon qubits can tolerate vortex-induced dissipation at trapped field levels up to several hundred mG, but achieving long coherence times still requires careful magnetic shielding to suppress lower-field losses from other mechanisms.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"18 1 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145282936","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}
{"title":"Liquid collector-assisted electrohydrodynamic printing of unrestricted-height architectures","authors":"Jiyao Xing, Xiaobo Wen, Sansan Yan, Nannan Xu, Zhongmin Geng, Dongming Xing","doi":"10.1063/5.0275172","DOIUrl":"https://doi.org/10.1063/5.0275172","url":null,"abstract":"Despite numerous efforts, electrohydrodynamic direct-writing still faces a significant challenge in constructing 3D architectures with considerable height. Herein, we present a liquid collector-assisted electrohydrodynamic (LCE) printing strategy to print architectures with unrestricted height. This method employs a liquid bath with an immersed descending platform instead of the traditional solid collector, enabling the ink to solidify at the liquid surface through solvent exchange while keeping the as-printed architectures always submerged in the liquid. Both theoretical analysis and experimental investigation reveal that optimizing the Z axis movement speed, based on the single-layer printing path length, printing speed, and flow rate, is pivotal to the execution of LCE printing. We demonstrate that LCE printing can continuously fabricate a honeycomb architecture until it reaches the depth limit of the currently used liquid bath, achieving a height-to-wall thickness ratio up to 1314, with a height of 67 mm and a wall thickness of 51 μm. The results indicate that LCE printing thoroughly addresses the limitation of printable height, making it a highly versatile, high-resolution 3D printing technique with potential applications in smart materials, energy devices, and biomedical engineering.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"64 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145282922","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}
Yichen Su, Chenyan Hu, Feng Pan, Jilei Chen, Cheng Song
{"title":"Enhancement of magnon transport length in easy-plane antiferromagnets","authors":"Yichen Su, Chenyan Hu, Feng Pan, Jilei Chen, Cheng Song","doi":"10.1063/5.0274061","DOIUrl":"https://doi.org/10.1063/5.0274061","url":null,"abstract":"Long-distance magnon transport in antiferromagnets is crucial for developing future magnon-based devices with high speed, density, and stability. However, the magnon decay length remains limited in easy-plane antiferromagnets due to the mismatch between injected magnon modes and eigen magnon modes, as well as the resulting dephasing process. Here, we improved the magnon decay length in easy-plane antiferromagnetic α-Fe2O3 (0001) single crystal by utilizing coherent magnons as carriers. The polarization and phase of coherent magnons maintain the single state during transport, effectively eliminating the dephasing effect. At room temperature, coherent magnons exhibit a magnon decay length of 3 μm, substantially longer than the 320 nm observed for incoherent magnons. Notably, the incoherent magnon transport displays temperature independence approaching the Morin temperature, highlighting the fundamental limitations of incoherent magnons. Our findings demonstrate the advantages of coherent magnons and suggest a promising pathway for long-distance magnon transport in easy-plane antiferromagnets.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"86 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145260761","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}
Yong Li, Fushan Wang, Junyao Yin, Hao Tang, Juekuan Yang
{"title":"Remarkable thermal hysteresis of thermal conductivity in nearly freestanding VO2 nanowire across the phase transition","authors":"Yong Li, Fushan Wang, Junyao Yin, Hao Tang, Juekuan Yang","doi":"10.1063/5.0286216","DOIUrl":"https://doi.org/10.1063/5.0286216","url":null,"abstract":"The thermal conductivity of a nearly freestanding VO2 nanowire was measured in the vicinity of phase transition temperature using thermal bridge method. It was discovered that the thermal conductivity measured during cooling can be significantly greater than during heating in the temperature range of 315–355 K. The pronounced hysteresis results from a large phase transition temperature range during cooling as confirmed by optical imaging and Raman studies. However, this behavior was absent in clamped VO2 nanowires, suggesting that even small thermal stress can change the thermal behavior of VO2 nanowires during phase transition.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"6 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145260789","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}
{"title":"Superconducting spintronic device based on Fe3GaTe2/CsV3Sb5/Fe3GaTe2 van der Waals heterojunctions","authors":"Jing Kong, Heshuang Wei, Jinyu Duan, Yuanyu Song, Gaomeng Hou, Pengfei Liu, Ping Wang, Delin Zhang, Yong Jiang","doi":"10.1063/5.0272896","DOIUrl":"https://doi.org/10.1063/5.0272896","url":null,"abstract":"van der Waals (vdW) heterojunctions have emerged as highly promising candidates for next-generation spintronic devices, owing to their exceptional interface quality, scalability, and tunable electronic properties. Here, we report a vdW superconducting heterojunction based on the Fe3GaTe2/CsV3Sb5/Fe3GaTe2, which combines the strong perpendicular magnetic anisotropy of Fe3GaTe2 with the superconductivity and charge density wave order of the Kagome metal CsV3Sb5. Notably, this superconducting heterojunction exhibits a magnetoresistance of 0.25% at 2 K, approximately two times higher than that observed at elevated temperatures. The magnetic proximity effect in CsV3Sb5 modulates superconductivity by suppressing spin-singlet Cooper pairing and enabling spin-triplet states. The interplay between magnetism and superconductivity not only elucidates the coexistence of competing electronic orders in CsV3Sb5 but also highlights the potential of such heterojunctions for energy-efficient, high-performance spintronic devices. Our work establishes Fe3GaTe2/CsV3Sb5/Fe3GaTe2 as a promising platform for engineering spin-polarized superconducting states and advancing quantum computing technologies.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"18 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145260722","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}