Article
Chemistry, Physical
Liwen Zhang, Jun Chen, Lei Zhang, Fuming Xu, Liantuan Xiao, Suotang Jia
Summary: Graphene with micrometer spin relaxation length presents promising potential in spintronics, but efficient spin injection remains a challenge. Generating spin current in ZGNR via photogalvanic effect provides a novel approach to achieve spin injection without accompanying charge current, and the spin current generation and polarization can be controlled through a dual gate system.
Article
Chemistry, Physical
Wen-Tao Fu, Peng Zhao, Gang Chen
Summary: In this study, the spin-polarized transport properties of an all-carbon molecular device were investigated using first-principles density functional theory and the nonequilibrium Green's function methodology. The results demonstrate the realization of giant magnetoresistance and spin-rectifying effects in the device under external magnetic field modulation.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Chemistry, Multidisciplinary
James Lawrence, Alejandro Berdonces-Layunta, Shayan Edalatmanesh, Jesus Castro-Esteban, Tao Wang, Alejandro Jimenez-Martin, Bruno de la Torre, Rodrigo Castrillo-Bodero, Paula Angulo-Portugal, Mohammed S. G. Mohammed, Adam Matej, Manuel Vilas-Varela, Frederik Schiller, Martina Corso, Pavel Jelinek, Diego Pena, Dimas G. de Oteyza
Summary: This study demonstrates two chemical protection/deprotection strategies for chiral graphene nanoribbons, allowing them to survive exposure to air and regain their original electronic properties through hydrogenation and annealing.
Article
Multidisciplinary Sciences
Dongfei Wang, De-Liang Bao, Qi Zheng, Chang-Tian Wang, Shiyong Wang, Peng Fan, Shantanu Mishra, Lei Tao, Yao Xiao, Li Huang, Xinliang Feng, Klaus Muellen, Yu-Yang Zhang, Roman Fasel, Pascal Ruffieux, Shixuan Du, Hong-Jun Gao
Summary: Stacking layered materials with nonzero interlayer twist angles, such as graphene and transitional metal dichalcogenides, has attracted attention due to their novel physical properties. In this study, we demonstrate that the edge states of twisted bilayer zigzag graphene nanoribbons (TBZGNRs) can be tuned by both the twist angle and the stacking offset. Strong edge state variations in the stacking region are revealed by density functional theory (DFT) calculations and scanning tunneling microscopy. Our work highlights the fundamental differences between 2D and 1D twistronics and encourages further investigation of twisted one-dimensional systems.
NATURE COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
M. Sankush Krishna, Sangeeta Singh
Summary: Quantum coherence and non-equilibrium statistics play a key role in electronic transport in 2-D materials. This study explores the electronic transport properties of pristine and N-doped disconnected zigzag ZnO nanoribbons, revealing that even disconnected structures can exhibit electron transport. N-dopant position affects the I-V characteristics, with the highest NDR peak-to-valley current ratio reported around 5.6 x 104.
MICROELECTRONICS JOURNAL
(2021)
Article
Multidisciplinary Sciences
Young Heon Kim, Hye Jeong Lee, Hyun-Yong Lee, S-R Eric Yang
Summary: Interacting disordered zigzag nanoribbons at low doping exhibit a new disordered anyon phase with e(-) /2 fractional charges, leading to spin-charge separation and non-local correlation. Experimental predictions include the replacement of soft gap by sharp peaks in tunneling density of states, and the disappearance of midgap peak with increasing doping concentration. Further investigations may reveal unusual transport, magnetic, and inter-edge tunneling properties in doped zigzag ribbons.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Physical
Yuejun Li, Xiaofei Shang, Yan-Hong Zhou, Xiaohong Zheng
Summary: In this study, we investigated the photogalvanic effect of a zigzag graphene nanoribbon junction with a centro-symmetrical structure composed of 8 zigzag chains using density functional calculations. Specifically, we focused on the variation of spin-dependent photocurrents when the irradiated region is partially located in the central region. It was found that the magnitude of spin-dependent photocurrents increased with the size of the irradiated region, and pure spin current was only achieved when the entire central region was irradiated. Additionally, we examined the additive effect in this device and found that the sum of spin currents generated by irradiating two separate parts of the central region was smaller than that obtained by irradiating the whole central region, indicating the importance of coupling effect in photocurrent generation.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Multidisciplinary Sciences
Jie Zhang, Eric P. Fahrenthold
Summary: Research has focused on the spin current transmission properties of narrow zigzag graphene nanoribbons (zGNRs), exploring methods such as doping, functionalization, edge modification, and external electric fields for spin current control. Recent studies have shown that narrow antiferromagnetic zGNRs exhibit distinct current transmission characteristics compared to their ferromagnetic counterparts, with effects such as negative differential resistance and spatially periodic electron transport structures.
SCIENTIFIC REPORTS
(2021)
Article
Physics, Multidisciplinary
Ming Li, Zi-Liang Cai, Zhi-Bo Feng, Zheng-Yin Zhao
Summary: This study investigates the valley-resolved transport properties of zigzag graphene nanoribbon (ZGNR) junctions using the transfer matrix and Green's function methods. It is found that by adjusting the width of ZGNRs, the valley polarization efficiency and transmission coefficients can be controlled, which has potential applications in manipulating carrier transport properties at ZGNR junctions.
COMMUNICATIONS IN THEORETICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Mandar Jatkar, Kamal K. Jha, Sarat K. Patra
Summary: By investigating Zigzag GaN nanoribbons using DFT and NEGF framework, the study found that Fe doping can enhance the structural stability of ZGaNNR and the magnetic moment of different configurations depends on the position of Fe atom. Fe-termination@N_edge ZGaNNR is considered a strong candidate for magnetic stabilization, while Fe-termination@both_the_edges ZGaNNR exhibits high metallicity.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Physics, Condensed Matter
Xiao-Dong Tan, Le Cui, Ya-Feng Song
Summary: In a zigzag graphene nanoribbon thermalized with a reservoir at temperature T, entanglement dynamics between two edge spins display oscillating behaviors in the presence of an external magnetic field. The oscillations strongly depend on the field frequency and relative location between spins. At critical field frequencies, the entanglement shows a periodic structure. Regular and symmetrical oscillating patterns occur at low temperatures, while irregular distortions appear at high temperatures due to thermal fluctuations. Even at room temperature, entanglement between two edge spins in ZGNR still maintains a nontrivial value.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Chemistry, Physical
Ziyang Wei, Philippe Sautet
Summary: The understanding of the chemical properties of zigzag edge terminated graphene nanoribbons (ZGNRs) is important for practical applications. This study investigates the energy differences between the ferromagnetic (FM) and antiferromagnetic (AFM) states of ZGNRs and proposes a refinement to the partial radical concept. The findings suggest that the AFM state is more stable than the nonmagnetic (NM) state and lead to changes in the predicted reactivity of ZGNR models.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Fei Gao, Rodrigo E. E. Menchon, Aran Garcia-Lekue, Mads Brandbyge
Summary: Recently, researchers have combined porphyrin units with graphene nanoribbons (Por-GNR) to create various structures. In this study, the authors use first-principles calculations to investigate the properties of two experimentally feasible Por-GNR hybrids. They find that one of the hybrids has a small band gap and can be used as electrodes in devices. By embedding a Fe atom in the porphyrin, a spin-polarized ground state is achieved. The authors examine the spin transport properties of a 2-terminal setup involving a Fe-Por-GNR between Por-GNR electrodes and observe a Fano anti-resonance feature. They also demonstrate how mechanical strain or chemical adsorption can induce spin-crossover, leading to different spin states. These findings provide valuable insights for the development of carbon-based spintronics and chemical sensing applications.
COMMUNICATIONS PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Yuejun Li, Hua Hao, Xiaofei Shang, Yan-Hong Zhou, Xiaohong Zheng
Summary: We utilize first-principles calculations to construct zigzag graphene nanoribbon junctions, generating pure spin current through the photogalvanic effect (PGE). Two devices with spatial inversion symmetry are designed, both consisting of three zigzag graphene nanoribbons (ZGNRs) that introduce either two carbon tetragons (2-C4) or two carbon hexagons (2-C6) as connectors. The results demonstrate the generation of robust pure spin current in both structures without charge current. The mechanism is attributed to the spatial inversion antisymmetric spin density and the spatial inversion symmetry of the geometrical structures. Additionally, we find that an even number of connectors is required for structures with carbon tetragons as connectors, while any number of connectors can form pure spin currents for structures with carbon hexagon connectors. Moreover, larger pure spin currents can be obtained when using hexagons as connectors. These findings have significant implications for the design of spintronic devices with composite nanostructures.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Physics, Condensed Matter
Surender Pratap, Vipin Kumar
Summary: The study reveals that the edge states in ZGNR strongly depend on factors such as N, M*a, and the strength of the potential well, affecting the transmission coefficient significantly. Furthermore, the behavior of LDOS and transmission also strongly relies on the number of configurations in the system.
PHYSICA B-CONDENSED MATTER
(2021)
Article
Physics, Multidisciplinary
Tinggui Chen, Baizhan Xia, Dejie Yu, Chuanxing Bi
Summary: This study proposes a gradient phononic crystal structure for enhanced acoustic sensing. By breaking the symmetry of the PC structure, topologically protected edge states are introduced, resulting in topological acoustic rainbow trapping. The robustness and enhancement properties are verified numerically and experimentally.
