Pub Date : 2026-05-01Epub Date: 2025-09-26DOI: 10.1109/tasc.2025.3614571
Jintao Hu, Junseong Kim, Liangjun Shao, Juan Bascuñán, Yukikazu Iwasa, Jerome L Ackerman, Dongkeun Park
In this paper, we present the design and test results of a low-AC-loss Nb3Sn model coil developed to validate key enabling technologies for a fast-switching-field magnetic resonance imaging (MRI) magnet concept that can change the magnetic field very quickly in time, within 1 second, between significantly different field strengths: a high field (3 T) for relaxometry and prepolarization and a low field (0.5 T) for spectroscopy and imaging. While conventional MRI magnets require a static magnetic field, we expect that our proposed superconducting magnet with rapidly changing fields can provide opportunities for novel contrast mechanisms, which include level-crossing between spin-1/2 and quadrupolar nuclei, accelerated spin-lattice relaxation, and adiabatic demagnetization/remagnetization, by permitting differential relaxometry enabled by a large field strength difference, and ratiometric molecular/superthermal imaging. We have developed and demonstrated an innovative magnet design that uses a very low-AC-loss Nb3Sn coil and a novel cooling technology featuring highly heat-conductive thermal links between the coil and solid nitrogen surrounding the coil. These thermal links in solid nitrogen are anchored at one end to the cryocooler cold head. This design enables rapid switching between two magnetic fields in the superconducting magnet without inducing quench. The paper provides details on the construction, test results, and an analysis of the maximum temperature rise in the coil of the small-scale fast-switching-field magnet system.
{"title":"Low-AC-Loss Nb3Sn Validation Model Coil in Solid Nitrogen for a Fast-Switching-Field MRI Magnet Prototype.","authors":"Jintao Hu, Junseong Kim, Liangjun Shao, Juan Bascuñán, Yukikazu Iwasa, Jerome L Ackerman, Dongkeun Park","doi":"10.1109/tasc.2025.3614571","DOIUrl":"10.1109/tasc.2025.3614571","url":null,"abstract":"<p><p>In this paper, we present the design and test results of a low-AC-loss Nb3Sn model coil developed to validate key enabling technologies for a fast-switching-field magnetic resonance imaging (MRI) magnet concept that can change the magnetic field very quickly in time, within 1 second, between significantly different field strengths: a high field (3 T) for relaxometry and prepolarization and a low field (0.5 T) for spectroscopy and imaging. While conventional MRI magnets require a static magnetic field, we expect that our proposed superconducting magnet with rapidly changing fields can provide opportunities for novel contrast mechanisms, which include level-crossing between spin-1/2 and quadrupolar nuclei, accelerated spin-lattice relaxation, and adiabatic demagnetization/remagnetization, by permitting differential relaxometry enabled by a large field strength difference, and ratiometric molecular/superthermal imaging. We have developed and demonstrated an innovative magnet design that uses a very low-AC-loss Nb3Sn coil and a novel cooling technology featuring highly heat-conductive thermal links between the coil and solid nitrogen surrounding the coil. These thermal links in solid nitrogen are anchored at one end to the cryocooler cold head. This design enables rapid switching between two magnetic fields in the superconducting magnet without inducing quench. The paper provides details on the construction, test results, and an analysis of the maximum temperature rise in the coil of the small-scale fast-switching-field magnet system.</p>","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"36 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12577748/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145431246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2026-05-01Epub Date: 2025-10-09DOI: 10.1109/tasc.2025.3619470
Anbo Wu, Justin Ricci, Minfeng Xu, Vijay Soni, Gene Conte, Chris Van Epps, Michael Parizh, Wolfgang Stautner, Yihe Hua, Seung-Kyun Lee, Mark Vermilyea, Desmond Tb Yeo, Thomas Kf Foo
A compact 7.0 T MRI system (C7T) has been successfully constructed, cooled down, and ramped (energized) to 7.01 T at GE HealthCare Technology and Innovation Center. The C7T magnet is designed for a B0-field homogeneity of <1.0 ppm over a 26-cm field-of-view, dedicated for MRI brain imaging. The C7T magnet applies a fully closed-loop cryogenic cooling system which condenses only 12 liters of liquid helium at 4.2 K from high pressure helium gas charged at room temperature. The helium is permanently sealed inside the cooling system even after a quench. This newly developed 7.0 T MRI has similar size and stray magnetic field as a clinical whole-body 3.0 T MRI magnet, it can be easily installed in a 3T scanner bay. This C7T MRI system can greatly improve the access to high performance 7T brain imaging for more patients. The cooldown, ramp and quench protection performance of the compact 7T MRI magnet prototype is reported in this paper.
在GE医疗保健技术和创新中心，一个紧凑的7.0 T MRI系统（C7T）已成功构建、冷却并提升（通电）到7.01 T。C7T磁体设计用于b0场均匀性
{"title":"Cooldown and Ramp Test of a Low-Cryogen, Lightweight, Head-Only 7T MRI Magnet.","authors":"Anbo Wu, Justin Ricci, Minfeng Xu, Vijay Soni, Gene Conte, Chris Van Epps, Michael Parizh, Wolfgang Stautner, Yihe Hua, Seung-Kyun Lee, Mark Vermilyea, Desmond Tb Yeo, Thomas Kf Foo","doi":"10.1109/tasc.2025.3619470","DOIUrl":"10.1109/tasc.2025.3619470","url":null,"abstract":"<p><p>A compact 7.0 T MRI system (C7T) has been successfully constructed, cooled down, and ramped (energized) to 7.01 T at GE HealthCare Technology and Innovation Center. The C7T magnet is designed for a B0-field homogeneity of <1.0 ppm over a 26-cm field-of-view, dedicated for MRI brain imaging. The C7T magnet applies a fully closed-loop cryogenic cooling system which condenses only 12 liters of liquid helium at 4.2 K from high pressure helium gas charged at room temperature. The helium is permanently sealed inside the cooling system even after a quench. This newly developed 7.0 T MRI has similar size and stray magnetic field as a clinical whole-body 3.0 T MRI magnet, it can be easily installed in a 3T scanner bay. This C7T MRI system can greatly improve the access to high performance 7T brain imaging for more patients. The cooldown, ramp and quench protection performance of the compact 7T MRI magnet prototype is reported in this paper.</p>","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"36 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12829978/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146051826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2026-02-09DOI: 10.1177/15311074261417883
Connor J Ballard, Louisa J Preston, Lewis R Dartnell, Eva Mateo-Marti, Catherine Regan, Andrew Coates
The alteration of martian deposits under extreme surface conditions remains a key challenge for their mineral-organic interpretation and paleoenvironmental reconstruction. This study investigates the spectral detection and alteration of mineral-organic signatures in Lake Salda hydromagnesite microbialites under martian sublimation and radiation (UV) conditions. Samples were analyzed using visible near-infrared and Fourier transform infrared (FTIR) spectroscopy, then sublimated via lyophilization and exposed to UV radiation in the Planetary Atmospheres and Surfaces Simulation Chamber. Sublimation reduced the intensity of water and carbonate vibrations and enhanced CH2 ν3 and PO2- ν3 organic features; this demonstrated that interstitial water sublimation may reduce O-H spectral noise, improve organic visibility, and reveal volatile sublimation patterns for future Mars rovers, such as Rosalind Franklin. In a three-sol (74 h) simulation of martian UV radiation (200-400 nm) under 7 mbar of CO2, FTIR spectral intensity was reduced, and organic CH2 ν3 and PO2- features were significantly degraded. These findings reveal spectral alterations under martian surface conditions and highlight organic biosignature vulnerability at equatorial latitudes, informing preservation protocols for future missions.
{"title":"Biosignature Detection and Preservation in Lake Salda Microbialites Under Simulated Martian Conditions.","authors":"Connor J Ballard, Louisa J Preston, Lewis R Dartnell, Eva Mateo-Marti, Catherine Regan, Andrew Coates","doi":"10.1177/15311074261417883","DOIUrl":"https://doi.org/10.1177/15311074261417883","url":null,"abstract":"<p><p>The alteration of martian deposits under extreme surface conditions remains a key challenge for their mineral-organic interpretation and paleoenvironmental reconstruction. This study investigates the spectral detection and alteration of mineral-organic signatures in Lake Salda hydromagnesite microbialites under martian sublimation and radiation (UV) conditions. Samples were analyzed using visible near-infrared and Fourier transform infrared (FTIR) spectroscopy, then sublimated via lyophilization and exposed to UV radiation in the Planetary Atmospheres and Surfaces Simulation Chamber. Sublimation reduced the intensity of water and carbonate vibrations and enhanced CH<sub>2</sub> ν<sub>3</sub> and PO<sub>2</sub><sup>-</sup> ν<sub>3</sub> organic features; this demonstrated that interstitial water sublimation may reduce O-H spectral noise, improve organic visibility, and reveal volatile sublimation patterns for future Mars rovers, such as Rosalind Franklin. In a three-sol (74 h) simulation of martian UV radiation (200-400 nm) under 7 mbar of CO<sub>2</sub>, FTIR spectral intensity was reduced, and organic CH<sub>2</sub> ν<sub>3</sub> and PO<sub>2</sub><sup>-</sup> features were significantly degraded. These findings reveal spectral alterations under martian surface conditions and highlight organic biosignature vulnerability at equatorial latitudes, informing preservation protocols for future missions.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"15311074261417883"},"PeriodicalIF":2.6,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146140981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2026-02-09DOI: 10.1021/acsphotonics.5c03087
Chengwei Song,Yiming Wang,Yunyun Ji,Peng Shen,Shiqiang Zhao,Liang Ma,Xianghui Wang,Shengjiang Chang,Fei Fan
Terahertz trace sensing is inherently constrained by weak light-matter interactions. To address this fundamental bottleneck, we propose a novel sensing paradigm based on surface plasmonic (SP) field interference, transitioning from conventional free-space spectroscopic sensing to on-chip surface optical field sensing. Leveraging the extraordinary confinement and focusing capabilities of SP fields, the localized light intensity is substantially enhanced, thereby enhancing the efficiency of light-matter interactions. More importantly, by employing orthogonal slit antenna pairs as coherent surface wavelet sources and a three-stage coherent superposition mechanism, two sets of focused surface waves construct an interferometric field with precisely tunable optical path differences. Ultrasensitive detection is realized through the analysis of focal interference spectra. Experimental validation based on the hydrolysis of acetylcholinesterase demonstrates that the sensing platform attains a detection limit (LOD) as low as 3.125 μg/mL. Furthermore, by fusing 2D surface spectral data with machine-learning algorithms, accurate prediction of enzyme concentrations in the range of 3.125–50 μg/mL is successfully achieved. This work establishes an on-chip precision interferometric sensing technique integrating photonic integration technology and data fusion, representing a breakthrough advancement in the on-chip integration level, detection accuracy, and operational robustness of terahertz sensing systems.
{"title":"On-Chip Terahertz Interferometric Sensing Based on Focused Surface Plasmonic Field and Spatial Spectral Fusion Methodology","authors":"Chengwei Song,Yiming Wang,Yunyun Ji,Peng Shen,Shiqiang Zhao,Liang Ma,Xianghui Wang,Shengjiang Chang,Fei Fan","doi":"10.1021/acsphotonics.5c03087","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c03087","url":null,"abstract":"Terahertz trace sensing is inherently constrained by weak light-matter interactions. To address this fundamental bottleneck, we propose a novel sensing paradigm based on surface plasmonic (SP) field interference, transitioning from conventional free-space spectroscopic sensing to on-chip surface optical field sensing. Leveraging the extraordinary confinement and focusing capabilities of SP fields, the localized light intensity is substantially enhanced, thereby enhancing the efficiency of light-matter interactions. More importantly, by employing orthogonal slit antenna pairs as coherent surface wavelet sources and a three-stage coherent superposition mechanism, two sets of focused surface waves construct an interferometric field with precisely tunable optical path differences. Ultrasensitive detection is realized through the analysis of focal interference spectra. Experimental validation based on the hydrolysis of acetylcholinesterase demonstrates that the sensing platform attains a detection limit (LOD) as low as 3.125 μg/mL. Furthermore, by fusing 2D surface spectral data with machine-learning algorithms, accurate prediction of enzyme concentrations in the range of 3.125–50 μg/mL is successfully achieved. This work establishes an on-chip precision interferometric sensing technique integrating photonic integration technology and data fusion, representing a breakthrough advancement in the on-chip integration level, detection accuracy, and operational robustness of terahertz sensing systems.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"132 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138829","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}
Pub Date : 2026-02-09DOI: 10.1021/acsphotonics.5c02402
Yiang Sun,Yuxing Li,Zhengda Dong,Hao Ge,Zhongmin Huang,Chuanxiang Sheng,Haibin Zhao,Jie Gu,Jun Wang
Monolayer tungsten disulfide (WS2) is a promising candidate for exploring exciton and trion physics thanks to its strong light-matter interactions and large exciton binding energy at room temperature (RT). Trions, in particular, offer intriguing prospects for optoelectronic and valleytronic applications. However, trion stability at RT and a low excitation density are limited by the inherently low free-electron concentration in monolayer WS2. Here we demonstrate a robust approach to enhance trion emission by constructing a type-II heterostructure between monolayer WS2 and the CsPbBr3 perovskite. Through band engineering, we achieve efficient n-doping of WS2 by electron transfer from CsPbBr3, facilitating a pronounced enhancement of trion emission at RT. Under low-power excitation, trions dominate the photoluminescence (PL) spectra. Time-resolved PL measurements reveal distinct lifetimes of excitons and trions in WS2, perovskites, and heterostructures, confirming the charge-transfer dynamics. Helicity-resolved PL spectra show that trions preserve valley polarization in heterostructures. By integrating this heterostructure into an optical microcavity, we further amplify trion emission via the Purcell effect. Our findings present a viable strategy for achieving stable RT trion emission, advancing the development of transition metal dichalcogenide-perovskite hybrid systems for optoelectronic applications.
{"title":"Room-Temperature Trion Emission Enhancement in Monolayer WS2/CsPbBr3 Perovskite Heterostructures","authors":"Yiang Sun,Yuxing Li,Zhengda Dong,Hao Ge,Zhongmin Huang,Chuanxiang Sheng,Haibin Zhao,Jie Gu,Jun Wang","doi":"10.1021/acsphotonics.5c02402","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c02402","url":null,"abstract":"Monolayer tungsten disulfide (WS2) is a promising candidate for exploring exciton and trion physics thanks to its strong light-matter interactions and large exciton binding energy at room temperature (RT). Trions, in particular, offer intriguing prospects for optoelectronic and valleytronic applications. However, trion stability at RT and a low excitation density are limited by the inherently low free-electron concentration in monolayer WS2. Here we demonstrate a robust approach to enhance trion emission by constructing a type-II heterostructure between monolayer WS2 and the CsPbBr3 perovskite. Through band engineering, we achieve efficient n-doping of WS2 by electron transfer from CsPbBr3, facilitating a pronounced enhancement of trion emission at RT. Under low-power excitation, trions dominate the photoluminescence (PL) spectra. Time-resolved PL measurements reveal distinct lifetimes of excitons and trions in WS2, perovskites, and heterostructures, confirming the charge-transfer dynamics. Helicity-resolved PL spectra show that trions preserve valley polarization in heterostructures. By integrating this heterostructure into an optical microcavity, we further amplify trion emission via the Purcell effect. Our findings present a viable strategy for achieving stable RT trion emission, advancing the development of transition metal dichalcogenide-perovskite hybrid systems for optoelectronic applications.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"24 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138828","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}
Pub Date : 2026-02-09DOI: 10.22331/q-2026-02-09-1999
Yiyuan Chen, Jonas Helsen, Maris Ozols
The Sachdev–Ye–Kitaev (SYK) model is a prominent model of strongly interacting fermions that serves as a toy model of quantum gravity and black hole physics. In this work, we study the Trotter error and gate complexity of the quantum simulation of the SYK model using Lie–Trotter–Suzuki formulas. Building on recent results by Chen and Brandão [6] — in particular their uniform smoothing technique for random matrix polynomials — we derive bounds on the first- and higher-order Trotter error of the SYK model, and subsequently find near-optimal gate complexities for simulating these models using Lie–Trotter–Suzuki formulas. For the $k$-local SYK model on $n$ Majorana fermions, at time $t$, our gate complexity estimates for the first-order Lie–Trotter–Suzuki formula scales with $tilde{mathcal{O}}(n^{k+frac{5}{2}}t^2)$ for even $k$ and $tilde{mathcal{O}}(n^{k+3}t^2)$ for odd $k$, and the gate complexity of simulations using higher-order formulas scales with $tilde{mathcal{O}}(n^{k+frac{1}{2}}t)$ for even $k$ and $tilde{mathcal{O}}(n^{k+1}t)$ for odd $k$. Given that the SYK model has $Theta(n^k)$ terms, these estimates are close to optimal. These gate complexities can be further improved upon in the context of simulating the time evolution of an arbitrary fixed input state $|psirangle$, leading to a $mathcal{O}(n^2)$-reduction in gate complexity for first-order formulas and $mathcal{O}(sqrt{n})$-reduction for higher-order formulas.
We also apply our techniques to the sparse SYK model, which is a simplified variant of the SYK model obtained by deleting all but a $Theta(n)$ fraction of the terms in a uniformly i.i.d. manner. We find the average (over the random term removal) gate complexity for simulating this model using higher-order formulas scales with $tilde{mathcal{O}}(n^{1+frac{1}{2}} t)$ for even $k$ and $tilde{mathcal{O}}(n^{2} t)$ for odd $k$. Similar to the full SYK model, we obtain a $mathcal{O}(sqrt{n})$-reduction simulating the time evolution of an arbitrary fixed input state $|psirangle$.
Our results highlight the potential of Lie–Trotter–Suzuki formulas for efficiently simulating the SYK and sparse SYK models, and our analytical methods can be naturally extended to other Gaussian random Hamiltonians.
{"title":"Trotter error and gate complexity of the SYK and sparse SYK models","authors":"Yiyuan Chen, Jonas Helsen, Maris Ozols","doi":"10.22331/q-2026-02-09-1999","DOIUrl":"https://doi.org/10.22331/q-2026-02-09-1999","url":null,"abstract":"The Sachdev–Ye–Kitaev (SYK) model is a prominent model of strongly interacting fermions that serves as a toy model of quantum gravity and black hole physics. In this work, we study the Trotter error and gate complexity of the quantum simulation of the SYK model using Lie–Trotter–Suzuki formulas. Building on recent results by Chen and Brandão [6] — in particular their uniform smoothing technique for random matrix polynomials — we derive bounds on the first- and higher-order Trotter error of the SYK model, and subsequently find near-optimal gate complexities for simulating these models using Lie–Trotter–Suzuki formulas. For the $k$-local SYK model on $n$ Majorana fermions, at time $t$, our gate complexity estimates for the first-order Lie–Trotter–Suzuki formula scales with $tilde{mathcal{O}}(n^{k+frac{5}{2}}t^2)$ for even $k$ and $tilde{mathcal{O}}(n^{k+3}t^2)$ for odd $k$, and the gate complexity of simulations using higher-order formulas scales with $tilde{mathcal{O}}(n^{k+frac{1}{2}}t)$ for even $k$ and $tilde{mathcal{O}}(n^{k+1}t)$ for odd $k$. Given that the SYK model has $Theta(n^k)$ terms, these estimates are close to optimal. These gate complexities can be further improved upon in the context of simulating the time evolution of an arbitrary fixed input state $|psirangle$, leading to a $mathcal{O}(n^2)$-reduction in gate complexity for first-order formulas and $mathcal{O}(sqrt{n})$-reduction for higher-order formulas.<br/>\u0000<br/> We also apply our techniques to the sparse SYK model, which is a simplified variant of the SYK model obtained by deleting all but a $Theta(n)$ fraction of the terms in a uniformly i.i.d. manner. We find the average (over the random term removal) gate complexity for simulating this model using higher-order formulas scales with $tilde{mathcal{O}}(n^{1+frac{1}{2}} t)$ for even $k$ and $tilde{mathcal{O}}(n^{2} t)$ for odd $k$. Similar to the full SYK model, we obtain a $mathcal{O}(sqrt{n})$-reduction simulating the time evolution of an arbitrary fixed input state $|psirangle$.<br/>\u0000<br/> Our results highlight the potential of Lie–Trotter–Suzuki formulas for efficiently simulating the SYK and sparse SYK models, and our analytical methods can be naturally extended to other Gaussian random Hamiltonians.","PeriodicalId":20807,"journal":{"name":"Quantum","volume":"18 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138536","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}
Zhi-Jun Qin, Zhao-Hua Xu, Hui Zheng, Ya-Qi Song, Hang Ren, Wen-Ya Wang, Hong Chen, Jia-Jun Liang, Xiao-Liang Ge, Guan-Long Huang, Su Xu
Manipulating circular-, elliptical-, and linear- polarization states of radiation and enhancing the matching efficiency between radiators and receivers/detectors, emerges as a cornerstone technology for achieving high-quality wireless communications and radar detections. However, reconfiguring these polarization states freely in the chip is still an open challenge over the sub-terahertz (sub-THz) band. Here, we achieve broadband sub-THz polarization-reconfigurable on-chip radiation based on a spoof surface plasmon polaritons (SSPPs) platform. By modulating the asymmetric near-field coupling between the SSPP waveguide and scatter arrays, continuous adjustment of the axial ratio is observed numerically from 1 to 40 dB, enabling the flexible switching among all three classes of polarization states. The experiment also demonstrates this powerful dynamic polarization switching functionality. Our work broadens on-chip dynamic manipulation of sub-THz and THz waves and may also open an avenue to secure communication, satellite networks, and local data-center interconnects.
{"title":"Sub-Terahertz Broadband Polarization-Reconfigurable Radiation Based on Spoof Surface Plasmon Polaritons","authors":"Zhi-Jun Qin, Zhao-Hua Xu, Hui Zheng, Ya-Qi Song, Hang Ren, Wen-Ya Wang, Hong Chen, Jia-Jun Liang, Xiao-Liang Ge, Guan-Long Huang, Su Xu","doi":"10.1002/lpor.202502111","DOIUrl":"https://doi.org/10.1002/lpor.202502111","url":null,"abstract":"Manipulating circular-, elliptical-, and linear- polarization states of radiation and enhancing the matching efficiency between radiators and receivers/detectors, emerges as a cornerstone technology for achieving high-quality wireless communications and radar detections. However, reconfiguring these polarization states freely in the chip is still an open challenge over the sub-terahertz (sub-THz) band. Here, we achieve broadband sub-THz polarization-reconfigurable on-chip radiation based on a spoof surface plasmon polaritons (SSPPs) platform. By modulating the asymmetric near-field coupling between the SSPP waveguide and scatter arrays, continuous adjustment of the axial ratio is observed numerically from 1 to 40 dB, enabling the flexible switching among all three classes of polarization states. The experiment also demonstrates this powerful dynamic polarization switching functionality. Our work broadens on-chip dynamic manipulation of sub-THz and THz waves and may also open an avenue to secure communication, satellite networks, and local data-center interconnects.","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"198 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138820","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}
Pub Date : 2026-02-09DOI: 10.1021/acsphotonics.5c02076
Rafael S. Dutra,Felipe A. Pinheiro,Diney S. Ether Jr.,Cyriaque Genet,Nathan B. Viana,Paulo A. Maia Neto
We demonstrate that an effect phenomenologically analogous to circular dichroism can arise even for dielectric and isotropic chiral spherical particles. By analyzing the polarimetry of light scattered from a chiral, lossless microsphere illuminated with linearly polarized light, we show that the scattered light becomes nearly circularly polarized, exhibiting large nonresonant values of the Stokes parameter S3 for a broad range of visible frequencies. This phenomenon occurs only in the Mie regime, with the microsphere radius comparable to the wavelength, and provided that the scattered light is collected by a high-NA objective lens, including nonparaxial Fourier components. Altogether, our findings offer a theoretical framework and motivation for an experimental demonstration of a novel chiroptical effect with isolated dielectric particles, with potential applications in enantioselection and characterization of single microparticles, each and every one with its own chiral response.
{"title":"Circular Dichroism without Absorption in Isolated Chiral Dielectric Mie Particles","authors":"Rafael S. Dutra,Felipe A. Pinheiro,Diney S. Ether Jr.,Cyriaque Genet,Nathan B. Viana,Paulo A. Maia Neto","doi":"10.1021/acsphotonics.5c02076","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c02076","url":null,"abstract":"We demonstrate that an effect phenomenologically analogous to circular dichroism can arise even for dielectric and isotropic chiral spherical particles. By analyzing the polarimetry of light scattered from a chiral, lossless microsphere illuminated with linearly polarized light, we show that the scattered light becomes nearly circularly polarized, exhibiting large nonresonant values of the Stokes parameter S3 for a broad range of visible frequencies. This phenomenon occurs only in the Mie regime, with the microsphere radius comparable to the wavelength, and provided that the scattered light is collected by a high-NA objective lens, including nonparaxial Fourier components. Altogether, our findings offer a theoretical framework and motivation for an experimental demonstration of a novel chiroptical effect with isolated dielectric particles, with potential applications in enantioselection and characterization of single microparticles, each and every one with its own chiral response.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"3 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138827","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}
Pub Date : 2026-02-09DOI: 10.1088/1475-7516/2026/02/025
V.T. Voronchev
The present paper completes a series of our works on non-thermal nuclear processes in big bang nucleosynthesis (BBN) started in JCAP 05 (2008) 010 (Part I) and 05 (2009) 001 (Part II). The processes are triggered by non-Maxwellian particles naturally born in the main BBN reactions. Half of these reactions generate fast particles k+ (= n,p,t,3He,α). The other half, being radiative capture processes, produce slow nuclei k- (= d,t,3He,7Li,7Be) which can undergo (k-,n) reactions with neutrons having large cross sections. The particle production rate Rk, thermalization time τk, and effective number density nk are determined. It is shown that at the early stage of BBN the number density of slow deuterons (respectively, 3He) can exceed the number densities of Maxwellian 7Li and 7Be (respectively, 7Be) ions. To clarify the overall non-Maxwellian effect on BBN, both types of the non-Maxwellian particles are taken into account in the reaction network. Particular attention is paid to two-step sequential processes like p(n,γ)d-(n,γ)t, d(p,γ)3He-(n,p)t, t(α,γ)7Li-(n,γ)8Li, 3He(α,γ)7Be-(n,p)7Li, d(t,α)n+(A,n)a1a2, and d(3He,α)p+(A,p)a1a2 with (A,a1,a2) = (7Li,t,α) and (7Be,3He,α). It is obtained that the non-Maxwellian particles can selectively affect the element abundances, e.g., improve the prediction on 7Li/H by ∼ 1.5% and at the same time leave unchanged the 4He abundance. The main conclusion however is that these particles are unable to significantly change the standard picture of BBN in general, and provide a pathway toward a solution of the cosmological lithium problem in particular.
{"title":"Non-thermal processes in standard big bang nucleosynthesis. Part III. Reactions with slow nuclei and the overall effect","authors":"V.T. Voronchev","doi":"10.1088/1475-7516/2026/02/025","DOIUrl":"https://doi.org/10.1088/1475-7516/2026/02/025","url":null,"abstract":"The present paper completes a series of our works on non-thermal nuclear processes in big bang nucleosynthesis (BBN) started in JCAP 05 (2008) 010 (Part I) and 05 (2009) 001 (Part II). The processes are triggered by non-Maxwellian particles naturally born in the main BBN reactions. Half of these reactions generate fast particles k+ (= n,p,t,3He,α). The other half, being radiative capture processes, produce slow nuclei k- (= d,t,3He,7Li,7Be) which can undergo (k-,n) reactions with neutrons having large cross sections. The particle production rate Rk, thermalization time τk, and effective number density nk are determined. It is shown that at the early stage of BBN the number density of slow deuterons (respectively, 3He) can exceed the number densities of Maxwellian 7Li and 7Be (respectively, 7Be) ions. To clarify the overall non-Maxwellian effect on BBN, both types of the non-Maxwellian particles are taken into account in the reaction network. Particular attention is paid to two-step sequential processes like p(n,γ)d-(n,γ)t, d(p,γ)3He-(n,p)t, t(α,γ)7Li-(n,γ)8Li, 3He(α,γ)7Be-(n,p)7Li, d(t,α)n+(A,n)a1a2, and d(3He,α)p+(A,p)a1a2 with (A,a1,a2) = (7Li,t,α) and (7Be,3He,α). It is obtained that the non-Maxwellian particles can selectively affect the element abundances, e.g., improve the prediction on 7Li/H by ∼ 1.5% and at the same time leave unchanged the 4He abundance. The main conclusion however is that these particles are unable to significantly change the standard picture of BBN in general, and provide a pathway toward a solution of the cosmological lithium problem in particular.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"59 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138358","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}
Pub Date : 2026-02-09DOI: 10.22331/q-2026-02-09-2000
Anthony Leverrier
While 2-level systems, aka qubits, are a natural choice to perform a logical quantum computation, the situation is less clear at the physical level. Encoding information in higher-dimensional physical systems can indeed provide a first level of redundancy and error correction that simplifies the overall fault-tolerant architecture. A challenge then is to ensure universal control over the encoded qubits. Here, we explore an approach where information is encoded in an irreducible representation of a finite subgroup of $U(2)$ through an inverse quantum Fourier transform. We illustrate this idea by applying it to the real Pauli group $langle X, Zrangle$ in the bosonic setting. The resulting two-mode Fourier cat code displays good error correction properties and admits an experimentally-friendly universal gate set that we discuss in detail.
{"title":"Bosonic quantum Fourier codes","authors":"Anthony Leverrier","doi":"10.22331/q-2026-02-09-2000","DOIUrl":"https://doi.org/10.22331/q-2026-02-09-2000","url":null,"abstract":"While 2-level systems, aka qubits, are a natural choice to perform a logical quantum computation, the situation is less clear at the physical level. Encoding information in higher-dimensional physical systems can indeed provide a first level of redundancy and error correction that simplifies the overall fault-tolerant architecture. A challenge then is to ensure universal control over the encoded qubits. Here, we explore an approach where information is encoded in an irreducible representation of a finite subgroup of $U(2)$ through an inverse quantum Fourier transform. We illustrate this idea by applying it to the real Pauli group $langle X, Zrangle$ in the bosonic setting. The resulting two-mode Fourier cat code displays good error correction properties and admits an experimentally-friendly universal gate set that we discuss in detail.","PeriodicalId":20807,"journal":{"name":"Quantum","volume":"241 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138510","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}
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