Materials Today Quantum最新文献

Quantum metric non-linear Hall effect in an antiferromagnetic topological insulator thin-film EuSn2As2

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

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

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

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

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

Microwave-assisted synthesis of sulfur-doped carbon quantum dots and their application in logic gate operations

Materials Today Quantum Pub Date : 2024-12-17 DOI: 10.1016/j.mtquan.2024.100021

Lijun Liu , Xiangru Hou , Lu Ga , Yanqing Du , Jun Ai , Gerile Aodeng

引用次数: 0

Tutorial: Extracting entanglement signatures from neutron spectroscopy

Materials Today Quantum Pub Date : 2024-12-16 DOI: 10.1016/j.mtquan.2024.100020

Allen Scheie , Pontus Laurell , Wolfgang Simeth , Elbio Dagotto , D. Alan Tennant

引用次数: 0

Conversion between dipoles with different spatial parities by circularly polarized light

Materials Today Quantum Pub Date : 2024-12-12 DOI: 10.1016/j.mtquan.2024.100019

Satoru Hayami

引用次数: 0

Topological magnetic defects in a strong permanent magnet Nd2Fe14B 强永磁体 Nd2Fe14B 中的拓扑磁性缺陷

Materials Today Quantum Pub Date : 2024-10-09 DOI: 10.1016/j.mtquan.2024.100017

Juyoung Jeong , Yongwoo Lee , Shi-Zeng Lin , Yoon Hee Jeong , Hye Jung Chang , Jeehoon Kim

引用次数: 0

Synthesis of temperature-sensitive boron, nitrogen and sulphur doped carbon dots and their applications 温度敏感的硼、氮和硫掺杂碳点的合成及其应用

Materials Today Quantum Pub Date : 2024-10-04 DOI: 10.1016/j.mtquan.2024.100018

Pingping Liu , Lu Fu , Gerile Aodeng , Lu Ga , Jun Ai

引用次数: 0