Journal of Physics: Condensed Matter最新文献

{"title":"Correlation of Dirac ordering with optical activity in AlB₂-type Dirac MBenes.","authors":"Ashish Sharma","doi":"10.1088/1361-648X/adc3e4","DOIUrl":"https://doi.org/10.1088/1361-648X/adc3e4","url":null,"abstract":"<p><p>Using first-principles calculations, this study systematically investigates the electronic properties and optical activity of AlB$_2$-type Dirac MBenes alongwith their correlations. Insights from phonon-spectral calculations and textit{ab-initio} molecular dynamics simulations substantiates the thermally and dynamically stable character of Dirac MBenes. Electronic dispersions reveals that all Dirac MBenes exhibits finitely gapped Dirac cones at the fermi level, while FeB$_2$ MBene behaves as a zero-band-gap semimetal akin to graphene. Such gap in Dirac cones is desirable and crucial for optoelectronic applications. The interplay of out-of-plane $d_{xz}$ and $d_{yz}$ orbitals of metal atom and hybrids in-plane d$_{xy}$ and d$_{x^2-y^2}$ orbitals from metal atom with p orbitals from boron atoms can be attributed to the emergence of Dirac cones in MBenes. The calculations clearly reveal that the static dielectric constant and the energy gap within the Dirac cones are critical factors influencing the electron-hole screening effect, consequently effecting the exciton binding energy. Further, it has been demonstrated that the exciton binding energies are consistent with predictions made by the two-dimensional Mott-Wannier model, confirming the Mott-Wannier characteristics of excitons in AlB$_2$-type Dirac MBenes, with the exception of partial Frenkel character in FeB$_2$ MBene. Furthermore, it is demonstrated that Dirac MBenes exhibit a significant light absorption capacity in the near-infrared (NIR) and visible regions, with electron-hole interactions slightly modifying the optical spectral profile, making them promising for optoelectronic and photovoltaic applications. Subsequently, covariance analysis indicates that moderate energy gaps and high static dielectric constants are conducive to hosting Mott-Wannier excitons. Additionally, careful control of d-state valence electrons and hole doping can regulate the Mott-Wannier and Frenkel character of excitons in 2D Dirac materials. Thus, this comprehensive and systematic analysis of the electronic properties and optical-excitonic behavior of AlB$_2$-type Dirac MBenes, alongwith their correlations, enhances our understanding of this emerging family of two-dimensional materials.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143673329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Superconductivity in metal sulfides.","authors":"Wei Zhong, He Zhang, Fang Hong, Binbin Yue","doi":"10.1088/1361-648X/adbe1c","DOIUrl":"10.1088/1361-648X/adbe1c","url":null,"abstract":"<p><p>The exploration of high-temperature superconductors and the mechanisms underlying superconductivity continues to present significant challenges in condensed matter physics. Identifying new potential superconducting (SC) platforms is critical for advancing our understanding of superconductivity and its interactions with other quantum states. Metal sulfides constitute a diverse family of materials that exhibit unique physical properties, with crystal structures that can be tailored from one-dimensional (1D) to three-dimensional (3D) by varying the metal-to-sulfur ratio. Recent investigations into the superconductivity of metal sulfides have revealed extraordinary quantum phenomena, including chiral superconductivity, two-dimensional (2D) Ising superconductivity, and the competition between charge density waves and superconductivity. Furthermore, pressure tuning-a refined technique for modifying electronic and crystal structures without introducing impurities-has facilitated the emergence of superconductivity in various semiconducting and even insulating metal sulfides. In this review, we summarize and analyze the rich SC properties of metal sulfides, encompassing 3D metal monosulfides, 2D metal disulfides, and quasi-1D transition metal trisulfides. We also discuss additional systems, including hydrogen sulfides, Th₃P₄-type sulfides, and Bi-S systems. Collectively, these findings underscore that metal sulfides not only represent promising SC materials but also serve as excellent platforms for further investigation into the mechanisms of superconductivity.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Magnetic structure of Mn₂GaC thin film by neutron scattering.","authors":"Quanzheng Tao, Aurelija Mockute, Fabio Orlandi, Dmitry Khalyavin, Pascal Manuel, Gunnar Palsson, Bachir Ouladdiaf, Johanna Rosen, Andrew T Boothroyd","doi":"10.1088/1361-648X/adbece","DOIUrl":"10.1088/1361-648X/adbece","url":null,"abstract":"<p><p>MAX phases are a family of atomically laminated materials with various potential applications. Mn₂GaC is a prototype magnetic MAX phase, where complex magnetic behaviour arises due to competing interactions. We have resolved the room temperature magnetic structure of Mn₂GaC by neutron diffraction from single-crystal thin films and we propose a magnetic model for the low temperature phase. It orders in a helical structure, with a rotation angle that changes gradually between 120° and 90° depending on temperature.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143597160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Role of electron-electron interaction in the Mpemba effect in quantum dots.","authors":"Juliane Graf, Janine Splettstoesser, Juliette Monsel","doi":"10.1088/1361-648X/adc3e3","DOIUrl":"https://doi.org/10.1088/1361-648X/adc3e3","url":null,"abstract":"<p><p>The Mpemba effect has initially been noticed in macroscopic systems-namely that hot water can freeze faster than cold water-but recently its extension to open quantum systems has attracted significant attention. This phenomenon can be explained in the context of nonequilibrium thermodynamics of Markovian systems, relying on the amplitudes of different decay modes of the system dynamics. Here, we study the Mpemba effect in a single-level quantum dot coupled to a thermal bath, highlighting the role of the sign and magnitude of the electron-electron interaction in the occurrence of the Mpemba effect. We gain physical insights into the decay modes from a dissipative symmetry of this system called fermionic duality. Based on this analysis of the relaxation to equilibrium of the dot, we derive criteria for the occurrence of the Mpemba effect using two thermodynamically relevant measures of the distance to equilibrium, the nonequilibrium free energy and the dot energy. We furthermore compare this effect to a possible exponential speedup of the relaxation. Finally, we propose experimentally relevant schemes for the state preparation and explore different ways of observing the Mpemba effect in quantum dots in experiments.&#xD.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143673440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Field-free Josephson diode effect in interacting chiral quantum dot junctions.","authors":"Debika Debnath, Paramita Dutta","doi":"10.1088/1361-648X/adbeaf","DOIUrl":"10.1088/1361-648X/adbeaf","url":null,"abstract":"<p><p>We investigate chiral quantum dot (QD)-based Josephson junction and show the correlation-induced Josephson diode effect (JDE) in it. The presence of electron-electron interaction spontaneously creates an imbalance between up- and down-spin electrons during the non-equilibrium transport making the QD effectively magnetic. The simultaneous presence of the chirality and the interaction eventually results in the field-free JDE in our chiral QD junction. We employ the Keldysh non-equilibrium Green's function technique to study the behavior of the Josephson current and the rectification coefficient (RC) of our Josephson diode (JD). We show a sign-changing behavior of the RC with the Coulomb correlation and the lead-to-dot coupling strength and find the maximum magnitude of the RC∼72%for moderate interaction strength. Our proposed field-free JD based on interacting chiral QD may be a potential switching component in superconductor based devices.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143597158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Topologically protected magnetic structures in perforated multilayer films.","authors":"Magadeev Eugene Borisovich, Ratmir Rimovich Nugumanov, Sharafullin Ildus Fanisovich","doi":"10.1088/1361-648X/adbcef","DOIUrl":"10.1088/1361-648X/adbcef","url":null,"abstract":"<p><p>The paper theoretically studies thin ferromagnetic films obtained by successive deposition of layers of easy-axis and easy-plane materials. It is shown that in films of this type, under certain conditions, effective anisotropy can arise, leading to the appearance of new directions of easy magnetization, set of which is divided into two independent orbits. The structure of domain walls (DWs) arising as a result of the transition of the magnetization vector from one orbit to another was studied. It has been proven that in the presence of perforations in the films under consideration, topologically protected inhomogeneities can arise, which are localized in the vicinity of two closely spaced holes and can be in one of six nonequivalent states, as a result of which paired perforations can be considered as memory cells for recording data in a base 6 number system. A numerical experiment has demonstrated that two adjacent cells can actually independently encode two digits in the specified number system due to the possibility of forming thin DWs between the cells.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143567494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Structural chirality and related properties in periodic inorganic solids: review and perspectives.","authors":"Eric Bousquet, Mauro Fava, Zachary Romestan, Fernando Gómez-Ortiz, Emma E McCabe, Aldo H Romero","doi":"10.1088/1361-648X/adb674","DOIUrl":"10.1088/1361-648X/adb674","url":null,"abstract":"<p><p>Chirality refers to the asymmetry of objects that cannot be superimposed on their mirror image. It is a concept that exists in various scientific fields and has profound consequences. Although these are perhaps most widely recognized within biology, chemistry, and pharmacology, recent advances in chiral phonons, topological systems, crystal enantiomorphic materials, and magneto-chiral materials have brought this topic to the forefront of condensed matter physics research. Our review discusses the symmetry requirements and the features associated with structural chirality in inorganic materials. This allows us to explore the nature of phase transitions in these systems, the coupling between order parameters, and their impact on the material's physical properties. We highlight essential contributions to the field, particularly recent progress in the study of chiral phonons, altermagnetism, magnetochirality between others. Despite the rarity of naturally occurring inorganic chiral crystals, this review also highlights a significant knowledge gap, presenting challenges and opportunities for structural chirality mostly at the fundamental level, e.g. chiral displacive phase transitions, possibilities of tuning and switching structural chirality by external means (electric, magnetic, or strain fields), whether chirality could be an independent order parameter, and whether structural chirality could be quantified, etc. Beyond simply summarizing this field of research, this review aims to inspire further research in materials science by addressing future challenges, encouraging the exploration of chirality beyond traditional boundaries, and seeking the development of innovative materials with superior or new properties.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143425542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Particle Acceleration During Classical Phase Transitions on a Spherical Lattice.","authors":"Aidan Bachmann, Pierre Gourdain, Eric G Blackman","doi":"10.1088/1361-648X/adc0d7","DOIUrl":"https://doi.org/10.1088/1361-648X/adc0d7","url":null,"abstract":"<p><p>When compressed, certain lattices undergo phase transitions that may allow nuclei to gain sig-&#xD;nificant kinetic energy. To explore the dynamics of this phenomenon, we develop a methodology&#xD;to study Coulomb coupled N-body systems constrained to a sphere, as in the Thomson problem.&#xD;We initialize N total Boron nuclei as point particles on the surface of the sphere, allowing them to&#xD;equilibrate via Coulomb scattering with a viscous damping term. To simulate a phase transition,&#xD;we remove Nrm particles, forcing the system to rearrange into a new equilibrium. With this model,&#xD;we consider the Thomson problem as a dynamical system, providing a framework to explore how&#xD;non-zero temperature affects structural imperfections in Thomson minima. We develop a scaling&#xD;relation for the average peak kinetic energy attained by a single particle as a function of N and&#xD;Nrm. For certain values of N , we find an order of magnitude energy gain when increasing Nrm from&#xD;1 to 6. The model may help to design a lattice that maximizes the energy output.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143630369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Multi-cation synergy improves crystallization and antioxidation of CsSnBr₃for lead-free perovskite light-emitting diodes.","authors":"Jie Wang, Dongyuan Han, Huiyu Ji, Ziang Zang, Jianheng Zhou, Ning Wang","doi":"10.1088/1361-648X/adb823","DOIUrl":"10.1088/1361-648X/adb823","url":null,"abstract":"<p><p>Tin (Sn) perovskites have emerged as promising alternatives to address the toxicity concerns associated with lead-based (Pb) perovskite light-emitting diodes (PeLEDs). However, the inherent oxidation of Sn perovskite films leads to a serious efficiency roll-off in PeLEDs at increased current densities. Although three-dimensional CsSnBr₃perovskites exhibit decent carrier mobilities and thermal stability, their rapid crystallization during solution processing results in inadequate surface coverage. This inadequate coverage increases non-radiative recombination and leakage current, thereby hindering Sn PeLED performance. Herein, we present a multi-cation synergistic strategy by introducing the organic cations formamidinium (FA⁺) and thiophene ethylamine (TEA⁺) into CsSnBr₃perovskites. The addition of organic cations delays crystallization by forming hydrogen bonds interacting with the CsSnBr₃. The smaller FA⁺enters the perovskite lattice and improves crystallinity, while the larger TEA⁺cation enhances surface coverage and passivates defect states. By further optimizing the interface between PEDOT:PSS and perovskite layers through the use of ethanolamine and a thin layer of LiF, we achieved a red Sn-based PeLED with an emission wavelength of 670 nm, a maximum luminance of 151 cd m^-2, and an external quantum efficiency of 0.21%.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143458407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 anomalous temperature dependent low energy electron diffraction intensity at epitaxial Sr₃Ir₂O₇thin film surfaces.","authors":"Peace Ikeoluwa Adegbite, Arjun Subedi, Yuanyuan Zhang, Xia Hong, Takashi Komesu, P A Dowben","doi":"10.1088/1361-648X/adbaa8","DOIUrl":"10.1088/1361-648X/adbaa8","url":null,"abstract":"<p><p>We report on the temperature dependent low energy electron diffraction (LEED) studies of 12 nm epitaxial Sr₃Ir₂O₇(001) thin films. The Debye temperature has been extracted from the temperature-dependence of LEED intensity at elevated temperatures and different electron kinetic energies. For the most surface sensitive LEED, obtained at the lowest electron kinetic energies, the extracted surface Debye temperature is 270 ± 22 K, which is much lower than the 488 ± 40 K Debye temperature obtained using higher electron kinetic energies. Surprisingly, the LEED diffraction intensity, at the lowest electron kinetic energies, increases rather than decreases, with increasing sample temperatures up to about 440 K. This anomalous behavior has been attributed to the reduction of the lattice vibrational amplitudes along the surface normal. This damping of the normal mode vibrations with increasing temperature results from the enhanced electronic screening via thermally activated carriers. This scenario is corroborated by the transport measurement, showing that Sr₃Ir₂O₇is a narrow band Mott insulator with a band gap of about 32 meV. We have identified criteria for finding anomalous scattering behavior in other transition metal oxide systems.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143515789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}