Article
Chemistry, Multidisciplinary
Junheng Ou, Qingtian Zhang
Summary: We investigated spin-dependent thermoelectric transport in zigzag phosphorene nanoribbons with a ferromagnetic stripe. We explored the possibility to enhance the spin thermopower via modifications of the edge states in zigzag ribbons. Two methods are proposed to modulate the edge transport: one is applying gate voltages on the edges; the other is including notches on the ribbon edges. The transport gap is enlarged by the edge-state modifications, which enhance the charge and spin Seebeck coefficients almost twofold.
Article
Chemistry, Physical
Ziqi Han, Hua Hao, Xiaohong Zheng, Zhi Zeng
Summary: In this study, the spin-dependent transport properties of zigzag graphene nanoribbons (ZGNR) with asymmetric edge hydrogenation and different magnetic configurations were investigated using the non-equilibrium Green's function method combined with density functional calculations. The results showed that changing the magnetic configurations of the electrodes from parallel to antiparallel resulted in substantial changes in the currents in the tunnel junction, leading to a high conductance state and a low conductance state with a tunnel magnetoresistance (TMR) ratio larger than 1 x 10(5)%. Furthermore, an ideal bipolar spin filtering effect was observed in the parallel magnetic configurations, allowing for flexible switching of the spin polarity of current by reversing the bias direction. These findings indicate that asymmetric edge hydrogenation provides an important approach for constructing multi-functional spintronic devices with ZGNRs.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Ankit Sirohi, Jawar Singh
Summary: In this study, the structural stability, magnetic properties, and thermoelectric properties of Mn-passivated armchair silicene nanoribbons (Mn-ASiNRs) were investigated using density functional theory. It was found that all structures studied were thermodynamically stable and exhibited ferromagnetic ground states with a Curie temperature above 400 K. The electronic properties of Mn-ASiNRs were found to be dependent on their width (N), with 4-, 5-, and 7-Mn-ASiNRs being semiconducting, 6-Mn-ASiNR being half-metallic, and 8-Mn-ASiNR being metallic. Furthermore, simulations of Mn-ASiNR-based devices showed enhanced thermoelectric properties, including high spin Seebeck coefficient (Ss) and charge Seebeck coefficient (Sc), as well as improved charge and spin thermoelectric figures of merit (ZcT and ZsT) compared to pristine nanoribbons (H-ASiNRs).
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2023)
Article
Physics, Condensed Matter
Lingling Song, Zhihong Yang, Lu Liu, Liwei Yuan, Han Zhao, Xing Chen, Yan Zhang, Xiaohong Zheng
Summary: This study found that edge dihydrogenation in zigzag silicene nanoribbons can be tuned to be half-metallic, with a significantly increased FM-AFM energy difference compared to edge monohydrogenation. The observed half-metallicity originates from the different potentials between the two edges of the ribbon after doping, resulting in opposite shifts in energy for the edge states of the two spin channels.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Nanoscience & Nanotechnology
Dan-Dan Wu, Hua-Hua Fu
Summary: The study uncovers several exotic thermal spin-related transport properties of the narrowest zigzag graphene nanoribbons, including thermal colossal magnetoresistance effect, thermal negative differential resistance effect, spin-Seebeck effect, and spin-filtering effect, pushing carbon-based material candidates towards thermoelectric conversion device applications.
Article
Chemistry, Multidisciplinary
Jinfan Shao, Erjun Kan, Yan Qian, Haiping Wu
Summary: Two-dimensional intrinsic silicon nanosheets were assembled from zigzag silicene nanoribbons with different widths using first-principles theory, and it was found that all the nanosheets behaved as semiconductors. In a certain strain range, the nanosheets exhibited a negative Poisson's ratio. This study provides a new approach to design semiconducting silicon nanosheets.
Article
Physics, Multidisciplinary
Jing-Fen Zhao, Hui Wang, Zai-Fa Yang, Hui Gao, Hong-Xia Bu, Xiao-Juan Yuan
Summary: Exploring silicon-based spin modulating junction is a promising area of spintronics. In this study, a set of spin filters of hydrogenated zigzag silicene nanoribbons is designed by substituting a silicon atom with a boron one, and the spin-correlated transport properties are studied. The results show that spin polarization can be achieved by structural symmetry breaking induced by boron doping. Moreover, by tuning the edge hydrogenation, the efficiency of the spin filter can be varied, and it is also found that asymmetric hydrogenation can lead to negative differential resistance.
Article
Physics, Applied
Jintao Xu, Mingjun Li, Qian Wang, Xiaojiao Zhang, Jiajia Fei, Yuechao Shi, Bei Zhang, Meng-Qiu Long
Summary: The spin caloritronics of zigzag blue phosphorus nanoribbons with edge hydrogenation and oxidation were studied. The results show that perfect thermal spin filtering effect and negative differential thermoelectric resistance can be observed in structures with oxidized and hydrogenated edges, while these features were not found in structures with hydrogenated edges. Furthermore, the edge oxygen atoms in the nanoribbons offer different transport pathways for spin-up and spin-down states, leading to thermal spin filtering effect.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Physics, Condensed Matter
Van-Chinh Ngo, Thi-Kim-Quyen Nguyen, Nguyen-Huu-Hanh Pham, Tu-Huynh Pham, Thi-Kim-Loan Phan, Van-Nam Do, Thanh-Tra Vu
Summary: In this study, we investigate the influence of divacancies on the electronic structure and thermoelectric properties of zigzag buckling silicene nanoribbons. We find that the metallic nature of the nanoribbons is retained even in the presence of divacancies. Introducing divacancies can enhance the conductivity of the nanoribbons, and an applied electric field leads to a linear increase in the band gap width and Seebeck coefficient.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Multidisciplinary Sciences
Raymond E. Blackwell, Fangzhou Zhao, Erin Brooks, Junmian Zhu, Ilya Piskun, Shenkai Wang, Aidan Delgado, Yea-Lee Lee, Steven G. Louie, Felix R. Fischer
Summary: Spin-ordered electronic states in hydrogen-terminated zigzag nanographene lead to magnetic quantum phenomena, sparking interest in carbon-based spintronics. Zigzag graphene nanoribbons have intrinsic electronic edge states that are ferromagnetically ordered along the edges and antiferromagnetically coupled across its width. By introducing substitutional N-atom dopants along the edges of a ZGNR, the spin-polarized edge states can be stabilized and electronically decoupled, revealing a giant spin splitting and confirming the emergence of magnetic order in ZGNRs.
Article
Materials Science, Multidisciplinary
Fereshte Ildarabadi, Rouhollah Farghadan
Summary: We investigated the edge magnetism of zigzag-edge silicene-like nanoribbons under non-uniform linear strain, focusing on the intrinsic spin-orbit coupling. Our findings revealed that band-splitting and spin-polarized states can be induced by applied non-uniform strain, even when intrinsic magnetism is absent. Additionally, different edge magnetizations were observed under the influence of non-uniform strain. Moreover, we discovered that the Hubbard interaction can enhance the strain effect and create an ideal condition for valley-based transport by inducing valley asymmetry.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
A. Garcia-Fuente, D. Carrascal, G. Ross, J. Ferrer
Summary: Finite-length armchair graphene nanoribbons can exhibit one-dimensional topological properties with edge states, depending on their width and termination. We provide a complete solution for tight-binding graphene rectangles of any length and width, which can be seen as either finite-length armchair or zigzag ribbons. We derive exact expressions for the bulk and edge eigenstates and eigenenergies. We also investigate the Coulomb interactions among edge states and analyze the emergence and characteristics of different magnetic states at the edges using a Hubbard-dimer model.
Article
Materials Science, Multidisciplinary
Suejeong You, Daehan Park, Heesang Kim, Nammee Kim
Summary: By studying the electronic structure and quantum transport of a zigzag monolayer molybdenum disulfide nanoribbon, it has been found that spin-selective transport can be achieved and spin filters can be constructed using implanted nanoribbons.
CURRENT APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Xingyi Tan, Xuelian Xu, Linjie Ding, Yelu He
Summary: The study found that zigzag alpha-graphyne nanoribbons undergo a transformation from indirect-band-gap bipolar magnetic semiconductors into half-metallic materials as the parameter N increases. Two spin caloritronics devices based on representative N = 4 and N = 12 alpha-graphene nanoribbons were designed, showing linear and nonlinear thermal spin transport properties in the former and only linear properties in the latter. These findings suggest that alpha-graphyne nanoribbons are potential candidates for spin caloritronics device applications.
CHEMICAL PHYSICS LETTERS
(2021)
Article
Physics, Applied
Lingling Song, Lu Liu, Canglong Wei, Yan Zhang, Han Zhao, Runlong Ye, Xiaohong Zheng
Summary: Investigated the spin-polarized transport properties of a device with a vacuum barrier sandwiched between two ferromagnetic graphene nanoribbons. Found robust spin polarization and giant magnetoresistance in the device, and demonstrated the generation of spin-polarized photocurrent under polarized light illumination.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)