物理与天体物理最新文献

{"title":"Quality assurance for online adaptive radiotherapy: a secondary dose verification model with geometry-encoded U-Net.","authors":"Shunyu Yan, Austen Maniscalco, Biling Wang, Dan Nguyen, Steve Jiang, Chenyang Shen","doi":"10.1088/2632-2153/ad829e","DOIUrl":"https://doi.org/10.1088/2632-2153/ad829e","url":null,"abstract":"<p><p>In online adaptive radiotherapy (ART), quick computation-based secondary dose verification is crucial for ensuring the quality of ART plans while the patient is positioned on the treatment couch. However, traditional dose verification algorithms are generally time-consuming, reducing the efficiency of ART workflow. This study aims to develop an ultra-fast deep-learning (DL) based secondary dose verification algorithm to accurately estimate dose distributions using computed tomography (CT) and fluence maps (FMs). We integrated FMs into the CT image domain by explicitly resolving the geometry of treatment delivery. For each gantry angle, an FM was constructed based on the optimized multi-leaf collimator apertures and corresponding monitoring units. To effectively encode treatment beam configuration, the constructed FMs were back-projected to <math><mrow><mn>30</mn></mrow> </math> cm away from the isocenter with respect to the exact geometry of the treatment machines. Then, a 3D U-Net was utilized to take the integrated CT and FM volume as input to estimate dose. Training and validation were performed on <math><mrow><mn>381</mn></mrow> </math> prostate cancer cases, with an additional <math><mrow><mn>40</mn></mrow> </math> testing cases for independent evaluation of model performance. The proposed model can estimate dose in ∼ <math><mrow><mn>15</mn></mrow> </math> ms for each patient. The average <i>γ</i> passing rate ( <math><mrow><mn>3</mn> <mi>%</mi> <mrow><mo>/</mo></mrow> <mn>2</mn> <mstyle></mstyle> <mrow><mtext>mm</mtext></mrow> </mrow> </math> , <math><mrow><mn>10</mn> <mi>%</mi></mrow> </math> threshold) for the estimated dose was 99.9% ± 0.15% on testing patients. The mean dose differences for the planning target volume and organs at risk were <math><mrow><mn>0.07</mn> <mi>%</mi> <mo>±</mo> <mn>0.34</mn> <mi>%</mi></mrow> </math> and <math><mrow><mn>0.48</mn> <mi>%</mi> <mo>±</mo> <mn>0.72</mn> <mi>%</mi></mrow> </math> , respectively. We have developed a geometry-resolved DL framework for accurate dose estimation and demonstrated its potential in real-time online ART doses verification.</p>","PeriodicalId":6,"journal":{"name":"ACS Applied Nano Materials","volume":"5 4","pages":"045013"},"PeriodicalIF":6.3,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11467776/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142476443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly Reversible Tuning of Light-Matter Interactions in Van der Waals Materials Coupled with Hydrogel-Assisted Optical Cavity","authors":"Lanxin Xu, Jiaqi Wang, Zishun Li, Peng Xie, Qi Ding, Minghao An, Yingjie Zhao, Yiheng Tang, Lan Li, Chengchen Guo, Wei Wang, Xiaorui Zheng","doi":"10.1002/lpor.202401263","DOIUrl":"https://doi.org/10.1002/lpor.202401263","url":null,"abstract":"Controlling light-matter interactions via cavity systems manifested by Rabi splitting is paramount important for nanophotonics. However, achieving conveniently accessible and active tuning of light-matter interactions remains a formidable challenge. Traditional approaches often necessitate either sophisticated design or meticulous nanofabrication to address this issue. Here, a handy strategy is experimentally demonstrated to build an adjustable coupling system featuring reversibly modulated responses based on dielectric-hydrogel-metal resonators. By controlling the top tungsten disulfide layer thickness, the flexible manipulation of weak-intermediate-strong transitions in exciton-cavity interactions is revealed on a large-scale hydrogel membrane without nanopositioning or lithography. Crucially, by leveraging the inflation sensitivity of the hydrogel, the coupling strength can be reversibly tailored with excellent reproducibility by modulating the resonator's dry/immersed states. The combined merits of captivating design and daily stimulus render the novel hydrogel-based nanocavities as a groundbreaking step toward the development of active and practical integrated optical devices, such as polariton lasing, switches, and sensors.","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"227 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Coupling Single Molecules to DNA-Based Optical Antennas with Position and Orientation Control","authors":"Aleksandra K. Adamczyk, Fangjia Zhu, Daniel Schäfer, Yuya Kanehira, Sergio Kogikoski, Jr., Ilko Bald, Sebastian Schlücker, Karol Kołątaj, Fernando D. Stefani, Guillermo P. Acuna","doi":"10.1021/acsphotonics.4c01506","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c01506","url":null,"abstract":"Optical antennas have been extensively employed to manipulate the photophysical properties of single-photon emitters. Coupling between an emitter and a given resonant mode of an optical antenna depends mainly on three parameters: spectral overlap, relative distance, and relative orientation between the emitter’s transition dipole moment and the antenna. While the first two have already been extensively demonstrated, achieving full coupling control remains unexplored due to the challenges in manipulating at the same time both the position and orientation of single molecules. Here, we use the DNA origami technique to assemble a dimer optical antenna and position a single fluorescent molecule at the antenna gap with controlled orientation, predominately parallel or perpendicular to the antenna’s main axis. We study the coupling for both conditions through fluorescence measurements correlated with scanning electron microscopy images, revealing a 5-fold higher average fluorescence intensity when the emitter is aligned with the antenna’s main axis and a maximum fluorescence enhancement of ∼1400-fold. A comparison to realistic numerical simulations suggests that the observed distribution of fluorescence enhancement arises from small variations in the emitter orientation and gap size. This work establishes DNA origami as a versatile platform to fully control the coupling between emitters and optical antennas, trailblazing the way for self-assembled nanophotonic devices with optimized and more homogeneous performance.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"64 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Ultracompact Polarization-Insensitive 1 × N Silicon-Based Optical Wavelength-Selective Switch by Leveraging I/O Waveguide Spacing Difference","authors":"Zhuping Fan, Xiongshuo Yan, Zhenyu Li, Xiao Ma, Tingting Lang, Dihai Dai, Xuyang Wang, Jun Zou","doi":"10.1021/acsphotonics.4c01606","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c01606","url":null,"abstract":"Wavelength-selective switches (WSS) have large potential applications in future high-capacity, low-latency, flexible, and energy-efficient data center optical networks. Here, a novel ultracompact 1 × <i>N</i> polarization-insensitive WSS is proposed on the silicon-on-insulator (SOI) platform. The WSS comprises one input port with a polarizing beam splitter and rotator (PBSR), two identical (<i>M</i> × <i>N</i> + 1) × (<i>M</i> + <i>N</i>) arrayed waveguide gratings (AWGs) cascaded with <i>M</i> 1 × <i>N</i> thermo-optic (TO) switches, and <i>N</i> output ports with polarization combiners. The AWG works as both a demultiplexer and multiplexer to eliminate the center wavelength mismatch induced by fabrication errors and to achieve an ultracompact footprint. The TO switches placed on loopback arms allow for the routing of each wavelength to any one of the <i>N</i> output ports. A new design of leveraging the I/O waveguide spacing difference between the loopback inputs and demultiplexing outputs of AWG is employed to eliminate waveguide crossings in a conventional WSS layout design. In experiment, a 12-channel 400 GHz spacing 1 × 2 WSS with a footprint of 1.67 × 1.7 mm² is demonstrated. The minimal on-chip loss of 6.8 dB, best extinction ratio of 25 dB, and switching speed of 42 μs are achieved. The measured polarization-dependent loss is &lt;0.5 dB and polarization-dependent wavelength shift is &lt;0.08 nm.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"106 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Numerical model of N-level cascade systems for atomic Radio Frequency sensing applications","authors":"Liam W. Bussey,&nbsp;Yogeshwar B. Kale,&nbsp;Samuel Winter,&nbsp;Fraser A. Burton,&nbsp;Yu-Hung Lien,&nbsp;Kai Bongs,&nbsp;Costas Constantinou","doi":"10.1140/epjqt/s40507-024-00291-5","DOIUrl":"10.1140/epjqt/s40507-024-00291-5","url":null,"abstract":"<div><p>A ready-to-use numerical model has been developed for the atomic ladder (cascade) systems which are widely exploited in Rydberg Radio Frequency (RF) sensors. The model has been explicitly designed for user convenience and to be extensible to arbitrary N-level non-thermal systems. The versatility and adaptability of the model is validated up to 4-level atomic systems by direct comparison with experimental results from the prior art. The numerical model provides a good approximation to the experimental results and provides experimentalists with a convenient ready-to-use model to optimise the operation of an N-level Rydberg RF sensor. Current sensors exploit the 4-level atomic systems based on alkali metal atoms which require visible frequency lasers and these can be expensive and also suffer from high attenuation within optical fiber. The ability to quickly and simply explore more complex N-level systems offers the potential to use cheaper and lower-loss near-infrared lasers.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"11 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-024-00291-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Nanoring Tamm cavity in the telecommunications O band","authors":"Huili Hou, David Dlaka, Jon Pugh, Ruth Oulton, Edmund Harbord","doi":"10.1063/5.0213200","DOIUrl":"https://doi.org/10.1063/5.0213200","url":null,"abstract":"Quantum and classical telecommunications require efficient sources of light. Semiconductor sources, owing to the high refractive index of the medium, often exploit photonic cavities to enhance the external emission of photons into a well-defined optical mode. Optical Tamm States (OTSs) in which light is confined between a distributed Bragg reflector and a thin metal layer have attracted interest as confined Tamm structures are readily manufactureable broadband cavities. Their efficiency is limited however by the absorption inherent in the metal layer. We propose a nanoring Tamm structure in which a nanoscale patterned annular metasurface is exploited to reduce this absorption and thereby enhance emission efficiency. To this end, we present designs for a nanoring Tamm structure optimized for the telecommunications O band and demonstrate a near doubling of output efficiency (35%) over an analogous solid disk confined Tamm structure (18%). Simulations of designs optimized for different wavelengths are suggestive of annular coupling between the Tamm state and surface plasmons. These designs are applicable to the design of single photon sources, nano-LEDs, and nanolasers for communications.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"29 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670400","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":"Artificial mechano-nociceptive system based on transparent ITO/AlN/ITO memristor nociceptor neuron","authors":"Caiyang Ye, Yimeng Xu, Ziyi Dai, Zede Zhu, Chao Li, Kai Qian","doi":"10.1063/5.0235758","DOIUrl":"https://doi.org/10.1063/5.0235758","url":null,"abstract":"Artificial nociceptors demonstrate significant potential in emerging fields such as intelligent prosthetics, humanoid robotics, and electronic skin, capable of transducing external noxious stimuli to the central nervous system. Unlike common sensory neurons, nociceptors exhibit unique characteristics, including “no adaptation,” “relaxation,” “threshold firing,” and “sensitization of allodynia/hyperalgesia.” This study presents a forming-free volatile transparent ITO/AlN/ITO memristor that emulates biological nociceptor behaviors. Leveraging this artificial nociceptor, an artificial mechano-nociceptive system is developed by integrating the ITO/AlN/ITO memristor into a piezoelectric force sensor system for pain sensing and noxious stimuli warning. This research contributes to the advancement of human cognitive capability emulation and artificial intelligence systems, particularly in the domain of pain perception and response.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"32 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665454","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":"Pulsed N2 plasma surface treatment for AlGaN/GaN HEMTs prior to PECVD SiNx passivation to reduce plasma damage","authors":"Kaiyu Wang, Ke Wei, Ruizhe Zhang, Sheng Zhang, Jiaqi Guo, Xiaoqiang He, Jianchao Wang, Sen Huang, Yingkui Zheng, Xiaojuan Chen, Xinhua Wang, Xinyu Liu","doi":"10.1063/5.0235740","DOIUrl":"https://doi.org/10.1063/5.0235740","url":null,"abstract":"In this work, a pulse-mode N2 plasma surface treatment process was proposed as a means of reducing plasma damage and improving the GaN/GaOx ratio on the surface before SiNx deposition, which further contributes to an enhanced density of 2DEG and a reduced sheet resistance. With the pulsed N2 plasma surface treatment combined with subsequent SiNx passivation, the fabricated GaN HEMTs exhibit negligible current collapse and suppressed leakage current. The improved behavior is attributed to the fact that the pulsed N2 plasma is capable of nitriding the surface and removing carbon contaminants as identified through x-ray photoelectron spectroscopy and energy dispersive x-ray spectroscopy. Compared to the traditional continuous-wave-mode N2 plasma, the pulsed N2 plasma pre-treatment effectively prevents continuous collisions of the plasma during acceleration, thereby significantly reducing plasma damage. This work offers valuable insights for surface treatment processes in micro- and nanofabrication.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"8 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665458","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":"Sodium carbonates on Ryugu as evidence of highly saline water in the outer Solar System","authors":"Toru Matsumoto, Takaaki Noguchi, Akira Miyake, Yohei Igami, Megumi Matsumoto, Toru Yada, Masayuki Uesugi, Masahiro Yasutake, Kentaro Uesugi, Akihisa Takeuchi, Hayato Yuzawa, Takuji Ohigashi, Tohru Araki","doi":"10.1038/s41550-024-02418-1","DOIUrl":"https://doi.org/10.1038/s41550-024-02418-1","url":null,"abstract":"<p>Water activity recorded in asteroids offers a perspective on their habitability. Aqueous alteration, namely the interaction of liquid water with minerals, occurred in the parent body of the C-type asteroid Ryugu. However, Ryugu is not a wet body, and the processes that led to the loss of liquid water along with its chemical environment remain unclear. We report the presence of sodium carbonates, chlorides and sulfates in Ryugu samples, which indicate that alkaline, salt-rich water once flowed through its parent body. Highly concentrated brine probably formed through evaporation or freezing of the liquid water in the final stages of aqueous alteration. Similar processes may have occurred in carbonaceous asteroids in the Solar System, although terrestrial weathering of meteorites might obscure evidence of salt precipitation. Sodium salts could be crucial for comparing the evolved water in carbonaceous bodies and alkaline subsurface oceans in the dwarf planet Ceres and the moons of Jupiter and Saturn.</p>","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"49 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Reducing measurement costs by recycling the Hessian in adaptive variational quantum algorithms","authors":"Mafalda Ramôa, Luis Paulo Santos, Nicholas J Mayhall, Edwin Barnes and Sophia E Economou","doi":"10.1088/2058-9565/ad904e","DOIUrl":"https://doi.org/10.1088/2058-9565/ad904e","url":null,"abstract":"Adaptive protocols enable the construction of more efficient state preparation circuits in variational quantum algorithms (VQAs) by utilizing data obtained from the quantum processor during the execution of the algorithm. This idea originated with Adaptive Derivative-Assembled Problem-Tailored variational quantum eigensolver (ADAPT-VQE), an algorithm that iteratively grows the state preparation circuit operator by operator, with each new operator accompanied by a new variational parameter, and where all parameters acquired thus far are optimized in each iteration. In ADAPT-VQE and other adaptive VQAs that followed it, it has been shown that initializing parameters to their optimal values from the previous iteration speeds up convergence and avoids shallow local traps in the parameter landscape. However, no other data from the optimization performed at one iteration is carried over to the next. In this work, we propose an improved quasi-Newton optimization protocol specifically tailored to adaptive VQAs. The distinctive feature in our proposal is that approximate second derivatives of the cost function are recycled across iterations in addition to optimal parameter values. We implement a quasi-Newton optimizer where an approximation to the inverse Hessian matrix is continuously built and grown across the iterations of an adaptive VQA. The resulting algorithm has the flavor of a continuous optimization where the dimension of the search space is augmented when the gradient norm falls below a given threshold. We show that this inter-optimization exchange of second-order information leads the approximate Hessian in the state of the optimizer to be consistently closer to the exact Hessian. As a result, our method achieves a superlinear convergence rate even in situations where the typical implementation of a quasi-Newton optimizer converges only linearly. Our protocol decreases the measurement costs in implementing adaptive VQAs on quantum hardware as well as the runtime of their classical simulation.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"80 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670338","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}