Physica B-condensed Matter最新文献

{"title":"Chiral-induced circularly polarized light emission from a single-molecule junction","authors":"Natalya A. Zimbovskaya","doi":"10.1016/j.physb.2025.417786","DOIUrl":"10.1016/j.physb.2025.417786","url":null,"abstract":"<div><div>In the present work we theoretically analyze electroluminescence occurring in a biased single-molecule junction with a chiral bridge imitated by a helical chain. We show that optical transitions between electron states of the chiral linker may result in the emission of circular polarized light whose handedness depends on both direction of propagation and the polarity of the bias voltage provided that the coupling between the bridge sites is sufficiently strong. The mechanism controlling this specific light emission does not depend on the magnetic moments and spin–orbit interactions. It rather relies on the chiral properties of the bridge molecule and on the distribution of the bias voltage between the electrodes in the junction.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"717 ","pages":"Article 417786"},"PeriodicalIF":2.8,"publicationDate":"2025-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096714","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}

{"title":"Analysis of many-body localization transitions in Floquet systems: Random versus quasi-periodic disorder","authors":"Longhui Shen,&nbsp;Mingxiang Gao,&nbsp;Xiuquan Yu,&nbsp;Bin Guo","doi":"10.1016/j.physb.2025.417780","DOIUrl":"10.1016/j.physb.2025.417780","url":null,"abstract":"<div><div>We investigate many-body localization (MBL) phase transitions in Floquet-driven quantum systems, employing global quantum discord (GQD) to compare the stability and dynamics of MBL phases under random and quasi-periodic disorder. For a static Heisenberg spin-<span><math><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></math></span> ladder, GQD reveals critical disorder strengths of <span><math><mrow><msub><mrow><mi>W</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>≈</mo><mn>9</mn><mo>.</mo><mn>5</mn></mrow></math></span> (random case) and <span><math><mrow><msub><mrow><mi>W</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>≈</mo><mn>8</mn><mo>.</mo><mn>5</mn></mrow></math></span> (quasi-periodic case), highlighting the greater stability of quasi-periodic disorder. In Floquet systems, high-frequency drives (<span><math><mrow><mi>ω</mi><mo>&gt;</mo><mn>20</mn></mrow></math></span>) suppress energy absorption, preserving MBL even in weakly disordered ergodic regimes, while low frequencies (<span><math><mrow><mi>ω</mi><mo>&lt;</mo><mn>2</mn></mrow></math></span>) or strong amplitudes promote thermalization. Quasi-periodic disorder exhibits superior resistance to thermalization, with higher critical driving amplitudes, attributed to robust internal correlations quantified by GQD. Variance analysis confirms the consistency of these critical points. Our findings clarify the distinct stabilization mechanisms of driving parameters in Floquet-MBL systems, while demonstrating quasi-periodic disorder’s inherent robustness against perturbations, offering guidance for the experimental realization of nonergodic quantum states.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"717 ","pages":"Article 417780"},"PeriodicalIF":2.8,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096775","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}

{"title":"Pressure-dependent properties of muoniated radicals in an electron acceptor crystal studied using avoided level crossing muon spectroscopy","authors":"Yue Yuan ,&nbsp;Li Deng ,&nbsp;Ziwen Pan ,&nbsp;Bangjiao Ye ,&nbsp;Francis L. Pratt","doi":"10.1016/j.physb.2025.417779","DOIUrl":"10.1016/j.physb.2025.417779","url":null,"abstract":"<div><div>Muon spin spectroscopy is a powerful tool for probing magnetism and electron configurations in materials. In the electron acceptor TCNQ, implanted polarised positive muons form radicals with a delocalised unpaired electron. Using avoided level crossing (ALC) spectroscopy under pressures up to 6 kbar, we observed upward shifts in resonance fields, suggesting an increase in muon hyperfine coupling constant <span><math><msub><mrow><mi>A</mi></mrow><mrow><mi>μ</mi></mrow></msub></math></span>. First-principles calculations with quantum corrections identified two muon addition sites: a bridging carbon and a terminal nitrogen. Statistical analysis of relaxed structures from random muon positions showed how site basins of attraction change with pressure, revealing a shift in site populations. Simulated ALC spectra using DFT parameters reproduced the observed shifts. This indicates the pressure-dependent resonance shift arises not from a direct change in <span><math><msub><mrow><mi>A</mi></mrow><mrow><mi>μ</mi></mrow></msub></math></span>, but from redistribution between muon sites due to modifications in the local energy landscape.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"717 ","pages":"Article 417779"},"PeriodicalIF":2.8,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096843","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}

{"title":"High-performance and flexible Mo2C/Gd2O3-based polymer composite films for EMI absorption in the X-band region","authors":"Lalitha Durairaj ,&nbsp;Malathi Murugesan","doi":"10.1016/j.physb.2025.417804","DOIUrl":"10.1016/j.physb.2025.417804","url":null,"abstract":"<div><div>To mitigate secondary electromagnetic pollution, there has been increasing interest in absorption-dominant electromagnetic interference (EMI) absorbing materials. This study presents the preparation of Gadolinium oxide (Gd₂O₃) and molybdenum carbide (Mo₂C) polymer composite films using the solution casting technique, aimed at high-performance EMI shielding applications. The focus is on the innovative and cost-effective development of a composite film incorporating PVDF nanocomposite designed to reduce EMI. The resulting nanocomposite demonstrated an impressive shielding effectiveness of 51 dB in experimental configurations, utilizing equal amounts of gadolinium oxide and molybdenum carbide at a film thickness of 0.21 mm. Efficiency measurements validate the loss of incoming electromagnetic energy, which is supported through the absorption-dominated EMI shielding mechanism, which is described by strong interfacial polarization. The tensile strength, stress, and strain of the composites were evaluated using various characterization methods, showcasing their superior mechanical properties. The CST simulation process was employed to validate the theoretical values.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"717 ","pages":"Article 417804"},"PeriodicalIF":2.8,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096844","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}

{"title":"Effect of thallium bromide and gold layer thickness on the optical performance of surface plasmon resonance sensors","authors":"Bhishma Karki ,&nbsp;Youssef Trabelsi ,&nbsp;Rajeev Kumar ,&nbsp;Subbulakshmi Ganesan ,&nbsp;Alok Kumar Mishra ,&nbsp;T. Krithiga ,&nbsp;Sanjeev Kumar","doi":"10.1016/j.physb.2025.417803","DOIUrl":"10.1016/j.physb.2025.417803","url":null,"abstract":"<div><div>For high-sensitivity biosensing applications, this work offers a thorough examination of multilayer surface plasmon resonance (SPR) sensor structures based on different silver (Ag), thallium bromide (TIBr), gold (Au), and black phosphorus (BP) layer thicknesses to maximize optical performance. Resonance angle shift (Δθ_res), sensitivity (S), reflectance minimum (R_min), full width at half maximum (FWHM), detection accuracy (DA), and figure of merit (FoM) were among the important metrics used to assess the sensor. The structure that had 45 nm Ag and 1 nm TIBr with an Au (1 nm) layer showed the best balance between a high sensitivity (368.38 _°/RIU), low R_min (0.018), and remarkable FoM of 128.9<em>/RIU</em>. Without an Au layer, the maximum sensitivity of 372.19<em>°/RIU</em> and FoM of 104.21<em>/RIU</em> is obtained at 38 nm Ag thickness. Through carefully calibrated multilayer compositions, these findings offer important insights into the design of high-performance SPR sensors.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"717 ","pages":"Article 417803"},"PeriodicalIF":2.8,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096853","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}

{"title":"Effect of gamma irradiation and thermal annealing on defect formation in ZrB2 nanocrystals","authors":"S.F. Samadov ,&nbsp;O.A. Samedov ,&nbsp;D.M. Mirzayeva ,&nbsp;H.H.A. Nguyen ,&nbsp;M.N. Mirzayev","doi":"10.1016/j.physb.2025.417807","DOIUrl":"10.1016/j.physb.2025.417807","url":null,"abstract":"<div><div>The study investigated the microstructural changes and defect formation for ZrB₂ nanocrystalline sample (grain size: 43 nm) under the effect of irradiation and combined effects of irradiation and thermal annealing. The sample was irradiated using a ⁶⁰Co gamma-ray source at a dose rate of 6.05 Gy/h, with total absorbed dose of 1500 and 3000 kGy. Raman spectroscopic analysis showed that the degree of amorphization increases up to 1.2 % for the sample irradiated with absorption dose 3000 kGy, while a 0.2 % decrease was observed after thermal treatment at 1173 K. moreover the broadening of Raman peaks and the decrease in intensity after thermal treatment confirm the persistence of defect states in the crystalline structure. Doppler Broadening Positron Annihilation Spectroscopy (DBPAS) results revealed that the S parameter increased within the range of 3.1–3.6 %, while the W parameter decreased within the range of 2.8–2.4 %. The variation of the S and W components indicates the formation of free-volume defects, as well as Zr and B vacancies in the crystal structure ZrB₂ nanocrystalline sample. Ab initio calculations based on the two-component density functional theory (TCDFT) showed the formation of 1V_Zr, 2V_Zr+1V_B, and 3V_Zr+2V_B vacancy complexes. In the electron momentum density (EMD) spectra, characteristic intensity variations were detected in the range of 0.0–4.0 × 10⁻³ m₀c.</div><div>After combined effect of irradiation and thermal treatment, the highly defective EMD features demonstrate that the recombination of defect centers significantly decreases. The research results show that in ZrB₂ material irradiated at a high absorbed dose, complex vacancy-type defects are formed, and depending on the selected temperature interval, effective recombination of defects occurs. All these findings suggest that nanocrystalline ZrB₂ is a promising material for future applications as a radiation-resistant ceramic.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"717 ","pages":"Article 417807"},"PeriodicalIF":2.8,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096847","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}

{"title":"Interfacial engineering and dielectric tunability in Ag/Al/SiO2/n-Si/Ag heterostructures: Novel insights for resistive memory and high-κ electronics","authors":"A. Ashery","doi":"10.1016/j.physb.2025.417758","DOIUrl":"10.1016/j.physb.2025.417758","url":null,"abstract":"<div><div>This study presents a comprehensive investigation of the dielectric and electrical properties of Ag/Al/SiO₂/n-Si/Ag heterostructures using impedance spectroscopy, modulus formalism, and temperature-dependent current-voltage (I-V) analysis. The incorporation of an Al interlayer between Ag and SiO₂ introduces unique interfacial effects, modifying charge transport dynamics, dielectric relaxation, and barrier height distribution. Key findings include: Frequency- and voltage-dependent dielectric relaxation, revealing Maxwell-Wagner polarization and interfacial trap effects, with non-Debye behavior due to distributed relaxation times. Temperature-activated conduction mechanisms, including thermionic emission, hopping transport, and space-charge-limited conduction (SCLC), influenced by SiO₂ thickness and defect states.AC conductivity analysis following Jonscher's power law, with distinct low-frequency (ohmic) and high-frequency (dispersive) regimes. Barrier height inhomogeneity, extracted via modified Richardson plots, showing a Gaussian distribution of Schottky barriers due to interfacial disorder. Novelty: Unlike conventional MOS structures, the dual-metal (Ag/Al) electrode enhances interfacial dipoles and modifies charge injection, while the SiO₂/n-Si interface governs dielectric losses and capacitive memory effects. This work bridges the gap between organic-inorganic hybrid dielectrics and traditional SiO₂-based devices, offering insights into defect engineering for tunable dielectric response. Potential Applications.</div><div>Non-volatile resistive memory (RRAM) – Exploiting voltage-dependent dielectric relaxation for low-power neuromorphic computing. High-κ gate dielectrics – Optimizing SiO₂ thickness for reduced leakage currents in MOSFETs. Flexible electronics – Hybridizing with polymer composites (e.g., P3HT:PCBM) for stretchable capacitive sensors. Thermal/voltage sensors – Utilizing tanδ and modulus dispersion for environmental sensing applications.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"717 ","pages":"Article 417758"},"PeriodicalIF":2.8,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096774","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}

{"title":"Performance analysis of reconfigurable magnetic tunnel junction based on SGS and HMM materials under bias voltages in VSe2/hBN/MnSe2","authors":"Shagufta Parveen Asif Akhtar,&nbsp;Santashraya Prasad,&nbsp;Aminul Islam","doi":"10.1016/j.physb.2025.417806","DOIUrl":"10.1016/j.physb.2025.417806","url":null,"abstract":"<div><div>Magnetic tunnel junctions (MTJs) are key components in spintronic devices, where performance is strongly influenced by the choice of electrode and barrier materials. This work investigates a reconfigurable MTJ based on a VSe₂/hBN/MnSe₂ heterostructure using first-principles and quantum transport simulations. VSe₂ acts as a spin-gapless semiconductor, MnSe₂ as a half-metallic magnet, and hBN as a two-dimensional tunneling barrier. The device demonstrates an inverse tunnel magnetoresistance (TMR) effect with diode-like behavior across −0.5 to 0.5 V. A maximum TMR of 2060.01 % is obtained at −0.5 V, while −79.11 % appears at +0.5 V. Vacancy analysis at zero bias reveals that Mn-site defects suppress TMR to −100.00 %, whereas V-site vacancy produce a less severe reduction, with TMR at −37.81 %. Combining spin-gapless semiconductor and half-metallic magnet electrodes with a van der Waals barrier enhances spin filtering, tunability, and multifunctional transport, making this design promising for energy-efficient spintronic memory and logic applications.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"717 ","pages":"Article 417806"},"PeriodicalIF":2.8,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096716","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}

{"title":"The effect of pressure, temperature and Al concentration on linear and nonlinear optical properties of symmetric and asymmetric double triangular quantum dots","authors":"Emre Bahadir AL ,&nbsp;Norshamsuri Ali ,&nbsp;Rosdisham Endut ,&nbsp;Syed Alwee Aljunid ,&nbsp;Nor Roshidah Yusof ,&nbsp;Muhamad Asmi Romli","doi":"10.1016/j.physb.2025.417797","DOIUrl":"10.1016/j.physb.2025.417797","url":null,"abstract":"<div><div>This study theoretically investigates the linear and third-order nonlinear optical absorption coefficients and relative refractive index changes in symmetric and asymmetric double triangular potential-shaped spherical quantum dots. We examine the effects of temperature, pressure, and aluminum concentration on these optical properties. Using the compact density matrix approach and iterative procedure, we derive analytical expressions for the linear and nonlinear optical properties, with energies and wave functions calculated within the effective mass and parabolic band approximations. Numerical results are presented for a typical GaAs/AlGaAs material system. The findings reveal distinct influences of temperature, pressure, and Al concentration on the optical properties, with differences in resonance frequency and nonlinear contributions between symmetric and asymmetric structures. These results demonstrate that hydrostatic pressure, temperature, and Al concentration significantly affect the electronic and optical properties of double triangular quantum dots, enabling the tuning of optical responses and optimization of inter-subband transitions for optoelectronic applications.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"717 ","pages":"Article 417797"},"PeriodicalIF":2.8,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096776","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}

{"title":"Synthesized α-V2O5 nanoparticles and explored their performance as gas sensors in an ammonia atmosphere","authors":"Surya Prakash Singh ,&nbsp;Satyam Tripathi ,&nbsp;Atul Kumar ,&nbsp;Vijay Prajapati ,&nbsp;Jyoti Yadav ,&nbsp;Ravindra Kumar Rawat ,&nbsp;Pratima Chauhan","doi":"10.1016/j.physb.2025.417782","DOIUrl":"10.1016/j.physb.2025.417782","url":null,"abstract":"<div><div>Metal oxide semiconductor (MOS) chemiresistive sensors are effective for detecting ammonia (NH₃), but need high temperatures and have low sensitivity. This work investigates hydrothermally produced α-V₂O₅ irregular nanodiscs as a possible NH₃ sensor for ambient conditions. XRD, UV–vis spectroscopy, FE-SEM, HR-TEM, EDX mapping, and FT-IR were used to identify the material's structure, morphology, composition, and functional groups. The crystallite size (∼27 nm) and band gap (3.4 eV) were determined using the Debye-Scherrer and Tauc equations, respectively, suggesting excellent electronic characteristics. The sensor was tested at 50–500 ppm NH₃ concentrations and shown great sensitivity with quick response (22 s) and recovery (17 s). Importantly, performance remained consistent across various relative humidity levels, suggesting resilience to environmental conditions. These findings suggest that α-V₂O₅ nanodiscs are potentially effective for current time ammonia detection at ambient temperature.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":"717 ","pages":"Article 417782"},"PeriodicalIF":2.8,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096879","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}