M. Schmidbauer, J. Maltitz, F. Stümpel, M. Hanke, C. Richter, J. Schwarzkopf, J. Martin
{"title":"Periodic lateral superlattice in bonded SrTiO3/SrTiO3 twisted perovskites","authors":"M. Schmidbauer, J. Maltitz, F. Stümpel, M. Hanke, C. Richter, J. Schwarzkopf, J. Martin","doi":"10.1063/5.0251478","DOIUrl":"https://doi.org/10.1063/5.0251478","url":null,"abstract":"Stacking of freestanding membranes enables the formation of interfaces beyond what can be obtained with classical heteroepitaxy. In particular, twisted interfaces provide unique physical properties not existent in the corresponding individual layers. An ideal twist grain boundary yields an in-plane screw-dislocation network, assuming sufficiently strong interactions across the interface, for example, via covalent or ionic bonding. Hereby, the distance between dislocation lines, that is the length scale of the Moiré pattern, is set by the twist angle between the adjacent crystalline surfaces and the lattice mismatch in case that different materials are placed together. The associated strain gradients of the periodic pattern are especially appealing for oxide-based perovskites due to the intricate connection between surface polarization and subtle structural deformations such as the oxygen octahedra tilt. Recently, freestanding oxide perovskites became available via the sacrificial layer approach, opening a pathway toward oxide-based Moiré materials. Here, we demonstrate efficient bonding of a freestanding SrTiO3 layer to a SrTiO3 single-crystal by initially conducting a wafer-bonding process at high temperature and only subsequently dissolving the sacrificial layer. We investigate the twisted SrTiO3/SrTiO3 interface with x-ray diffraction in grazing incidence geometry and observe clear signatures of a highly periodic lateral superlattice consistent with the formation of a screw-dislocation network. Our work demonstrates a robust route for the fabrication of twisted perovskites and their development into a functional material platform with designed strain gradients at the nanoscale.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"14 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143582438","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":"Proximity-induced antisymmetric humps in Hall resistivity in Fe-doped monolayer WSe2","authors":"Mengqi Fang, Chunli Tang, Siwei Chen, Zitao Tang, Min-Yeong Choi, Jae Hyuck Jang, Hee-Suk Chung, Maya Narayanan Nair, Wencan Jin, Eui-Hyeok Yang","doi":"10.1063/5.0250741","DOIUrl":"https://doi.org/10.1063/5.0250741","url":null,"abstract":"Non-collinear spin texture has attracted great attention since it provides an important probe of the interaction between electron and topological spin textures. While it has been widely reported in chiral magnets, oxide heterostructures, and hybrid systems such as ferromagnet/heavy metal and ferromagnet/topological insulators, the study of non-collinear spin texture in two-dimensional (2D) van der Waals (vdW) dilute magnetic semiconductor (DMS) monolayers is relatively lacking, hindering the understanding at the atomically thin scale. Here, we probe the temperature-dependent antisymmetric humps in Hall resistivity by utilizing the proximity coupling of Fe-doped monolayer WSe2 (Fe:WSe2) synthesized using chemical vapor deposition on a Pt Hall bar. Multiple characterization methods were employed to demonstrate that Fe atoms substitutionally replace W atoms, making a 2D vdW DMS at room temperature. Distinct from the intrinsic anomalous Hall effect, we found the transverse Hall resistivity of Fe:WSe2 displaying two additional antisymmetric peak features in the temperature-dependent measurements. These peaks are attributed to the magnetic features at the Fe:WSe2 and Pt interface. Our work shows that a DMS synthesized from 2D vdW transition metal dichalcogenides is promising for realizing magnetic and spintronic applications.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"19 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143582439","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}
Jongmug Kang, Seongbin Park, Hye Ryeon Park, Seungbin Lee, Jin-Hyun Kim, Minjong Lee, Dushyant M. Narayan, Jeong Gyu Yoo, Geon Park, Harrison Sejoon Kim, Yong Chan Jung, Rino Choi, Jiyoung Kim, Si Joon Kim
{"title":"Thermal budget study to simultaneously achieve low-temperature (<400 °C) process and high endurance of ferroelectric Hf0.5Zr0.5O2 thin films","authors":"Jongmug Kang, Seongbin Park, Hye Ryeon Park, Seungbin Lee, Jin-Hyun Kim, Minjong Lee, Dushyant M. Narayan, Jeong Gyu Yoo, Geon Park, Harrison Sejoon Kim, Yong Chan Jung, Rino Choi, Jiyoung Kim, Si Joon Kim","doi":"10.1063/5.0256712","DOIUrl":"https://doi.org/10.1063/5.0256712","url":null,"abstract":"This work comprehensively investigates the thermal budget required to simultaneously achieve low-temperature process conditions and high endurance in atomic layer deposited ferroelectric Hf0.5Zr0.5O2 (HZO) thin films. Because a certain level of thermal budget is required to achieve ferroelectricity in 10 nm HZO thin films, the crystallization temperature can be lowered below 400 °C by simply increasing the annealing time. In addition, the analysis of the crystallization behavior of HZO thin films based on the Johnson–Mehl–Avrami–Kolmogorov model revealed that longer annealing times are required to lower the annealing temperature for HZO crystallization due to the limitation of the crystallization rate. Consequently, low-temperature (&lt;400 °C) ferroelectric HZO thin films with large remanent polarization along with improved leakage behavior and endurance were realized. These results not only facilitate the back-end-of-line integration of HZO thin films but also demonstrate the feasibility of in situ HZO crystallization by thermal budget for subsequent interconnect formation, simplifying the overall process and saving costs by eliminating a dedicated annealing process.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"28 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143582436","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":"On-demand storing time-bin qubit states with optical quantum memory","authors":"Ming-Shuo Sun, Chun-Hui Zhang, Yi-Zhen Luo, Shuang Wang, Yun Liu, Jian Li, Qin Wang","doi":"10.1063/5.0255199","DOIUrl":"https://doi.org/10.1063/5.0255199","url":null,"abstract":"Quantum memory, serving as a crucial device for storing and releasing quantum states, holds significant importance in long-distance quantum communications. To date, quantum memories have been realized in many different systems. However, most of them have complex structures and high cost. Besides, it is not easy to simultaneously achieve both high storage efficiency and fidelity. In this paper, we experimentally demonstrate a low-cost optical quantum memory with high efficiency and high fidelity, by utilizing a butterfly-shaped cavity consisting of one polarization beam splitter, two reflecting mirrors, and one pockels cell crystal. In order to quantify the quality of the quantum memory, we carry out tomography measurements on the time-bin qubits encoded with weak coherent states after storage for N rounds. The storage efficiency per round can reach up to 95.0%, and the overall state fidelity can exceed 99.1%. It thus seems very promising for practical implementation in quantum communication and networks.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"207 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143590048","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}
Yu Yan, Bo Liu, Xianyang Lu, Junlin Wang, Sarnjeet S. Dhesi, Iain G. Will, Vlado K. Lazarov, Jun Du, Jing Wu, Rong Zhang, Yongbing Xu
{"title":"The origin of the uniaxial magnetic anisotropy in Fe/GaAs(100) system","authors":"Yu Yan, Bo Liu, Xianyang Lu, Junlin Wang, Sarnjeet S. Dhesi, Iain G. Will, Vlado K. Lazarov, Jun Du, Jing Wu, Rong Zhang, Yongbing Xu","doi":"10.1063/5.0253345","DOIUrl":"https://doi.org/10.1063/5.0253345","url":null,"abstract":"Fe/GaAs is a prototype system of spin injection at room temperature. The interfacial strain and oriented bonds are both considered the origin of the Fe in-plane uniaxial magnetic anisotropy (UMA), which remains decisive. Here, by the x-ray magnetic circular dichroism (XMCD) and the vibrating sample magnetometer measurements, this study shows that in the Fe/Cr(t)/GaAs structure, the in-plane UMA of Fe originates from the chemical bonding between the Fe and the GaAs substrate by varying Cr thickness, t. The UMA drops as the Cr coverage increases, characterized by a decrease in the saturation field from 2400 to 57 Oe. The XMCD studies reveal that the Fe orbital moment, a signature of chemical bonds, decreases from 0.216 μB at Cr = 0 ML to 0.138 μB at Cr = 5 ML. The reduction of the Fe orbital moment and the UMA are qualitatively consistent, establishing a link between the UMA and the interfacial chemical bonds. The decreased UMA remains unchanged at t &gt; 5 ML, above which Fe and GaAs are fully separated by a continuous Cr layer. Our findings provide clear experimental evidence that the UMA in the Fe/GaAs system originates from the oriented interface bonds, clarifying the UMA origin in this prototype system.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"193 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143575327","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}
Zhenxing Fang, Haipeng Xie, Yuhuan Xiao, Zihao Wang, Xianjun Cheng, Tao Xu, Han Huang, Conghua Zhou
{"title":"Depth-sensitive atomic ratio between iodine/lead and nitrogen/lead in lead halide perovskite film during octylammonium iodide-based surface modification","authors":"Zhenxing Fang, Haipeng Xie, Yuhuan Xiao, Zihao Wang, Xianjun Cheng, Tao Xu, Han Huang, Conghua Zhou","doi":"10.1063/5.0246864","DOIUrl":"https://doi.org/10.1063/5.0246864","url":null,"abstract":"Atomic ratios of iodine/lead (I/Pb) and nitrogen/lead (N/Pb) are carefully examined during octylammonium iodide (OAI) based surface modification on lead halide perovskite (PVSK). X-ray photoemission spectroscopy (XPS) study showed that modification at moderate concentration (20 mM modification) increases the “I/Pb” ratio from 2.08 to 2.72. Angle-resolved XPS study is performed by varying the takeoff angle from 150° to 90°. OAI treatment increases the I/Pb ratio at each takeoff angle, showing the coordination of Pb (II) has been fully improved. Besides, the atomic ratio between N2 (from OAI) and Pb (from PVSK) decreases from 1.13 to 0.86 (20 mM modification), showing that OAI prefers to react with the surface layer of PVSK. Due to the improved coordination environment of Pb (II), the work function of PVSK increases by approximately 0.3 eV as revealed by Kelvin probe force microscopy study, the built-in potential of perovskite solar cell (PSC) increases from 1.0 to 1.05 V. Accordingly, carrier extraction is accelerated, while carrier lifetime is prolonged, and the power conversion efficiency of PSCs is upgraded from 20.47% to 24.00%, with the fill factor rising from 77.32% to 82.79% and the open-circuit voltage from 1.11 to 1.16 V. The study helps understand the close relationship between two-dimensional (2D) precursor molecule modification and coordination behavior of Pb (II) in PVSK.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"18 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143575352","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}
Hexiang Zhang, Xuguang Zhang, Fangqi Chen, Mauro Antezza, Yi Zheng
{"title":"Flexible tuning of asymmetric near-field radiative thermal transistor by utilizing distinct phase-change materials","authors":"Hexiang Zhang, Xuguang Zhang, Fangqi Chen, Mauro Antezza, Yi Zheng","doi":"10.1063/5.0256162","DOIUrl":"https://doi.org/10.1063/5.0256162","url":null,"abstract":"Phase-change materials (PCMs) play a pivotal role in the development of advanced thermal devices due to their reversible phase transitions, which drastically modify their thermal and optical properties. In this study, we present an effective dynamic thermal transistor with an asymmetric design that employs distinct PCMs, vanadium dioxide (VO2), and germanium antimony telluride (GST), on either side of the gate terminal, which is the center of the control unit of the near-field thermal transistor. This asymmetry introduces unique thermal modulation capabilities, taking control of thermal radiation in the near-field regime. VO2 transitions from an insulating to a metallic state, while GST undergoes a reversible switch between amorphous and crystalline phases, each inducing substantial changes in thermal transport properties. By strategically combining these materials, the transistor exhibits enhanced functionality, dynamically switching between states of absorbing and releasing heat by tuning the temperature of gate. This gate terminal not only enables active and efficient thermal management but also provides effective opportunities for manipulating heat flow in radiative thermal circuits. Our findings highlight the potential of such asymmetrically structured thermal transistors in advancing applications across microelectronics, high-speed data processing, and sustainable energy systems, where precise and responsive thermal control is critical for performance and efficiency.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"17 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143569745","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":"Alternative contacting strategy for correlated perovskite nickelates: From the overlooked perspective of the metallic work functions","authors":"Ziang Li, Jingxin Gao, Hao Zhang, Chen Liu, Xiaoguang Xu, Wei Mao, Jing Zhao, Kangkang Meng, Yong Wu, Yong Jiang, Nuofu Chen, Jikun Chen","doi":"10.1063/5.0252692","DOIUrl":"https://doi.org/10.1063/5.0252692","url":null,"abstract":"While the multiple electronic phase transitions in rare-earth perovskite nickelates (ReNiO3) open up a new paradigm in developing the next-generation logical devices and sensors catering for artificial intelligence, their respective contact strategy for making electronic devices largely relies on noble metal (e.g., Pt). Herein, we demonstrate the critical roles associated with the work function (W) of the contacting metal that is critical in the device application of ReNiO3 based on both their conventional metal-to-insulator transition (MIT) and the recently discovered hydrogen-triggered Mottronic transition. Owing to the high valence Ni3+ associated with ReNiO3 that is rather oxidative and also results in bi-polar carriers from generating Ligand holes, we demonstrate that their low resistive contact is only achievable for using inert metal (e.g., the standard electrode potential beyond 0.4 V) with either high W (e.g., &gt;5 eV) or low W (e.g., &lt;4.7 eV). This sheds light on alternative contacting strategies for ReNiO3 using the much cheaper Cu or Ag with low W that can also achieve abrupt resistive switch across MIT, in addition to the present noble metal with high W. Furthermore, the magnitude of W was also discovered to dominate the hydrogen-triggered Mottronic transition for ReNiO3 via upward (or downward) bending the energy bands that promotes (or inhibits) the H+ inward diffusion that switches the orbital configurations between the electron itinerant Ni3+ and electron localized Ni2+. Clarifying these previously overlooked roles from the perspective of the metallic contacts further paves the way for the correlated electronic applications of ReNiO3.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"58 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143569750","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":"Rapid growth kinetics of β-Fe3Ge2 intermetallic compound within undercooled liquid Fe–Ge alloys","authors":"N. S. Hou, D. L. Geng, G. Y. Zhu, B. Wei","doi":"10.1063/5.0253749","DOIUrl":"https://doi.org/10.1063/5.0253749","url":null,"abstract":"The rapid dendrite growth of the β-Fe3Ge2 intermetallic compound within two liquid Fe–Ge alloys was investigated using the bulk undercooling technique. The liquid undercooling was achieved up to 202 K (0.14TL) and 227 K (0.16TL) for hypereutectic Fe70Ge30 and Fe67Ge33 alloys, respectively, where the primary β-Fe3Ge2 phase always exhibited non-faceted growth characteristics. Within the Fe70Ge30 alloy, the β-Fe3Ge2 phase morphology transformed from columnar to equiaxed dendrites with increasing undercooling, where the maximum growth velocity was measured as 1.44 m/s at 141 K undercooling. Beyond this undercooling threshold, the (β-Fe3Ge2 + α1-Fe17Ge3) anomalous eutectic grew directly from the undercooled liquid, which may be attributed to the remarkably enhanced nucleation rate of the α1-Fe17Ge3 phase. For the Fe67Ge33 alloy, the primary β-Fe3Ge2 dendrites achieved a high growth velocity of 3.53 m/s at the maximum 227 K undercooling. Furthermore, the Vickers hardness of the β-Fe3Ge2 compound in these two alloys was improved significantly, which resulted mainly from microstructure refinement.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"14 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143569756","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}
Jie Zhou, Daniel Vincent, Sudip Acharya, Solomon Ojo, Yang Liu, Yifu Guo, Alireza Abrand, Jiarui Gong, Dong Liu, Samuel Haessly, Jianping Shen, Shining Xu, Yiran Li, Yi Lu, Hryhorii Stanchu, Luke Mawst, Parsian K. Mohseni, Kai Sun, Zetian Mi, Zhenqiang Ma, Shui-Qing Yu
{"title":"Grafted AlGaAs/GeSn optical pumping laser operating up to 130 K","authors":"Jie Zhou, Daniel Vincent, Sudip Acharya, Solomon Ojo, Yang Liu, Yifu Guo, Alireza Abrand, Jiarui Gong, Dong Liu, Samuel Haessly, Jianping Shen, Shining Xu, Yiran Li, Yi Lu, Hryhorii Stanchu, Luke Mawst, Parsian K. Mohseni, Kai Sun, Zetian Mi, Zhenqiang Ma, Shui-Qing Yu","doi":"10.1063/5.0241572","DOIUrl":"https://doi.org/10.1063/5.0241572","url":null,"abstract":"Group IV GeSn double-heterostructure (DHS) lasers offer unique advantages of a direct bandgap and CMOS compatibility. However, further improvements in the laser performance have been bottlenecked by the limited junction properties of GeSn through conventional epitaxy and wafer bonding. This work leverages semiconductor grafting to synthesize and characterize optically pumped ridge edge-emitting lasers with an AlGaAs nanomembrane transfer-printed onto an epitaxially grown GeSn substrate, interfaced by an ultrathin Al2O3 layer. The uniform formation of this nanometer-thin ALD-Al2O3 interlayer and structural integrity of the grafted heterojunction are confirmed in STEM. The grafted AlGaAs/GeSn DHS lasers show a lasing threshold of 11.06 mW at 77 K and a maximum lasing temperature of 130 K. These results highlight the potential of the grafting technique for enhancing charge carrier and optical field confinements, paving the way for room-temperature electrically injected GeSn lasers.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"67 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570292","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}