Engineering Papers⌕ Search
Home/Archive/DOE OSTI

DOE OSTI · 2933700

Direct observation of distinct bulk and edge nonequilibrium spin accumulation in ultrathin MoTe 2

Chen, Fangchu [Univ. of Waterloo, ON (Canada)]·Das, Kamal [Weizmann Institute of Science, Rehovot (Israel)] (ORCID:0000000339717693)·Yang, Bowen [Univ. of Waterloo, ON (Canada)] (ORCID:0009000184562427)·Wang, Chuangtang [Univ. of Michigan, Ann Arbor, MI (United States)]·Zhong, Shazhou [Univ. of Waterloo, ON (Canada)] (ORCID:0000000151384866)·Golovanova, Diana [Weizmann Institute of Science, Rehovot (Israel)]·Ren, He [Univ. of Waterloo, ON (Canada)]·Wang, Tianyang [Chinese Academy of Sciences (CAS) (China); Univ. of Science and Technology of China, Hefei (China)]·Luo, Xuan [Chinese Academy of Sciences (CAS) (China)] (ORCID:0000000204824096)·Sun, Yuping [Chinese Academy of Sciences (CAS) (China); Nanjing Univ. (China)] (ORCID:000000032477285X)·Zhao, Liuyan [Univ. of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000195123537)·Miao, Guo-Xing [Univ. of Waterloo, ON (Canada)] (ORCID:0000000243545540)·Yan, Binghai [Weizmann Institute of Science, Rehovot (Israel); Pennsylvania State Univ., University Park, PA (United States)] (ORCID:0000000321645839)·Tsen, Adam W. [Univ. of Waterloo, ON (Canada)] (ORCID:0000000343563308)
View original source ↗Read source document ↗Export metadata ↓

Abstract

Low-symmetry two-dimensional (2D) topological materials such as MoTe 2 host efficient charge-to-spin conversion (CSC) mechanisms that can be harnessed for novel electronic and spintronic devices. However, the nature of the various CSC mechanisms and their correlation with underlying crystal symmetries remain unsettled. In this work, we use local spin-sensitive electrochemical potential measurements to directly probe the spatially dependent nonequilibrium spin accumulation in MoTe 2 flakes down to four atomic layers. We are able to clearly disentangle contributions originating from the spin Hall and Rashba-Edelstein effects and uncover an abundance of unconventional spin polarizations that develop uniquely in the sample bulk and edges with decreasing thickness. Using ab-initio calculations, we construct a unified understanding of all the observed CSC components in relation to the material dimensionality and stacking arrangement. Our findings not only illuminate previous CSC results on MoTe 2 but also have important ramifications for future devices that can exploit the local and layer-dependent spin properties of this 2D topological material.

Explore related subjects

Science & Technology - Other Topicselectronic properties and materialsspintronicstwo-dimensional materials

Keep this discovery

BibTeXRIS

Chen, Fangchu [Univ. of Waterloo, ON (Canada)], Das, Kamal [Weizmann Institute of Science, Rehovot (Israel)] (ORCID:0000000339717693), Yang, Bowen [Univ. of Waterloo, ON (Canada)] (ORCID:0009000184562427), Wang, Chuangtang [Univ. of Michigan, Ann Arbor, MI (United States)], Zhong, Shazhou [Univ. of Waterloo, ON (Canada)] (ORCID:0000000151384866), Golovanova, Diana [Weizmann Institute of Science, Rehovot (Israel)], Ren, He [Univ. of Waterloo, ON (Canada)], Wang, Tianyang [Chinese Academy of Sciences (CAS) (China); Univ. of Science and Technology of China, Hefei (China)], Luo, Xuan [Chinese Academy of Sciences (CAS) (China)] (ORCID:0000000204824096), Sun, Yuping [Chinese Academy of Sciences (CAS) (China); Nanjing Univ. (China)] (ORCID:000000032477285X), Zhao, Liuyan [Univ. of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000195123537), Miao, Guo-Xing [Univ. of Waterloo, ON (Canada)] (ORCID:0000000243545540), Yan, Binghai [Weizmann Institute of Science, Rehovot (Israel); Pennsylvania State Univ., University Park, PA (United States)] (ORCID:0000000321645839), Tsen, Adam W. [Univ. of Waterloo, ON (Canada)] (ORCID:0000000343563308). 2025-07-03. Direct observation of distinct bulk and edge nonequilibrium spin accumulation in ultrathin MoTe 2. https://doi.org/10.1038/s41467-025-61550-2

Cite the original work for its findings. Save a collection to share your selection of sources.

Discover connections

Science & Technology - Other Topics subjectSpintronics subjectTwo-dimensional materials subjectelectronic properties and materials subject

Connections use source metadata and explicit phrase matches, not verified experimental comparisons.

KEEP EXPLORING

Related reports

DOE OSTI2024

Pressure induced modification of electronic and magnetic properties of MnCrNbAl and MnCrTaAl

Spin-gapless semiconductor (SGS) is a new class of material that has been studied recently for potential applications in spintronics. This material behaves as an insulator for one spin channel, and as a gapless semiconductor for the opposite spin. In this work, we present results of a computational study of two quaternary Heusler alloys, MnCrNbAl and MnCrTaAl that have been recently reported to exhibit spin-gapless semiconducting electronic structure. In particular, using density functional calculations we analyze the effect of external pressure on electronic and magnetic properties of these compounds. It is shown that while these two alloys exhibit nearly SGS behavior at optimal lattice constants and at negative pressure (expansion), they are half-metals at equilibrium, and magnetic semiconductors at larger lattice constant. At the same time, reduction of the unit cell volume has a detrimental effect on electronic properties of these materials, by modifying the exchange splitting of their electronic structure and ultimately destroying their half-metallic/semiconducting behavior. Thus, our results indicate that both MnCrNbAl and MnCrTaAl may be attractive for practical device applications in spin-based electronics, but a potential compression of the unit cell volume (e.g. in thin-film applications) should be avoided.

Materials Science↗
DOE OSTI2025

Linear Dichroism of the Optical Properties of SnS and SnSe Van der Waals Crystals

Abstract Tin monochalcogenides SnS and SnSe, belonging to a family of Van der Waals crystals isoelectronic to black phosphorus, are known as environmentally friendly materials promising for thermoelectric conversion applications. However, they exhibit other desired functionalities, such as intrinsic linear dichroism of the optical and electronic properties originating from strongly anisotropic orthorhombic crystal structures. This property makes them perfect candidates for polarization‐sensitive photodetectors working in near‐infrared spectral range. A comprehensive study of the SnS and SnSe crystals is presented, performed by means of optical spectroscopy and photoemission spectroscopy, supported by ab initio calculations. The studies reveal the high sensitivity of the optical response of both materials to the incident light polarization, which is interpreted in terms of the electronic band dispersion and orbital composition of the electronic bands, dictating the selection rules. From the photoemission investigation the ionization potential, electron affinity and work function are determined, which are parameters crucial for the design of devices based on semiconductor heterostructures.

Chemistry↗
DOE OSTI2024

From wide to ultrawide-bandgap semiconductors for high power and high frequency electronic devices

Abstract Wide and ultrawide-bandgap (U/WBG) materials have garnered significant attention within the semiconductor device community due to their potential to enhance device performance through their substantial bandgap properties. These exceptional material characteristics can enable more robust and efficient devices, particularly in scenarios involving high power, high frequency, and extreme environmental conditions. Despite the promising outlook, the physics of UWBG materials remains inadequately understood, leading to a notable gap between theoretical predictions and experimental device behavior. To address this knowledge gap and pinpoint areas where further research can have the most significant impact, this review provides an overview of the progress and limitations in U/WBG materials. The review commences by discussing Gallium Nitride, a more mature WBG material that serves as a foundation for establishing fundamental concepts and addressing associated challenges. Subsequently, the focus shifts to the examination of various UWBG materials, including AlGaN/AlN, Diamond, and Ga 2 O 3 . For each of these materials, the review delves into their unique properties, growth methods, and current state-of-the-art devices, with a primary emphasis on their applications in power and radio-frequency electronics.

Materials Science↗