Spin–momentum locking is a key feature of the topological surface state, which plays an important role in spintronics.The electrical detection of current-induced spin polarization protected by the spin–momentum lock...Spin–momentum locking is a key feature of the topological surface state, which plays an important role in spintronics.The electrical detection of current-induced spin polarization protected by the spin–momentum locking in nonmagnetic systems provides a new platform for developing spintronics, while previous studies were mostly based on magnetic materials.In this study, the spin transport measurement of Dirac semimetal Cd_(3)As_(2) was studied by three-terminal geometry, and a hysteresis loop signal with high resistance and low resistance state was observed. The hysteresis was reversed by reversing the current direction, which illustrates the spin–momentum locking feature of Cd_(3)As_(2). Furthermore, we realized the on–off states of the spin signals through electric modulation of the Fermi arc via the three-terminal configuration, which enables the great potential of Cd_(3)As_(2) in spin field-effect transistors.展开更多
We report a universal transfer methodology for producing artificial heterostructures of large-area freestanding single-crystalline WTe_(2) membranes on diverse target substrates.The transferred WTe_(2) membranes exhib...We report a universal transfer methodology for producing artificial heterostructures of large-area freestanding single-crystalline WTe_(2) membranes on diverse target substrates.The transferred WTe_(2) membranes exhibit a nondestructive structure with a carrier mobility comparable to that of as-grown films(∼179–1055 cm^(2)·V^(−1)·s^(−1)).Furthermore,the transferred membranes show distinct Shubnikov–de Haas quantum oscillations as well as weak localization/weak anti-localization.These results provide a new approach to the development of atom manufacturing and devices based on atomic-level,large-area topological quantum films.展开更多
Topological Weyl semimetal WTe2 with large-scale Him form has a promising prospect for new-generation spintronic devices.However,it remains a hard task to suppress the defect states in large-scale WTe2 films due to th...Topological Weyl semimetal WTe2 with large-scale Him form has a promising prospect for new-generation spintronic devices.However,it remains a hard task to suppress the defect states in large-scale WTe2 films due to the chemical nature.Here we significantly improve the crystalline quality and remove the Te vacancies in WTe2 films by post annealing.We observe the distinct Shubnikov-de Haas quantum oscillations in WTe2 films.The nontrivial Berry phase can be revealed by Landau fan diagram analysis.The Hall mobility of WTe2 films can reach 1245cm^2V^-1s^-1 and 1423cm^2V^-1s^-1 for holes and electrons with the carrier density of 5× 10^19 cm^-3 and 2 × 10^19 cm^-3,respectively.Our work provides a feasible route to obtain high-quality Weyl semimetal films for the future topological quantum device applications.展开更多
The ternary topological insulators Bi2Se3-xTex have attracted a great deal of attention due to their exotic physical and chemical properties.While most of the studies focus on the properties of these ternary TIs,limit...The ternary topological insulators Bi2Se3-xTex have attracted a great deal of attention due to their exotic physical and chemical properties.While most of the studies focus on the properties of these ternary TIs,limited research was performed to investigate the dynamic atomic stack of its crystal structure.We prepared highquality Bi2Se3-xTex thin films on Ga As(111)B substrates using molecular beam epitaxy,characterized with Raman spectroscopy,x-ray diffraction and photoelectron spectroscopy.It is found that when Se is replaced by Te,the preferred substituting sites are the middle layer at 0<x<1,and this is also valid for Se substituting Te at 2<x<3.In the middle region,the substituting atoms prefer to go to the first and the fifth layer.展开更多
基金Project supported by the National Key Research and Development Program of China (Grant Nos.2020YFA0309300 and 2022YFA1403700)the National Natural Science Foundation of China (Grant Nos.12004158,12074162,and 91964201)+2 种基金the Key-Area Research and Development Program of Guangdong Province (Grant No.2018B030327001)Guangdong Provincial Key Laboratory (Grant No.2019B121203002)Guangdong Basic and Applied Basic Research Foundation (Grant No.2022B1515130005)。
文摘Spin–momentum locking is a key feature of the topological surface state, which plays an important role in spintronics.The electrical detection of current-induced spin polarization protected by the spin–momentum locking in nonmagnetic systems provides a new platform for developing spintronics, while previous studies were mostly based on magnetic materials.In this study, the spin transport measurement of Dirac semimetal Cd_(3)As_(2) was studied by three-terminal geometry, and a hysteresis loop signal with high resistance and low resistance state was observed. The hysteresis was reversed by reversing the current direction, which illustrates the spin–momentum locking feature of Cd_(3)As_(2). Furthermore, we realized the on–off states of the spin signals through electric modulation of the Fermi arc via the three-terminal configuration, which enables the great potential of Cd_(3)As_(2) in spin field-effect transistors.
基金Supported by the National Key R&D Program of China(Grant No.2017YFA0206304)the National Natural Science Foundation of China(Grant Nos.11874203,61822403,U1732159,11774160,and 61427812)the Fundamental Research Funds for the Central Universities(Grant No.021014380080)。
文摘We report a universal transfer methodology for producing artificial heterostructures of large-area freestanding single-crystalline WTe_(2) membranes on diverse target substrates.The transferred WTe_(2) membranes exhibit a nondestructive structure with a carrier mobility comparable to that of as-grown films(∼179–1055 cm^(2)·V^(−1)·s^(−1)).Furthermore,the transferred membranes show distinct Shubnikov–de Haas quantum oscillations as well as weak localization/weak anti-localization.These results provide a new approach to the development of atom manufacturing and devices based on atomic-level,large-area topological quantum films.
基金the National Key R&D Program of China(Grant Nos.2017YFA0206304 and 2016YFA0300803)the National Natural Science Foundation of China(Grant Nos 61822403,11874203,11774160,61427812 and U1732159)+2 种基金the Fundamental Research Funds for the Central Universities(Grant Nos 021014380080 and 021014380113)the Natural Science Foundation of Jiangsu Province of China(Grant No BK20192006)Collaborative Innovation Center of Solid-State Lighting and Energy-Saving Elec tronics.
文摘Topological Weyl semimetal WTe2 with large-scale Him form has a promising prospect for new-generation spintronic devices.However,it remains a hard task to suppress the defect states in large-scale WTe2 films due to the chemical nature.Here we significantly improve the crystalline quality and remove the Te vacancies in WTe2 films by post annealing.We observe the distinct Shubnikov-de Haas quantum oscillations in WTe2 films.The nontrivial Berry phase can be revealed by Landau fan diagram analysis.The Hall mobility of WTe2 films can reach 1245cm^2V^-1s^-1 and 1423cm^2V^-1s^-1 for holes and electrons with the carrier density of 5× 10^19 cm^-3 and 2 × 10^19 cm^-3,respectively.Our work provides a feasible route to obtain high-quality Weyl semimetal films for the future topological quantum device applications.
基金Supported by the National Key Research and Development Program of China(Grant No.2016YFA0300803)the National Natural Science Foundation of China(Grant Nos.61474061,61674079,and 61974061)the Jiangsu Shuang Chuang Program and the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20140054)。
文摘The ternary topological insulators Bi2Se3-xTex have attracted a great deal of attention due to their exotic physical and chemical properties.While most of the studies focus on the properties of these ternary TIs,limited research was performed to investigate the dynamic atomic stack of its crystal structure.We prepared highquality Bi2Se3-xTex thin films on Ga As(111)B substrates using molecular beam epitaxy,characterized with Raman spectroscopy,x-ray diffraction and photoelectron spectroscopy.It is found that when Se is replaced by Te,the preferred substituting sites are the middle layer at 0<x<1,and this is also valid for Se substituting Te at 2<x<3.In the middle region,the substituting atoms prefer to go to the first and the fifth layer.
