Materials Today Quantum最新文献

{"title":"First-principles prediction of anisotropic superconductivity in the nodal-line semi-metal TlTaSe2","authors":"Mukhtar Lawan Adam ,&nbsp;Ibrahim Buba Garba ,&nbsp;Sulaiman Muhammad Gana ,&nbsp;Bala Ismail Adamu ,&nbsp;Abba Alhaji Bala ,&nbsp;Abdulsalam Aji Suleiman ,&nbsp;Ahmad Hamisu ,&nbsp;Tijjani Hassan Darma ,&nbsp;Auwal Musa ,&nbsp;Abdulkadir S. Gidado","doi":"10.1016/j.mtquan.2025.100037","DOIUrl":"10.1016/j.mtquan.2025.100037","url":null,"abstract":"<div><div>Recent advances in topological quantum materials have spurred significant interest in exploring superconductors that also host nontrivial band topology, as these materials can serve as platforms for novel electronic phases and quantum technologies. TlTaSe₂ is one such non-centrosymmetric, quasi-two-dimensional semimetal with nodal-line topological features protected by mirror-reflection symmetry. In this study, we theoretically predict its superconducting properties using first-principles anisotropic Migdal–Eliashberg theory. Our results indicate that the states at the Fermi, are primarily Ta 5d and Tl 6p orbitals. Thus, exhibiting a multiband electronic structure. Notably, from our calculations, we find two distinct superconducting gaps of 2.15 meV and 4.5 meV on different Fermi surface sheets, arising from strongly anisotropic electron-phonon interactions predominantly involving in-plane vibrations of the Ta and Tl atoms. Using the Allen–Dynes-modified McMillan formula with a Coulomb pseudopotential μ* = 0.16, we predict a superconducting transition temperature Tc of 6.67 K. These findings underscore the significance of TlTaSe₂ as a candidate for topological superconductivity and provide insights into how the interplay between anisotropy, electron-phonon coupling, and nontrivial band topology can be explored for quantum computing and spintronics applications.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"6 ","pages":"Article 100037"},"PeriodicalIF":0.0,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrafast dynamics and tunable coherent optical phonons via hybridization and gold layering in hybrid topological Bi2Se1.5Te1.5","authors":"Prince Sharma ,&nbsp;Rahul Sharma ,&nbsp;Saurabh Saini ,&nbsp;Kapil Kumar ,&nbsp;Sumeet Walia ,&nbsp;Mahesh Kumar","doi":"10.1016/j.mtquan.2025.100035","DOIUrl":"10.1016/j.mtquan.2025.100035","url":null,"abstract":"<div><div>Topological insulators (TIs) are quantum materials that offer exotic optoelectronic, magnetic, and spintronic properties and lead to numerous applications such as quantum computing, Majorana Fermions, superconductivity, terahertz frequency generation, spintronics, thermoelectricity, and optoelectronics. TIs are inherently insulating in bulk, but, the topologically active surface states offer free electrons on the surfaces to enable them to be conducted on the surface. However, binary tetradymites (Bi₂Se₃, Bi₂Te₃, and Sb₂Te₃) are not fully insulating in bulk due to their semiconducting characteristics. To overcome this behaviour, the pure TIs can be converted to a new class of hybrid topological insulators (HTI) via doping. In this article, we present a detailed analysis of such kinds of HTI Bi₂Se_1.5Te_1.5 by examining their symmetry, band structure, charge carrier and phonon dynamics. Unlike pure TIs, this HTI possesses distinct optical properties, which are explored in this study. Additionally, a 15 nm gold film is deposited on TIs (Bi₂Se₃ and Bi₂Te₃) and HTI (Bi₂Se_1.5Te_1.5) crystal flakes to investigate the interaction between gold (Au) plasmonic coupling with these materials using transient reflectance spectroscopy. The main goal of Au is to tune the optical response of TIs through the plasmonic effect of Au. Besides carrier dynamics, the study also examines coherent acoustic and optical phonons in Bi₂Se₃, Bi₂Te₃ and Bi₂Se_1.5Te_1.5 as well as along with Au layered micro flakes. The hybrid Bi₂Se_1.5Te_1.5 topological material and gold layering introduce new opportunities for optoelectronics and spintronics, offering broad tunability in various optical and near-infrared regions.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"6 ","pages":"Article 100035"},"PeriodicalIF":0.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strongly confined Te quantum dots as building blocks for single photon sources","authors":"Rajendra Subedi ,&nbsp;Francisco Ruiz-Zepeda ,&nbsp;Yagya Bahadur Woli ,&nbsp;Thang Ba Hoang ,&nbsp;Julien Chaste ,&nbsp;Etienne Herth ,&nbsp;Grégory Guisbiers","doi":"10.1016/j.mtquan.2025.100034","DOIUrl":"10.1016/j.mtquan.2025.100034","url":null,"abstract":"<div><div>Tellurium is a heavy chemical element exhibiting chirality, anisotropy, and strong spin-orbit coupling; consequently, displaying a huge potential in quantum hardware technologies. In this article, tellurium quantum dots, with sizes around 19 ± 3 nm and energy bandgap around 2.4 eV, were successfully synthesized by pulsed laser ablation in liquids (PLAL). The synthesis was performed by using a nanosecond Nd:YAG laser emitting at 1064 nm and pulsing the laser beam at 1 kHz. Toluene (C₆H₅CH₃) was used as a solvent to avoid oxidation of the dots. Non-polarized and polarized Raman spectroscopy as well as X-Ray diffraction were performed on the dots to study their quantum confinement and anisotropy. Finally, strongly confined tellurium quantum dots were obtained; and, their properties underline their potential as quantum light sources.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"6 ","pages":"Article 100034"},"PeriodicalIF":0.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contrasting character of Cr and Mn solitary dopants in CdTe","authors":"Sameer Gupta,&nbsp;Damien Caliste,&nbsp;Pascal Pochet","doi":"10.1016/j.mtquan.2025.100032","DOIUrl":"10.1016/j.mtquan.2025.100032","url":null,"abstract":"<div><div>Solitary dopants or single impurities embedded in semiconductor matrix having unique magnetic and optical properties are emerging as a promising platform to realize novel quantum devices. The realization of such devices however requires an atomic level control over the growth of such quantum defects to establish reproducible and scalable defect creation strategies. Among the solitary dopants, transition metal doped in semiconductor quantum dots are particularly interesting due to the ease of optical spin addressability. In this article we have investigated the challenges associated with embedding magnetic impurities, considering the case of single Mn and Cr dopants in the CdTe lattice. Optical control of single spin of such magnetic impurities trapped in a CdTe quantum dot has already been reported. We show using the first principle based calculations that the interactions with CdTe intrinsic defects poses challenges to the growth of single Cr and Mn trapped in a CdTe nanostructure. We provide a detailed thermodynamic analysis establishing that control over the growth process to embed a single Mn in CdTe, can be achieved without significant challenge but remains elusive in the case of Cr. Interestingly, some of the defect complexes resulting from the interaction of the metal dopant and intrinsic defects present the possibility to control and manipulate the spin and oxidation state of the impurity in the complex configuration. These defect complexes opens up the possibility of tuning optical and magnetic properties of single TM dopants. Finally, we propose guidelines and defect engineering strategies to mitigate or on the contrary to select the creation of such complexes.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"6 ","pages":"Article 100032"},"PeriodicalIF":0.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum Heisenberg spin chains in reconstructed armchair graphene nanoribbons towards ballistic quantum spin transport","authors":"Ning Wu ,&nbsp;Bang-Gui Liu","doi":"10.1016/j.mtquan.2025.100028","DOIUrl":"10.1016/j.mtquan.2025.100028","url":null,"abstract":"<div><div>It is well-known that ferromagnetism can be realized along a pristine zigzag graphene nanoribbon edge (ZGNE), but the pristine armchair graphene nanoribbon edge (AGNE) is nonmagnetic. Here, we achieve Heisenberg antiferromagnetic (AFM) spin chains through reconstruction of the AGNEs. The reconstructed edge consists of pentagonal carbon rings or a hybrid of pentagonal and hexagonal carbon rings, and its total energy per carbon atom (indicating stability) is between those of AGNE and ZGNE. The resultant nanoribbons are narrow-gap semiconductors and their band-edge states are either nonmagnetic bulk states or spin-degenerate real-space edge states due to the reconstructed edges. The spin is located on the outermost carbon of the pentagonal ring, and the inter-spin exchange is the nearest-neighbor AFM interaction. For finite chain length or nonzero magnetization, there are nonzero spin Drude weights and thus ballistic quantum spin transport can be achieved along the reconstructed edges. These could be useful for graphene-related quantum spin information and spintronics applications.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"5 ","pages":"Article 100028"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compensation doping of the qubit host Ba2CaWO6-δ","authors":"Abby N. Neill ,&nbsp;Lucas A. Pressley ,&nbsp;Tyrel M. McQueen","doi":"10.1016/j.mtquan.2025.100029","DOIUrl":"10.1016/j.mtquan.2025.100029","url":null,"abstract":"<div><div>Emerging quantum information science (QIS) technologies require advances in controlling the type, number, and distribution of defects in complex crystalline matter. Building on recent reports of promising spin-lattice relaxation times in oxygen-vacancy-induced W⁵⁺ centers in the double perovskite Ba₂CaWO_6-δ, here we report on the viability of compensation doping with Zr⁴⁺ and Ge⁴⁺ to tune the number of active W⁵⁺ centers, a pre-requisite for mitigating spin bath effects and increasing spin-spin relaxation times. We prepared single crystals of nominal composition Ba₂CaW_1-xM_xO_6-δ (M = Zr⁴⁺, Ge⁴⁺) for x = 0–0.20. Electron paramagnetic resonance (EPR) and DC magnetic susceptibility measurements were used to understand the changes in spin-active defects as a function of substitution. We find that x = 0.01 (M = Zr⁴⁺) and x = 0.03 (M = Ge⁴⁺) are sufficient to quench the W⁵⁺ S = ½ EPR response (g = 2.00) within our limit of detection. Further substitution results in the appearance of a narrow S = ½ response (g = 1.98–2.00) that fades away at higher compositions. We conclude that compensation doping is an effective strategy for modulation of single ion centers in Ba₂CaWO_6-δ and identify future steps that are needed to bring such complex materials to viability for QIS technologies, including proposal of an easily measured figure of merit for rapid materials iteration and optimization.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"5 ","pages":"Article 100029"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An overview on metal-doped carbon dots uses for biomedical applications","authors":"Miriam Ala ,&nbsp;Claudia Suriano ,&nbsp;Mattia Bartoli ,&nbsp;Alberto Tagliaferro","doi":"10.1016/j.mtquan.2025.100030","DOIUrl":"10.1016/j.mtquan.2025.100030","url":null,"abstract":"<div><div>Metal-based drugs are of capital relevance for the modern medical chemistry. Nonetheless, their use has faced several issues related to toxicity and scarce biocompatibility. Metal-doped carbon dots can represent an interesting and promising solution for simultaneously exploiting the properties of metal-based drugs together with the superior biocompatibility, solubility, and photoluminescent properties of pristine carbon dots. In this concise review, we discussed the utilization of metal-doped carbon dots in biomedical applications with a focus on chemotherapy and diagnostic uses.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"5 ","pages":"Article 100030"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Programming an optical lattice interferometer","authors":"Lennart Maximilian Seifert ,&nbsp;Victor E. Colussi ,&nbsp;Michael A. Perlin ,&nbsp;Pranav Gokhale ,&nbsp;Frederic T. Chong","doi":"10.1016/j.mtquan.2025.100026","DOIUrl":"10.1016/j.mtquan.2025.100026","url":null,"abstract":"<div><div>Programming a quantum device describes the usage of quantum logic gates, agnostic of hardware specifics, to perform a sequence of operations with (typically) a computing or sensing task in mind. Such programs have been executed on gate-based quantum computers, which despite their noisy character, have shown the ability to optimize metrological functions, for example in the generation of spin squeezing and optimization of quantum Fisher information for signals manifesting as spin rotations in a quantum register. However, the qubits of these programmable quantum sensors are tightly spatially confined and therefore suboptimal for enclosing the kinds of large spacetime areas required for performing inertial sensing. In this work, we derive a set of quantum logic gates for a cold atom optical lattice interferometer that manipulates the momentum of atoms. Here, the operations are framed in terms of single qubit operations and mappings between qubit subspaces with internal levels given by the Bloch (crystal) eigenstates of the lattice. We describe how the quantum optimal control method of direct collocation is well suited for obtaining modulation waveforms of an optical lattice to achieve these operations in existing experimental setups.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"5 ","pages":"Article 100026"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum metric non-linear Hall effect in an antiferromagnetic topological insulator thin-film EuSn2As2","authors":"Hung-Ju Tien ,&nbsp;Hsin Lin ,&nbsp;Liang Fu ,&nbsp;Tay-Rong Chang","doi":"10.1016/j.mtquan.2025.100027","DOIUrl":"10.1016/j.mtquan.2025.100027","url":null,"abstract":"<div><div>The quantum geometric structure of electrons introduces fundamental insights into understanding quantum effects in materials. One notable manifestation is the non-linear Hall effect (NLHE), which has drawn considerable interest for its potential to overcome the intrinsic limitations of semiconductor diodes at low input power and high frequency. In this study, we investigate NLHE stemming from the real part of the quantum geometric tensor, specifically the quantum metric, in an antiferromagnetic topological material, EuSn<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, using density functional theory. Our calculations predict a remarkable NLHE arising from a symmetry-protected, single Type-II surface Dirac cone in the even-numbered-layer two-dimensional slab thin-film, yielding a non-linear Hall conductivity exceeding 20 mA/V<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span>—an order of magnitude larger than previously reported. This single Dirac band dispersion represents the simplest model for generating NLHE, positioning the EuSn<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> thin-film as a “hydrogen atom” for NLHE systems. Additionally, we observe NLHE from band-edge states near the Fermi level. Our findings also reveal that 30% phosphorus (P) doping can double the non-linear Hall conductivity. With its substantial and tunable NLHE, EuSn<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> thin-films present promising applications in antiferromagnetic spintronics and rectification devices.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"5 ","pages":"Article 100027"},"PeriodicalIF":0.0,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Damping enhancement in YIG at millikelvin temperatures due to GGG substrate","authors":"Rostyslav O. Serha ,&nbsp;Andrey A. Voronov ,&nbsp;David Schmoll ,&nbsp;Rebecca Klingbeil ,&nbsp;Sebastian Knauer ,&nbsp;Sabri Koraltan ,&nbsp;Ekaterina Pribytova ,&nbsp;Morris Lindner ,&nbsp;Timmy Reimann ,&nbsp;Carsten Dubs ,&nbsp;Claas Abert ,&nbsp;Roman Verba ,&nbsp;Michal Urbánek ,&nbsp;Dieter Suess ,&nbsp;Andrii V. Chumak","doi":"10.1016/j.mtquan.2025.100025","DOIUrl":"10.1016/j.mtquan.2025.100025","url":null,"abstract":"<div><div>Quantum magnonics aims to exploit the quantum mechanical properties of magnons for nanoscale quantum information technologies. Ferrimagnetic yttrium iron garnet (YIG), which offers the longest magnon lifetimes, is a key material typically grown on gadolinium gallium garnet (GGG) substrates for structural compatibility. However, the increased magnetic damping in YIG/GGG systems below 50<!--> <!-->K poses a challenge for quantum applications. Here, we study the damping in a 97<!--> <!-->nm-thick YIG film on a <span><math><mrow><mn>500</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>-thick GGG substrate at temperatures down to 30<!--> <!-->mK using ferromagnetic resonance (FMR) spectroscopy. We show that the dominant physical mechanism for the observed tenfold increase in FMR linewidth at millikelvin temperatures is the non-uniform bias magnetic field generated by the partially magnetized paramagnetic GGG substrate. Numerical simulations and analytical theory show that the GGG-driven linewidth enhancement can reach up to 6.7 times. In addition, at low temperatures and frequencies above 18<!--> <!-->GHz and temperatures below 2<!--> <!-->K and frequencies above 10<!--> <!-->GHz, the FMR linewidth deviates from the viscous Gilbert-damping model. These results allow the partial elimination of the damping mechanisms attributed to GGG, which is necessary for the advancement of solid-state quantum technologies.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"5 ","pages":"Article 100025"},"PeriodicalIF":0.0,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}