Article
Nanoscience & Nanotechnology
Faizan Ahmad, Rachana Kumar, Sunil Singh Kushvaha, Mahesh Kumar, Pramod Kumar
Summary: This study analyzed the n-GaN/p-Bi2Se3 topological heterojunction using Raman spectroscopy and ultrafast transient absorption spectroscopy, exploring the surface states, energy levels, charge transfer, and carrier relaxation processes. Electrical measurements were also conducted to investigate the influence of interface states on the electrical and optical performance.
NPJ 2D MATERIALS AND APPLICATIONS
(2022)
Review
Chemistry, Physical
Kushal Mazumder, Parasharam M. Shirage
Summary: Topological Insulators are a new class of materials with gapless surface states and potential applications. Bi2Se3, with high bulk band gap and unique surface states, shows outstanding performance in transport properties, thin films, and nanoparticle applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Analytical
Yujiu Jiang, Peng Zhu, Jinge Zhao, Shanshan Li, Yetong Wu, Xiaolu Xiong, Xu Zhang, Yuxiang Liu, Jiangyue Bai, Zihang Wang, Shiqi Xu, Minxuan Wang, Tinglu Song, Zhiwei Wang, Weizhi Wang, Junfeng Han
Summary: In this work, a facile and label-free electrochemical biosensor based on intrinsic topological insulator (TI) Bi2Se3 and peptide was designed for the detection of immune checkpoint molecules. The biosensor showed stable and sensitive electron transport due to the robust surface states of Bi2Se3 with low electronic noise. The peptide served as a suitable recognition unit for immune checkpoint molecules, as it could be easily synthesized and chemically modified, and had good biocompatibility and bioavailability. The designed peptide/Bi2Se3 biosensor demonstrated a linear detection range from 3.6 x 10-10 mg mL-1 to 3.6 x 10-5 mg mL-1 and a detection limit of 1.07 x 10-11 mg mL-1. It also exhibited good selectivity and stability.
ANALYTICA CHIMICA ACTA
(2023)
Article
Chemistry, Multidisciplinary
Sukanta Nandi, Shany Cohen, Danveer Singh, Michal Poplinger, Pilkhaz Nanikashvili, Doron Naveh, Tomer Lewi
Summary: This study investigates the mid-infrared (MIR) properties of chemical vapor deposition-grown Bi2Se3 nanobeams using a combination of far-field and near-field nanoscale imaging and spectroscopy. The results reveal the high refractive index values of Bi2Se3 and demonstrate its Mie resonances in the MIR. The study also provides experimental evidence for the potential applications of Bi2Se3 in quantum circuitry, nonlinear generation, high-Q metaphotonics, and photodetection.
Article
Physics, Applied
Shailja Sharma, Shiv Kumar, Amit Kumar, Kenya Shimada, C. S. Yadav
Summary: This study presents the structural, magnetotransport, and angle-resolved photoemission spectroscopy (ARPES) of Ag-doped Bi2Se3 single crystals. The results show that Ag-doping leads to metallic behavior in the resistivity, magnetoresistance satisfying Kohler's rule, and the dominance of electrons as charge carriers. The ARPES spectra confirm the shift of the Dirac point of the topological surface states towards higher binding energy for Ag-doped samples.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Applied
Yanan Liu, Zhongyao Li
Summary: The coupling of topological interface states in Bi2Se3/Bi2Se3 and TlSe/TlSe junctions leads to an energy gap at the Dirac point, which exponentially decays with increasing interface spacing. The law of exponential decay can help identify the formation of interface states and suggests that the coupling is caused by quantum tunneling. Intercalating hexagonal BN can greatly enhance the interfacial coupling, while bilayer BN or single atomic Au layer intercalation can further enhance this coupling effect.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Blaz Belec, Nina Kostevsek, Giulia Della Pelle, Sebastjan Nemec, Slavko Kralj, Martina Bergant Marusic, Sandra Gardonio, Mattia Fanetti, Matjaz Valant
Summary: This study investigated the possibility of using silica as a biocompatible coating for Bi2Se3 nanoparticles, instead of ethylene-glycol. The results showed that, except for nanoparticles with a thick silica layer of approximately 200 nm, the coated nanoparticles retained their optical properties. Compared to ethylene-glycol coated nanoparticles, these silica coated nanoparticles exhibited improved photo-thermal conversion and required lower concentrations to reach the desired temperatures. In vitro experiments demonstrated that silica coated nanoparticles were biocompatible, unlike ethylene-glycol coated nanoparticles.
Article
Chemistry, Physical
Dan Wang, Cui-E Hu, Li-Gang Liu, Min Zhang, Xiang-Rong Chen
Summary: In this study, an effective method to introduce magnetism into topological insulators was obtained, and single crystal C-Bi2Se3 was successfully fabricated. The structural, electrical and magnetic properties of doped non-magnetic element X (B, C, and N) in Bi, Se1, Se2, and VDW gap sites of Bi2Se3 were investigated. It was found that C doping in Bi2Se3 resulted in the formation of impurity bands inside the bulk inverted energy gap near the Fermi level. Theoretical calculations and experiments confirmed that carbon-doped Bi2Se3 is ferromagnetic, which provides a plan for manipulating topological properties and exploring spintronic applications.
Article
Quantum Science & Technology
Jonghoon Kim, Kwangsik Jeong, Hanbum Park, Seokbo Hong, Dajung Kim, Gihwan Nam, Seungwon Rho, Hee Jun Shin, Chul Kang, Mann-Ho Cho
Summary: In this work, the suppression of surface properties in Bi2Se3 of various thicknesses grown on antiferromagnetic NiO, which has a strong exchange interaction is investigated. The study found that under perpendicular magnetic fields, a drastic decrease in mobility mu and in the number of phase coherent channels alpha in 5 QL Bi2Se3 on NiO are observed. Additionally, the THz transmission study shows that an increase in the surface penetration depth xi can accelerate the hybridization of surface states, which is also verified using the optical pump THz probe. This rapid collapse of surface states indicates the unique role of antiferromagnetic materials in band overlap, suggesting that the topological surface nature can be modulated by forming an antiferromagnet-topological insulator heterostructure.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Materials Science, Multidisciplinary
Na Li, Yun-bin Sun, Rui Sun, Xu Yang, Wei Zhang, Zong-kai Xie, Jia-nan Liu, Yan Li, Yang Li, Zi-zhao Gong, Xiang-qun Zhang, Wei He, Zhao-hua Cheng
Summary: Topological insulators with distinct topological surface states have been widely investigated for spintronics and quantum information devices. This study reveals that the topological surface states can significantly accelerate ultrafast demagnetization and enhance the damping factor of heterostructures. These findings have implications for future topological spintronic devices or quantum information processing.
Article
Physics, Multidisciplinary
Tae Gwan Park, Jae Ho Jeon, Seung-Hyun Chun, Sunghun Lee, Fabian Rotermund
Summary: This study investigates the interface effects between VSe2 and topological insulator Bi2Se3 using ultrafast time-resolved spectroscopy. The results show that VSe2 as an electrode does not alter the surface state of Bi2Se3 and enables efficient electron transfer and current flow.
COMMUNICATIONS PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Yogesh Kumar, Prince Sharma, V. P. S. Awana
Summary: In this study, bismuth selenide thin films of varying thicknesses were deposited on a SiO2 substrate. The films were characterized and their transport properties were investigated, revealing the thickness dependence of weak anti-localization effect in Bi2Se3/SiO2 thin films.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Chemistry, Multidisciplinary
Tiancong Zhu, Alexander J. Bishop, Tong Zhou, Menglin Zhu, Dante J. O'Hara, Alexander A. Baker, Shuyu Cheng, Robert C. Walko, Jacob J. Repicky, Tao Liu, Jay A. Gupta, Chris M. Jozwiak, Eli Rotenberg, Jinwoo Hwang, Igor Zutic, Roland K. Kawakami
Summary: This study successfully synthesized vdW MnBi2Se4 crystals using nonequilibrium molecular beam epitaxy, revealing its easy-plane anisotropy and gapless surface state, making it a new material that remains a topological insulator above the magnetic-ordering temperature.
Article
Nanoscience & Nanotechnology
Wen Wang, Haocheng Lei, Ashu Wang
Summary: In this study, the friction behavior of Bi2Se3 was investigated using conductive friction force microscopy under ultra-high vacuum conditions. The experimental results revealed a non-monotonic enhancement of friction, with the emergence of two friction peaks. Further investigations demonstrated that this anomalous friction behavior originated from the formation and rupture of multiple thermally activated sub-contacts.
Article
Chemistry, Physical
Mao Ye, Kenta Kuroda, Mikhail M. Otrokov, Anastasia G. Ryabishchenkova, Qi Jiang, Arthur Ernst, Evgueni Chulkov, Masashi Nakatake, Masashi Arita, Taichi Okuda, Tomohiro Matsushita, Laszlo Toth, Hiroshi Daimon, Kenya Shimada, Yoshifumi Ueda, Akio Kimura
Summary: The study reveals that deposited Ag atoms on the topological insulator Bi2Se3 surface are stabilized beneath the surface instead of being adsorbed on the topmost surface. The presence of Ag atoms does not disturb the topological surface states. Through angle-resolved photoemission spectroscopy and first-principles calculations, the distribution and most favorable locations of Ag atoms beneath the surface are identified.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Physics, Applied
Xin Liao, Chang Xu, Zi-Pu Fan, Ying-Ying Lan, Na Li, Chun-Guang Chu, An-Qi Wang, Dong Sun, Zhi-Min Liao
Summary: The combination of 2D Dirac semimetal graphene and 3D counterpart Cd3As2 in Dirac heterostructures can overcome the weak optical absorption in graphene-based devices and the dark current in pure Cd3As2 photodetectors, leading to high-performance photodetectors with broadband detection, high sensitivity, and rapid response.
APPLIED PHYSICS LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Jiapeng Xu, Zhimin Liao, Qi Wang, Bo Liu, Xiaoli Tang, Zhiyong Zhong, Lei Zhang, Yuanjing Zhang, Huaiwu Zhang, Lichuan Jin
Summary: This study experimentally demonstrates that the transmission efficiency of low-k spin waves can be enhanced through surface metallization of yttrium iron garnet (YIG), resulting in increased group velocity and low spin-pumping efficiency. The competition between spin-pumping effects and the introduction of enhanced group velocity by metal decoration describes the essence of partial signal enhancement in the spin-wave transmission spectrum. The work provides a practical way to achieve spin-wave manipulation and low-loss transmission.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Yue Zhao, Gang Wu, Kuan-Ming Hung, Jiung Cho, Miri Choi, Cormac O. Coileain, Georg S. Duesberg, Xiang-Kui Ren, Ching-Ray Chang, Han-Chun Wu
Summary: In this work, we fabricated field effect transistor gas sensors based on mechanically exfoliated van der Waals (vdW) layered materials and investigated their electrical field-dependent gas sensing properties. The results showed good agreement between experimental and theoretical values, indicating the validity of the Langmuir absorption model for vdW materials. Additionally, we demonstrated that the device sensing behavior strongly depends on carrier availability, leading to giant sensitivities and strong selectivity at the sensitivity singularity. Furthermore, our study revealed that these features can be utilized to quickly detect and differentiate low concentrations of mixed hazardous gases using sensor arrays.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Xiaodong Wen, Yuqian Sang, Yongyu Zhang, Feng Ge, Guangyin Jing, Yan He
Summary: Microorganisms need to develop strategies to adjust to environmental variations for survival. This study reveals how a population of cooperating Serratia marcescens bacteria respond to a deteriorating habitat. When exposed to increasing doses of antibiotics, the bacteria transform turbulent flows to jet flows, by which they transfer material and/or information. The detailed spatiotemporal transport behavior in this microscale active turbulence is elucidated using single-nanoparticle tracking. The bacterial collective response to stronger antibiotics stimulates a state of superdiffusion in the active flows.
Article
Physics, Multidisciplinary
Hao-Nan Cui, Guang-Yu Zhu, Jian-Kun Wang, Jia-Jie Yang, Wen-Zhuang Zheng, Ben-Chuan Lin, Zhi-Min Liao, Shuo Wang, Da-Peng Yu
Summary: A novel negative magnetoresistance effect has been observed in Cd3As2 nanowires, which is related to the massless Dirac or Weyl fermions in these nanostructures. The negative magnetoresistance can reach -16% at 1.5 K and persists to -1% at room temperature. The gate tuning and angle dependence suggest that this effect is different from the chiral anomaly and may be attributed to percolating current paths induced by charge puddles and disorder.
Article
Chemistry, Multidisciplinary
Huan Zheng, Ningzhe Yan, Wei Feng, Yanan Liu, Hao Luo, Guangyin Jing
Summary: Gravity has a significant impact on the spatial distribution and behavior of bacteria in both still and flowing fluids. Bacteria such as Escherichia coli show a clear separation in dense mediums and tend to cluster near the upper wall. The buoyancy force plays a crucial role in trapping the bacteria on the wall, and this effect is significantly suppressed when flow is introduced. The chiral-induced transverse drift capability is diminished by buoyancy force but can be recovered in a still medium by excluding the intrinsic swimming motility. These findings provide insights into bacterial behavior and offer a controllable way to manipulate their distribution.
Article
Chemistry, Multidisciplinary
Bingchen Che, Dan Sun, Chen Zhang, Jiaqing Hou, Wei Zhao, Guangyin Jing, Yuguang Mu, Yaoyu Cao, Liang Dai, Ce Zhang
Summary: Mechanically induced chromosome reorganization is important in transcriptional regulation, but the interplay between chromosome reorganization and transcription activities is complicated. By introducing DNA, packaging proteins, and transcription factor NF-KB into a fluidic chip with varying spatial confinement, it was found that strong nanoconfinement suppresses higher-order folding of protein-DNA complexes and leads to increased NF-KB binding. Overall, these results reveal a pathway of how intranuclear geometrical cues alter the open/closed state of a DNA-protein complex and affect transcription activities.
Article
Chemistry, Physical
Congcong Zhang, Teng Tu, Jingyue Wang, Yongchao Zhu, Congwei Tan, Liang Chen, Mei Wu, Ruixue Zhu, Yizhou Liu, Huixia Fu, Jia Yu, Yichi Zhang, Xuzhong Cong, Xuehan Zhou, Jiaji Zhao, Tianran Li, Zhimin Liao, Xiaosong Wu, Keji Lai, Binghai Yan, Peng Gao, Qianqian Huang, Hai Xu, Huiping Hu, Hongtao Liu, Jianbo Yin, Hailin Peng
Summary: The scaling of silicon-based transistors faces challenges such as interface imperfections and gate current leakage at sub-ten-nanometre technology nodes. To achieve smaller channel sizes, less interfacial scattering, and more efficient gate-field penetration, high-mobility two-dimensional layered semiconductors are expected as channel materials. However, progress in 2D electronics is hindered by the lack of a high dielectric constant dielectric with an atomically flat and dangling-bond-free surface.
Article
Physics, Multidisciplinary
Hao-Nan Cui, Ze-Nan Wu, Jian-Kun Wang, Guang-Yu Zhu, Jia-Jie Yang, Wen-Zhuang Zheng, Zhi-Min Liao, Shuo Wang, Ben-Chuan Lin, Dapeng Yu
Summary: This study reports a novel nonlinear behavior of chiral anomaly in the Dirac semimetal Cd3As2, characterized by resistance-increasing and current source-strengthening properties at an intermediate magnetic field of approximately 5 T. Trivial factors such as thermal effects, geometric artifacts, and anisotropy were ruled out through angle-dependence experiments. Additionally, non-Ohmic electric quantum oscillations were observed when a high direct current of 300 μA was applied, suggesting the formation of quantized levels due to Bloch oscillation in the high DC regime.
Article
Biochemical Research Methods
Chen Zhang, Jiaqing Hou, Yang Zeng, Liang Dai, Wei Zhao, Guangyin Jing, Dan Sun, Yaoyu Cao, Ce Zhang
Summary: By fabricating a gradient nanochannel array on a slightly tilted nano-stage, we systematically investigate the dynamics of DNA translocation through nanoconfinement and its dependence on biomolecule size and geometrical features. Our results demonstrate that DNA undergoes conformational transition during translocation through nanochannels, driven either by electric field or flow, and the deformation energy required for translocation depends on both chemical environmental conditions and nanochannel dimensions. These findings suggest that optically fabricated gradient nanochannel arrays are suitable platforms for optimizing experimental conditions for biomedical applications.
Article
Physics, Multidisciplinary
Chun-Guang Chu, An-Qi Wang, Zhi-Min Liao
Summary: Topological semimetals are exotic phases of quantum matter with gapless electronic excitation protected by symmetry. The hybrid system of topology and superconductivity has attracted wide interest due to its potential application in topological quantum computing. Recent experimental progress of topological semimetal-superconductor heterojunctions is reviewed, including the Josephson current as a mode filter and the detection and manipulation of topological superconductivity and Majorana zero modes. Outlooks of future research on topological semimetal-superconductor heterojunctions and their application in Majorana braiding and topological quantum computing are discussed.
ACTA PHYSICA SINICA
(2023)
Article
Materials Science, Multidisciplinary
An-Qi Wang, Peng-Zhan Xiang, Zhi-Min Liao
Summary: We observe nonreciprocal spin transport in two-dimensional topological insulator Cd3As2 nanoplates under nonlocal configuration, where the nonlocal spin voltage amplitude exhibits anomalous nonreciprocity with respect to the direction of local bias current. This unusual nonreciprocity can be well understood by combining the charge current spreading and thermally induced spin polarization of topological surface states.
Article
Materials Science, Multidisciplinary
Jing-Zhi Fang, Hao-Nan Cui, Shuo Wang, Jing-Di Lu, Guang-Yu Zhu, Xin-Jie Liu, Mao-Sen Qin, Jian-Kun Wang, Ze-Nan Wu, Yan-Fei Wu, Shou-Guo Wang, Zhen-Sheng Zhang, Zhongming Wei, Jinxing Zhang, Ben-Chuan Lin, Zhi-Min Liao, Dapeng Yu
Summary: We report on the electrically tunable exchange bias in the van der Waals MnBi2Te4/Cr2Ge2Te6 heterostructure, where the exchange bias emerges over a critical magnetic field and reaches its maximum near the band gap. Moreover, the exchange bias mainly affects the net ferromagnetic (FM) layers of MnBi2Te4 rather than the pure FM insulator Cr2Ge2Te6. This van der Waals heterostructure provides a promising platform for studying the novel exchange bias effect and exploring the potential applications in spintronics or high-Tc quantum anomalous Hall effect.
Article
Materials Science, Multidisciplinary
Zhen-Cun Pan, Chun-Guang Chu, Jing-Jing Chen, An-Qi Wang, Zhen-Bing Tan, Wen-Zheng Xu, Jun Xu, Xiu-Mei Ma, Da-Peng Yu, Zhi-Min Liao
Summary: Transport evidence for 1D helical edge states in MoTe2 thin flakes is reported, and Altshuler-Aronov-Spivak interference and temperature evolution of the fast Fourier transform amplitude are observed, deepening the understanding of higher-order topological properties of MoTe2.
Article
Multidisciplinary Sciences
Chun-Guang Chu, Jing-Jing Chen, An-Qi Wang, Zhen-Bing Tan, Cai-Zhen Li, Chuan Li, Alexander Brinkman, Peng-Zhan Xiang, Na Li, Zhen-Cun Pan, Hai-Zhou Lu, Dapeng Yu, Zhi-Min Liao
Summary: In this study, broad edge supercurrent is observed in Dirac semimetal Cd3As2-based Josephson junctions, indicating the presence of non-Hermitian skin effect. The wide and large edge supercurrent, as well as the observed supercurrent nonlocality, suggest the interplay between band topology and non-Hermiticity in exploiting exotic topological matter.
NATURE COMMUNICATIONS
(2023)
