Materials Today Quantum最新文献_第2页

Contrasting character of Cr and Mn solitary dopants in CdTe CdTe中Cr和Mn孤立掺杂物的对比特性

Materials Today Quantum Pub Date : 2025-03-18 DOI: 10.1016/j.mtquan.2025.100032

Sameer Gupta, Damien Caliste, Pascal Pochet

{"title":"Contrasting character of Cr and Mn solitary dopants in CdTe","authors":"Sameer Gupta, Damien Caliste, 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}

引用次数: 0

Quantum Heisenberg spin chains in reconstructed armchair graphene nanoribbons towards ballistic quantum spin transport 重建扶手椅石墨烯纳米带中量子海森堡自旋链的弹道量子自旋输运

Materials Today Quantum Pub Date : 2025-03-01 DOI: 10.1016/j.mtquan.2025.100028

Ning Wu , Bang-Gui Liu

引用次数: 0

Compensation doping of the qubit host Ba2CaWO6-δ 量子比特主体Ba2CaWO6-δ的补偿掺杂

Materials Today Quantum Pub Date : 2025-03-01 DOI: 10.1016/j.mtquan.2025.100029

Abby N. Neill , Lucas A. Pressley , Tyrel M. McQueen

{"title":"Compensation doping of the qubit host Ba2CaWO6-δ","authors":"Abby N. Neill , Lucas A. Pressley , 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 W<sup>5+</sup> centers in the double perovskite Ba<sub>2</sub>CaWO<sub>6-δ</sub>, here we report on the viability of compensation doping with Zr<sup>4+</sup> and Ge<sup>4+</sup> to tune the number of active W<sup>5+</sup> centers, a pre-requisite for mitigating spin bath effects and increasing spin-spin relaxation times. We prepared single crystals of nominal composition Ba<sub>2</sub>CaW<sub>1-x</sub>M<sub>x</sub>O<sub>6-δ</sub> (M = Zr<sup>4+</sup>, Ge<sup>4+</sup>) 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 = Zr<sup>4+</sup>) and x = 0.03 (M = Ge<sup>4+</sup>) are sufficient to quench the W<sup>5+</sup> 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 Ba<sub>2</sub>CaWO<sub>6-δ</sub> 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}

引用次数: 0

An overview on metal-doped carbon dots uses for biomedical applications 金属掺杂碳点在生物医学上的应用综述

Materials Today Quantum Pub Date : 2025-03-01 DOI: 10.1016/j.mtquan.2025.100030

Miriam Ala , Claudia Suriano , Mattia Bartoli , Alberto Tagliaferro

引用次数: 0

Programming an optical lattice interferometer 光栅干涉仪编程

Materials Today Quantum Pub Date : 2025-03-01 DOI: 10.1016/j.mtquan.2025.100026

Lennart Maximilian Seifert , Victor E. Colussi , Michael A. Perlin , Pranav Gokhale , Frederic T. Chong

{"title":"Programming an optical lattice interferometer","authors":"Lennart Maximilian Seifert , Victor E. Colussi , Michael A. Perlin , Pranav Gokhale , 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}

引用次数: 0

Quantum metric non-linear Hall effect in an antiferromagnetic topological insulator thin-film EuSn2As2 反铁磁拓扑绝缘体薄膜EuSn2As2的量子度量非线性霍尔效应

Materials Today Quantum Pub Date : 2025-02-17 DOI: 10.1016/j.mtquan.2025.100027

Hung-Ju Tien , Hsin Lin , Liang Fu , Tay-Rong Chang

{"title":"Quantum metric non-linear Hall effect in an antiferromagnetic topological insulator thin-film EuSn2As2","authors":"Hung-Ju Tien , Hsin Lin , Liang Fu , 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}

引用次数: 0

Damping enhancement in YIG at millikelvin temperatures due to GGG substrate GGG衬底在毫开尔文温度下对YIG的阻尼增强

Materials Today Quantum Pub Date : 2025-02-05 DOI: 10.1016/j.mtquan.2025.100025

Rostyslav O. Serha , Andrey A. Voronov , David Schmoll , Rebecca Klingbeil , Sebastian Knauer , Sabri Koraltan , Ekaterina Pribytova , Morris Lindner , Timmy Reimann , Carsten Dubs , Claas Abert , Roman Verba , Michal Urbánek , Dieter Suess , Andrii V. Chumak

{"title":"Damping enhancement in YIG at millikelvin temperatures due to GGG substrate","authors":"Rostyslav O. Serha , Andrey A. Voronov , David Schmoll , Rebecca Klingbeil , Sebastian Knauer , Sabri Koraltan , Ekaterina Pribytova , Morris Lindner , Timmy Reimann , Carsten Dubs , Claas Abert , Roman Verba , Michal Urbánek , Dieter Suess , 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 50K poses a challenge for quantum applications. Here, we study the damping in a 97nm-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 30mK 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 18GHz and temperatures below 2K and frequencies above 10GHz, 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}

引用次数: 0

Determination of band alignment of core/shell colloidal CdSe/CdS quantum dots, by optical and X-ray photo-electron spectroscopies 用光学和x射线光电子能谱法测定核/壳胶体CdSe/CdS量子点的能带排列

Materials Today Quantum Pub Date : 2025-01-30 DOI: 10.1016/j.mtquan.2025.100024

Damien Simonot , Céline Roux-Byl , Xiangzhen Xu , Willy Daney de Marcillac , Corentin Dabard , Mathieu G. Silly , Emmanuel Lhuillier , Thomas Pons , Simon Huppert , Agnès Maître

{"title":"Determination of band alignment of core/shell colloidal CdSe/CdS quantum dots, by optical and X-ray photo-electron spectroscopies","authors":"Damien Simonot , Céline Roux-Byl , Xiangzhen Xu , Willy Daney de Marcillac , Corentin Dabard , Mathieu G. Silly , Emmanuel Lhuillier , Thomas Pons , Simon Huppert , Agnès Maître","doi":"10.1016/j.mtquan.2025.100024","DOIUrl":"10.1016/j.mtquan.2025.100024","url":null,"abstract":"<div><div>Optical properties of multilayer semi-conductor nano-emitters are crucially dependent on the relative energy levels of their different components. For core/shell quantum dots, the relative energy difference between conduction band edge of core and shell materials induces, depending on its value, either a confinement of the electron within the core or a delocalization of its wave function within the whole quantum dot. This results in drastic consequences on the energy and the oscillator strength of the transitions. Surprisingly, the literature currently lacks a definitive value for this energy difference, called offset, between the conduction band edge of CdSe and CdS materials. Here, we develop a theoretical model expressing energy levels and considering quantum dot dimension, core/shell interface pressure, ligands and allowing to reliably determine the conduction band offset. Its value is determined experimentally using our model and both optical and X-ray photoelectron (XPS) spectroscopies.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"5 ","pages":"Article 100024"},"PeriodicalIF":0.0,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182482","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}

引用次数: 0

Towards dissipationless topotronics 走向无耗散地形学

Materials Today Quantum Pub Date : 2025-01-16 DOI: 10.1016/j.mtquan.2025.100023

Qing Yan , Hailong Li , Hua Jiang , X.C. Xie

{"title":"Towards dissipationless topotronics","authors":"Qing Yan , Hailong Li , Hua Jiang , X.C. Xie","doi":"10.1016/j.mtquan.2025.100023","DOIUrl":"10.1016/j.mtquan.2025.100023","url":null,"abstract":"<div><div>Many aspects of topological physics offer a promising paradigm for the development of dissipationless electronic and quantum computing devices. Topological materials exhibit quantized transport and unidirectional edge states, which are inherently robust against backscattering and were thus previously assumed to be dissipationless. However, recent advancements in nanoscale thermal imaging have uncovered localized heat generation in these materials, highlighting an urgent need to reassess energy dissipation issues in topological systems. In this Perspective, we review recent progress in understanding energy dissipation in topological systems, including experimental observations enabled by pioneering thermal imaging techniques and theoretically proposed mechanisms. Central to this discussion is the recognition that energy dissipation arises from the evolution of carriers' energy distribution, independent of quantized electrical signatures. We discuss emerging criteria to identify dissipationless topological devices, providing guidance for the design of next-generation topotronics. Finally, we outline future directions, including the exploration of additional degrees of freedom, superconducting regimes, and non-Abelian operations, as well as the advancement of measurement techniques and scalable manufacturing processes, and especially emphasizing the importance of experimental verification of theoretical mechanisms.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"5 ","pages":"Article 100023"},"PeriodicalIF":0.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182481","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}

引用次数: 0

Linear and nonlinear Edelstein effects in chiral topological semimetals 手性拓扑半金属中的线性和非线性Edelstein效应

Materials Today Quantum Pub Date : 2025-01-01 DOI: 10.1016/j.mtquan.2024.100022

Haowei Xu , Ju Li

{"title":"Linear and nonlinear Edelstein effects in chiral topological semimetals","authors":"Haowei Xu , Ju Li","doi":"10.1016/j.mtquan.2024.100022","DOIUrl":"10.1016/j.mtquan.2024.100022","url":null,"abstract":"<div><div>Recently, there has been growing interest in achieving on-demand control of magnetism through electrical and optical means. In this work, we provide first-principles predictions for the linear and nonlinear Edelstein effects (LEE and NLEE) in the chiral topological semimetal CoSi. The LEE and NLEE represent first- and second-order magnetic responses to external electric fields, enabling precise manipulation of magnetization via electrical and optical methods. We demonstrate that although both LEE and NLEE require time-reversal symmetry breaking, they can still be realized in non-magnetic materials, as time-reversal symmetry can be spontaneously broken by heat and dissipation, according to the second law of thermodynamics. Meanwhile, due to different inversion symmetry selection rules, the LEE and NLEE manifest opposite and identical signs in the two enantiomers of CoSi, respectively. We further quantify the magnitude of LEE and NLEE, showing that electrically or optically induced magnetization can reach 10 Bohr magneton per unit cell when the external electric field strength is comparable with the internal atomic electric field, which is on the order of 1 V/Å. Our work offers a systematical approach for predicting the electrical and optical control of magnetism in real materials, paving the way for potential applications in areas such as spintronics and magnetic memories.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"5 ","pages":"Article 100022"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182480","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}

引用次数: 0