Pub Date : 2024-09-25DOI: 10.1016/j.physb.2024.416561
In this study, we introduced a model utilizing a plasmonic nanostructure to modulate the entanglement between atoms and photons within a V-type atomic medium. This system is influenced by composite optical vortex light (COVL) and two incoherent pumping fields. The plasmonic nanostructure comprises dielectric nanospheres, which have been thoroughly investigated (Phys. Rev. B 106, 035419, 2022). By adjusting the orbital angular momentum (OAM) of COVL, we demonstrate that the nanostructure induces significant spatial variations in the degree of entanglement (DEM). Additionally, incorporating a weak incoherent pumping field affects the DEM profile within the hybrid system. Our findings reveal that the OAM of structured light can govern the spatial dependence of DEM, particularly when quantum interference from the nanostructure and pumping fields surpasses a specific threshold. Furthermore, our results suggest that analyzing the DEM profile's spatial regions can be employed to determine the OAM number of the structured light.
在这项研究中，我们介绍了一种利用质子纳米结构来调节 V 型原子介质中原子与光子之间纠缠的模型。该系统受到复合光学涡旋光（COVL）和两个非相干泵浦场的影响。质子纳米结构由介电纳米球组成，这些纳米球已经过深入研究（Phys. Rev. B 106, 035419, 2022）。通过调整 COVL 的轨道角动量 (OAM)，我们证明这种纳米结构会引起纠缠度 (DEM) 的显著空间变化。此外，加入微弱的非相干抽运场也会影响混合系统内的 DEM 曲线。我们的研究结果表明，结构光的 OAM 可以控制 DEM 的空间依赖性，尤其是当来自纳米结构和泵浦场的量子干扰超过特定阈值时。此外，我们的研究结果表明，通过分析 DEM 曲线的空间区域，可以确定结构光的 OAM 数量。
{"title":"Spatially hybrid control of entanglement between atom and photon","authors":"","doi":"10.1016/j.physb.2024.416561","DOIUrl":"10.1016/j.physb.2024.416561","url":null,"abstract":"<div><div>In this study, we introduced a model utilizing a plasmonic nanostructure to modulate the entanglement between atoms and photons within a V-type atomic medium. This system is influenced by composite optical vortex light (COVL) and two incoherent pumping fields. The plasmonic nanostructure comprises dielectric nanospheres, which have been thoroughly investigated (Phys. Rev. B 106, 035419, 2022). By adjusting the orbital angular momentum (OAM) of COVL, we demonstrate that the nanostructure induces significant spatial variations in the degree of entanglement (DEM). Additionally, incorporating a weak incoherent pumping field affects the DEM profile within the hybrid system. Our findings reveal that the OAM of structured light can govern the spatial dependence of DEM, particularly when quantum interference from the nanostructure and pumping fields surpasses a specific threshold. Furthermore, our results suggest that analyzing the DEM profile's spatial regions can be employed to determine the OAM number of the structured light.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357922","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 : 2024-09-24DOI: 10.1016/j.physb.2024.416572
This work reports the modelling and numerical estimation of the photovoltaic parameters of perovskite solar cells (PSCs) containing formamidinium lead iodide (FAPbI3) and formamidinium tin iodide (FASnI3) in the form of light active materials using SCAPS 1D software. The analysis is done by introducing diverse hole and electron transport materials and back metal contacts to identify the most appropriate device configuration that can deliver optimum photovoltaic output. The optoelectronic properties and the absorption spectra of the two compounds are estimated by DFT calculation using WIEN2k, which incorporates density functional theory (DFT) principles and are provided as input to SCAPS 1D to improve the accuracy of modelling study. For FAPbI3 as absorber material, the configuration FTO/IGZO/FAPbI3/NiO/Au shows the highest photovoltaic parameter exhibiting a power conversion efficiency (PCE) and fill factor (FF) of 19.75 % and 74.29 % respectively. With FASnI3 as the absorber material, FTO/PCBM/FASnI3/P3HT/Au gives a PCE and FF of 21.6 % and 67.74 % respectively. The work also includes the analysis of influence of defect density at the interface layers and series and shunt resistance on performance of above-mentioned device architectures to identify their limitations under real experimental conditions. The influence of various attributes of perovskite on the performance of the device is examined to determine their optimum values.
{"title":"A combined DFT and finite difference simulation study on hybrid halide perovskite-based solar cells","authors":"","doi":"10.1016/j.physb.2024.416572","DOIUrl":"10.1016/j.physb.2024.416572","url":null,"abstract":"<div><div>This work reports the modelling and numerical estimation of the photovoltaic parameters of perovskite solar cells (PSCs) containing formamidinium lead iodide (FAPbI<sub>3</sub>) and formamidinium tin iodide (FASnI<sub>3</sub>) in the form of light active materials using SCAPS 1D software. The analysis is done by introducing diverse hole and electron transport materials and back metal contacts to identify the most appropriate device configuration that can deliver optimum photovoltaic output. The optoelectronic properties and the absorption spectra of the two compounds are estimated by DFT calculation using WIEN2k, which incorporates density functional theory (DFT) principles and are provided as input to SCAPS 1D to improve the accuracy of modelling study. For FAPbI<sub>3</sub> as absorber material, the configuration FTO/IGZO/FAPbI<sub>3</sub>/NiO/Au shows the highest photovoltaic parameter exhibiting a power conversion efficiency (PCE) and fill factor (FF) of 19.75 % and 74.29 % respectively. With FASnI<sub>3</sub> as the absorber material, FTO/PCBM/FASnI<sub>3</sub>/P3HT/Au gives a PCE and FF of 21.6 % and 67.74 % respectively. The work also includes the analysis of influence of defect density at the interface layers and series and shunt resistance on performance of above-mentioned device architectures to identify their limitations under real experimental conditions. The influence of various attributes of perovskite on the performance of the device is examined to determine their optimum values.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318993","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 : 2024-09-24DOI: 10.1016/j.physb.2024.416573
In this study, we have explored the electronic, optical, and mechanical properties of MgTa2O6 compounds in both tetragonal and orthorhombic phases using the first principles based on density functional theory (DFT) methods. Considering that GGA underestimates the band gap of materials, the HSE06 hybrid functional is performed to get a more accurate result for the band structure and optical property calculations. The calculations indicate that the tetragonal and orthorhombic phases exhibit different optical characteristics, showcasing their potential as exceptional materials for UV absorption. In addition, we have thoroughly investigated the elastic properties of MgTa2O6 for these two phases, including the bulk modulus, shear modulus, Young's modulus, and Poisson's ratio. The results indicate that the tetragonal phase has better volume deformation and shear deformation resistance, and the surface contours of Young's modulus for MgTa2O6 display anisotropy. And according to Pugh's criteria, the tetragonal phase has good ductile properties.
{"title":"Mechanical and optical properties of MgTa2O6 compounds: First principles study","authors":"","doi":"10.1016/j.physb.2024.416573","DOIUrl":"10.1016/j.physb.2024.416573","url":null,"abstract":"<div><div>In this study, we have explored the electronic, optical, and mechanical properties of MgTa<sub>2</sub>O<sub>6</sub> compounds in both tetragonal and orthorhombic phases using the first principles based on density functional theory (DFT) methods. Considering that GGA underestimates the band gap of materials, the HSE06 hybrid functional is performed to get a more accurate result for the band structure and optical property calculations. The calculations indicate that the tetragonal and orthorhombic phases exhibit different optical characteristics, showcasing their potential as exceptional materials for UV absorption. In addition, we have thoroughly investigated the elastic properties of MgTa<sub>2</sub>O<sub>6</sub> for these two phases, including the bulk modulus, shear modulus, Young's modulus, and Poisson's ratio. The results indicate that the tetragonal phase has better volume deformation and shear deformation resistance, and the surface contours of Young's modulus for MgTa<sub>2</sub>O<sub>6</sub> display anisotropy. And according to Pugh's criteria, the tetragonal phase has good ductile properties.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323003","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 : 2024-09-24DOI: 10.1016/j.physb.2024.416568
This study investigates the structural and optical properties of TlInS2 crystals under elevated pressures using density functional theory (DFT). The dielectric function shows significant shifts under pressure, indicating changes in electronic transitions and band structures. Analysis of the refractive index reveals pressure-induced spectral peaks and a semiconductor-to-metal transition at 6.25 GPa. Reflectivity measurements show an increase with pressure, reaching 0.504 at 10 GPa, suggesting enhanced optical properties. Optical conductivity analysis shows increased total conductivity with pressure due to reduced band gap energy, stimulating exciton formation and metallic behavior beyond 6.25 GPa. These comprehensive insights into the pressure-dependent behaviors of TlInS2 are essential for potential applications in electronic and optoelectronic devices.
{"title":"Pressure-dependent optoelectronic properties of TlInS2 crystals (II): Insights from DFT simulations","authors":"","doi":"10.1016/j.physb.2024.416568","DOIUrl":"10.1016/j.physb.2024.416568","url":null,"abstract":"<div><div>This study investigates the structural and optical properties of TlInS<sub>2</sub> crystals under elevated pressures using density functional theory (DFT). The dielectric function shows significant shifts under pressure, indicating changes in electronic transitions and band structures. Analysis of the refractive index reveals pressure-induced spectral peaks and a semiconductor-to-metal transition at 6.25 GPa. Reflectivity measurements show an increase with pressure, reaching 0.504 at 10 GPa, suggesting enhanced optical properties. Optical conductivity analysis shows increased total conductivity with pressure due to reduced band gap energy, stimulating exciton formation and metallic behavior beyond 6.25 GPa. These comprehensive insights into the pressure-dependent behaviors of TlInS<sub>2</sub> are essential for potential applications in electronic and optoelectronic devices.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323004","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 : 2024-09-22DOI: 10.1016/j.physb.2024.416558
Discharge of hazardous industrial effluents cause environmental pollution and induce health related problems in living organisms. Multifunctional Ag-Mo-WO3 NPs were developed via green combustion method using Mentha spicata as a novel fuel. XRD studies confirmed the formation of tetragonal structured WO3 successfully doped with Ag and W into its crystal lattice. Tauc plot confirmed the reduction in band gap of WO3 (2.77 eV) due to doping. SEM, TEM and EDX studies demonstrate the formation pure NPs with unique morphology having particle size in the range of ∼30–40 nm. Photodegradation studies revealed that 60 mg of NPs degraded MB dye completely in a short span of 30 min. The NPs showed good sensitivity towards electrocatalytic detection of NaNO2 with the LOD value of 21.23 μM. Further, the NPs proved to possess excellent photoluminescent and antioxidant activities. Doping improved its effective absorption of visible light that aid in the formation of electron hole pairs which in turn enhanced its multifunctional properties. The research manifests a simple, economical and eco-friendly synthetic method for synthesizing Ag-Mo-WO3 NPs on a large scale.
{"title":"Multifaceted Ag-Mo-WO3 for superior photocatalytic, luminescence, sensing and antioxidant activities","authors":"","doi":"10.1016/j.physb.2024.416558","DOIUrl":"10.1016/j.physb.2024.416558","url":null,"abstract":"<div><div>Discharge of hazardous industrial effluents cause environmental pollution and induce health related problems in living organisms. Multifunctional Ag-Mo-WO<sub>3</sub> NPs were developed via green combustion method using <em>Mentha spicata</em> as a novel fuel. XRD studies confirmed the formation of tetragonal structured WO<sub>3</sub> successfully doped with Ag and W into its crystal lattice. Tauc plot confirmed the reduction in band gap of WO<sub>3</sub> (2.77 eV) due to doping. SEM, TEM and EDX studies demonstrate the formation pure NPs with unique morphology having particle size in the range of ∼30–40 nm. Photodegradation studies revealed that 60 mg of NPs degraded MB dye completely in a short span of 30 min. The NPs showed good sensitivity towards electrocatalytic detection of NaNO<sub>2</sub> with the LOD value of 21.23 μM. Further, the NPs proved to possess excellent photoluminescent and antioxidant activities. Doping improved its effective absorption of visible light that aid in the formation of electron hole pairs which in turn enhanced its multifunctional properties. The research manifests a simple, economical and eco-friendly synthetic method for synthesizing Ag-Mo-WO<sub>3</sub> NPs on a large scale.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315206","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 : 2024-09-21DOI: 10.1016/j.physb.2024.416538
The objective of this study is to enhance the utilization of ABI3 (A = Rb, Cs; B = Ca, Sr) metal-halide perovskites in multiple forms of technological applications by investigating their structural, electronic, optical, and mechanical characteristics using the ab initio method. At ambient pressure, the geometry-optimized lattice constants for RbCaI3, RbSrI3, CsCaI3, and CsSrI3 are 6.19 Å, 6.45 Å, 6.22 Å, and 6.47 Å, respectively, consistent with prior research. Additionally, a significant decrease in lattice parameters and bond length is observed, which leads to increased levels of atomic interactions. Pressure narrows the band gap from the ultraviolet-to-visible region. This phenomenon promotes the transfer of electrons from the valence-to-conduction band, hence improving the performance of optoelectronic devices. Furthermore, a shift from an indirect to a direct band gap is induced by the application of pressure, which improves the material's suitability for photovoltaic applications. The covalent and ionic nature of Ca/Sr-I and Rb/Cs-I under pressure and without pressure conditions was determined using the charge density maps. Enhanced pressure significantly boosts optical absorption and conductivity in the visible spectrum, implying substantial potential for improving the efficacy of perovskite solar cells and photonic devices. Additionally, applied pressure significantly influences the mechanical properties of the entitled perovskites, leading to higher ductility and anisotropy. As a whole, this study offers insights into the scientific applications of non-toxic perovskites in different pressure environments.
本研究的目的是通过使用 ab initio 方法研究 ABI3（A = Rb、Cs；B = Ca、Sr）金属卤化物包晶的结构、电子、光学和机械特性，从而提高其在多种技术应用中的利用率。在常压下，RbCaI3、RbSrI3、CsCaI3 和 CsSrI3 的几何优化晶格常数分别为 6.19 Å、6.45 Å、6.22 Å 和 6.47 Å，与之前的研究结果一致。此外，还观察到晶格参数和键长明显减少，从而导致原子相互作用水平增加。压力缩小了从紫外区到可见区的带隙。这一现象促进了电子从价带向导带的转移，从而提高了光电设备的性能。此外，施加压力会使带隙从间接带隙转变为直接带隙，从而提高材料在光伏应用中的适用性。利用电荷密度图确定了 Ca/Sr-I 和 Rb/Cs-I 在有压和无压条件下的共价和离子性质。增强的压力大大提高了可见光谱的光吸收和电导率，这意味着在提高包晶体太阳能电池和光子器件的功效方面具有巨大的潜力。此外，施加的压力还能极大地影响有权利的包晶石的机械性能，从而提高延展性和各向异性。总之，这项研究为无毒包晶石在不同压力环境下的科学应用提供了启示。
{"title":"Indirect to direct band gap transition of ABI3 (A = Rb, Cs; B = Ca, Sr) perovskites under hydrostatic pressure for photovoltaic and optoelectronic applications: A DFT study","authors":"","doi":"10.1016/j.physb.2024.416538","DOIUrl":"10.1016/j.physb.2024.416538","url":null,"abstract":"<div><div>The objective of this study is to enhance the utilization of ABI<sub>3</sub> (A = Rb, Cs; B = Ca, Sr) metal-halide perovskites in multiple forms of technological applications by investigating their structural, electronic, optical, and mechanical characteristics using the ab initio method. At ambient pressure, the geometry-optimized lattice constants for RbCaI<sub>3</sub>, RbSrI<sub>3</sub>, CsCaI<sub>3</sub>, and CsSrI<sub>3</sub> are 6.19 Å, 6.45 Å, 6.22 Å, and 6.47 Å, respectively, consistent with prior research. Additionally, a significant decrease in lattice parameters and bond length is observed, which leads to increased levels of atomic interactions. Pressure narrows the band gap from the ultraviolet-to-visible region. This phenomenon promotes the transfer of electrons from the valence-to-conduction band, hence improving the performance of optoelectronic devices. Furthermore, a shift from an indirect to a direct band gap is induced by the application of pressure, which improves the material's suitability for photovoltaic applications. The covalent and ionic nature of Ca/Sr-I and Rb/Cs-I under pressure and without pressure conditions was determined using the charge density maps. Enhanced pressure significantly boosts optical absorption and conductivity in the visible spectrum, implying substantial potential for improving the efficacy of perovskite solar cells and photonic devices. Additionally, applied pressure significantly influences the mechanical properties of the entitled perovskites, leading to higher ductility and anisotropy. As a whole, this study offers insights into the scientific applications of non-toxic perovskites in different pressure environments.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315205","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 : 2024-09-21DOI: 10.1016/j.physb.2024.416560
Broadband dielectric spectroscopy studies of the two-phase composites, (1 – x) Co3O4 + x Co2TiO4, have been reported over a wide range of compositions (0 ≤ x ≤ 1) and temperatures (80 K ≤ T ≤ 573 K). Normal spinel Co3O4 and inverse spinel Co2TiO4 phases are well distinguishable with ∼4.6 % variation in the lattice parameter of the Co3O4 phase with an increase of x from 0 to x = 1. The ac-conductivity (σ) of this composite follows Johnscher's power law (∼Aωs) variation with frequency exponent factor ‘s’ both greater than as well as less than unity. The temperature dependence of ‘σ’ reveals the Arrhenius-like behavior instead of variable range hopping of charge carriers with activation energy in the 2–1800 meV range. Systematic analysis of such conductivity mechanisms for all the compositions is compared with the pristine Co3O4 system.
对两相复合材料（(1 - x) Co3O4 + x Co2TiO4）进行了宽带介电光谱研究，研究范围包括成分（0 ≤ x ≤ 1）和温度（80 K ≤ T ≤ 573 K）。正尖晶石 Co3O4 和反尖晶石 Co2TiO4 可很好地区分，随着 x 值从 0 增加到 x = 1，Co3O4 相的晶格参数变化了 4.6%。这种复合材料的交流电导率（σ）随着频率指数因子 "s "的增大和减小而呈现约翰舍尔幂律（∼Aωs）变化。σ "的温度依赖性揭示了类似阿伦尼乌斯的行为，而不是活化能在 2-1800 meV 范围内的电荷载流子的可变范围跳跃。对所有成分的这种传导机制的系统分析与原始 Co3O4 系统进行了比较。
{"title":"Broadband dielectric spectroscopy studies of Co3O4 and Co2TiO4 two-phase spinel composites","authors":"","doi":"10.1016/j.physb.2024.416560","DOIUrl":"10.1016/j.physb.2024.416560","url":null,"abstract":"<div><div>Broadband dielectric spectroscopy studies of the two-phase composites, (1 – <em>x</em>) Co<sub>3</sub>O<sub>4</sub> + <em>x</em> Co<sub>2</sub>TiO<sub>4,</sub> have been reported over a wide range of compositions (0 ≤ <em>x</em> ≤ 1) and temperatures (80 K ≤ T ≤ 573 K). Normal spinel Co<sub>3</sub>O<sub>4</sub> and inverse spinel Co<sub>2</sub>TiO<sub>4</sub> phases are well distinguishable with ∼4.6 % variation in the lattice parameter of the Co<sub>3</sub>O<sub>4</sub> phase with an increase of <em>x</em> from 0 to <em>x</em> = 1. The ac-conductivity (σ) of this composite follows Johnscher's power law (∼Aω<sup>s</sup>) variation with frequency exponent factor ‘s’ both greater than as well as less than unity. The temperature dependence of ‘σ’ reveals the Arrhenius-like behavior instead of variable range hopping of charge carriers with activation energy in the 2–1800 meV range. Systematic analysis of such conductivity mechanisms for all the compositions is compared with the pristine Co<sub>3</sub>O<sub>4</sub> system.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326748","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 : 2024-09-21DOI: 10.1016/j.physb.2024.416563
Our research examines the electronic thermal conductivity, electrical conductivity, Seebeck coefficient, and figure of merit of the α-T3 structure utilizing the Green's function approach within the Hamiltonian framework of the Kane-Mele (KM) and Hubbard models. We evaluate how variations in chemical potential, on-site Coulomb repulsion (OSCR) strength, and spin-orbit coupling (SOC) parameters influence these properties. Our findings uncover interesting trends: the presence of a flat band at the energy level of zero within this structure and the gap between the flat band and other bands is observed. The observable rise in SOC results in a clear division within the energy band, demonstrating the notable impact SOC exerts on the electronic structure of the system.Moreover, this strategy displays that this material's thermoelectric properties increase due to temperature, SOC, and OSCR. Also, it was observed that augmenting the α parameter can enhance both thermoelectric and thermopower.
{"title":"Improving thermoelectric performance of α−T3 structure via integration of the Kane-Mele-Hubbard model","authors":"","doi":"10.1016/j.physb.2024.416563","DOIUrl":"10.1016/j.physb.2024.416563","url":null,"abstract":"<div><div>Our research examines the electronic thermal conductivity, electrical conductivity, Seebeck coefficient, and figure of merit of the α-T<sub>3</sub> structure utilizing the Green's function approach within the Hamiltonian framework of the Kane-Mele (KM) and Hubbard models. We evaluate how variations in chemical potential, on-site Coulomb repulsion (OSCR) strength, and spin-orbit coupling (SOC) parameters influence these properties. Our findings uncover interesting trends: the presence of a flat band at the energy level of zero within this structure and the gap between the flat band and other bands is observed. The observable rise in SOC results in a clear division within the energy band, demonstrating the notable impact SOC exerts on the electronic structure of the system.Moreover, this strategy displays that this material's thermoelectric properties increase due to temperature, SOC, and OSCR. Also, it was observed that augmenting the α parameter can enhance both thermoelectric and thermopower.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315109","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 : 2024-09-20DOI: 10.1016/j.physb.2024.416559
The bulk pristine CuCrO2, doped CuCr0.96M0.03V0.01O2 (M = Ti, Mn, Ga and Nb), CuCr0.96V0.04O2, CuCr0.97Mg0.03O2, CuCr0.97Ni0.03O2, and CuCr1-xFexO2 (x = 0.03, 0.06, and 0.09) compounds with single rhombohedral phase were investigated through low-temperature dc resistivity, field-dependent magnetization, and dielectric measurements. The room-temperature UV measurements were also carried out to determine possible changes in the optical bandgap due to the dopants mentioned above. The present work provides significant evidence of novel methodology for optimizing the number of localized carrier holes along with a reduction in helical disorder around MO6 octahedra, which leads to enhancement of the double exchange along the Cr-O-M-O linkages or superexchange between M3+/4+-Cr3+ mediated via oxygen. The nonmagnetic substitution in magnetic sublattice disrupts the spin spiral and a net weak component is realized in magnetization measurements.
{"title":"Enhancement of multiferrocity in CuCrO2 compounds through effective doping induced optimization of localized carrier holes and reduction in helical disorder","authors":"","doi":"10.1016/j.physb.2024.416559","DOIUrl":"10.1016/j.physb.2024.416559","url":null,"abstract":"<div><p>The bulk pristine CuCrO<sub>2</sub>, doped CuCr<sub>0.96</sub>M<sub>0.03</sub>V<sub>0.01</sub>O<sub>2</sub> (M = Ti, Mn, Ga and Nb), CuCr<sub>0.96</sub>V<sub>0.04</sub>O<sub>2</sub>, CuCr<sub>0.97</sub>Mg<sub>0.03</sub>O<sub>2</sub>, CuCr<sub>0.97</sub>Ni<sub>0.03</sub>O<sub>2</sub>, and CuCr<sub>1-<em>x</em></sub>Fe<sub><em>x</em></sub>O<sub>2</sub> (<em>x</em> = 0.03, 0.06, and 0.09) compounds with single rhombohedral phase were investigated through low-temperature dc resistivity, field-dependent magnetization, and dielectric measurements. The room-temperature UV measurements were also carried out to determine possible changes in the optical bandgap due to the dopants mentioned above. The present work provides significant evidence of novel methodology for optimizing the number of localized carrier holes along with a reduction in helical disorder around MO<sub>6</sub> octahedra, which leads to enhancement of the double exchange along the Cr-O-M-O linkages or superexchange between M<sup>3+/4+</sup>-Cr<sup>3+</sup> mediated via oxygen. The nonmagnetic substitution in magnetic sublattice disrupts the spin spiral and a net weak component is realized in magnetization measurements.</p></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142270327","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 : 2024-09-20DOI: 10.1016/j.physb.2024.416553
A systematic study was undertaken to analyze the electronic and thermal properties of a single electron within a superelliptic quantum ring under orthogonal magnetic and electric fields. The corresponding Schrödinger equation for this system was numerically solved using the finite element method within the effective mass approximation. The influence of geometric effects associated with the morphology of the inner and outer contours of the superellipse, as well as the impact of external fields on electronic and thermal properties, were analyzed. The flexibility of the superellipse shape parameters considered in this study allows the consideration of different types of rings and the derivation of several electronic properties previously published in the literature as particular cases of our model. It was observed that thermal properties are highly sensitive to external fields and the geometrical potential linked to the topological variations experienced by the superellipse during the growth of the quantum rings.
{"title":"Superelliptic quantum rings under orthogonally applied electric and magnetic fields: Electronic and thermal properties","authors":"","doi":"10.1016/j.physb.2024.416553","DOIUrl":"10.1016/j.physb.2024.416553","url":null,"abstract":"<div><div>A systematic study was undertaken to analyze the electronic and thermal properties of a single electron within a superelliptic quantum ring under orthogonal magnetic and electric fields. The corresponding Schrödinger equation for this system was numerically solved using the finite element method within the effective mass approximation. The influence of geometric effects associated with the morphology of the inner and outer contours of the superellipse, as well as the impact of external fields on electronic and thermal properties, were analyzed. The flexibility of the superellipse shape parameters considered in this study allows the consideration of different types of rings and the derivation of several electronic properties previously published in the literature as particular cases of our model. It was observed that thermal properties are highly sensitive to external fields and the geometrical potential linked to the topological variations experienced by the superellipse during the growth of the quantum rings.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319614","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}
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