Spin-orbit interaction(SOI)can be introduced by the proximity effect to modulate the electronic properties of graphene-based heterostructures.In this work,we stack trilayer WSe_(2) on Bernal tetralayer graphene to inv...Spin-orbit interaction(SOI)can be introduced by the proximity effect to modulate the electronic properties of graphene-based heterostructures.In this work,we stack trilayer WSe_(2) on Bernal tetralayer graphene to investigate the influence of SOI on the anomalous Hall effect(AHE).In this structurally asymmetric device,by comparing the magnitude of AHE at positive and negative displacement fields,we find that AHE is strongly enhanced by bringing electrons in proximity to the WSe_(2) layer.Meanwhile,the enhanced AHE signal persists up to 80 K,providing important routes for topological device applications at high temperatures.展开更多
Recent experimental findings have demonstrated the occurrence of superconductivity in Bernal bilayer graphene when induced by a magnetic field.In this study,we conduct a theoretical investigation of the potential pair...Recent experimental findings have demonstrated the occurrence of superconductivity in Bernal bilayer graphene when induced by a magnetic field.In this study,we conduct a theoretical investigation of the potential pairing symmetry within this superconducting system.By developing a theoretical model,we primarily calculate the free energy of the system with p+ip-wave parallel spin pairing,p+ip-wave anti-parallel spin pairing and d+i d-wave pairing symmetry.Our results confirm that the magnetic field is indeed essential for generating the superconductivity.We discover that the p+ip-wave parallel spin pairing leads to a lower free energy for the system.The numerical calculations of the energy band structure,zero-energy spectral function and density of states for each of the three pairing symmetries under consideration show a strong consistency with the free energy results.展开更多
Tetralayer graphene has shown several interesting properties such as tunable Lifshitz transitions,helical edge states,and high-temperature anomalous Hall effects.The band structure,which directly relates to these phen...Tetralayer graphene has shown several interesting properties such as tunable Lifshitz transitions,helical edge states,and high-temperature anomalous Hall effects.The band structure,which directly relates to these phenomena,has so far been predominantly determined by fitting Landau-level spectra.Here,by characterizing the electronic capacitance,we reveal unprecedented details of its band structure:the energy shift between the heavy-and light-mass band edges in the conduction band is much larger than that in the valence band.Their responses to displacement fields are also distinct:while the former increases monotonically and significantly,the latter first decreases and then increases slightly.Our results suggest that the interlayer interactions and hopping parameters are more complex than previously expected,calling for precise measurements of band structures in various multilayer van der Waals systems.展开更多
基金Project supported by the National Key R&D Program of China(Grant Nos.2021YFA1400100 and 2024YFA1409700)the National Natural Science Foudation of China(Grant Nos.12374168 and T2325026)。
文摘Spin-orbit interaction(SOI)can be introduced by the proximity effect to modulate the electronic properties of graphene-based heterostructures.In this work,we stack trilayer WSe_(2) on Bernal tetralayer graphene to investigate the influence of SOI on the anomalous Hall effect(AHE).In this structurally asymmetric device,by comparing the magnitude of AHE at positive and negative displacement fields,we find that AHE is strongly enhanced by bringing electrons in proximity to the WSe_(2) layer.Meanwhile,the enhanced AHE signal persists up to 80 K,providing important routes for topological device applications at high temperatures.
基金Project supported by the National Natural Science Foundation of China (Grant No.12074130)the Natural Science Foundation of Guangdong Province (Grant No.2021A1515012340)。
文摘Recent experimental findings have demonstrated the occurrence of superconductivity in Bernal bilayer graphene when induced by a magnetic field.In this study,we conduct a theoretical investigation of the potential pairing symmetry within this superconducting system.By developing a theoretical model,we primarily calculate the free energy of the system with p+ip-wave parallel spin pairing,p+ip-wave anti-parallel spin pairing and d+i d-wave pairing symmetry.Our results confirm that the magnetic field is indeed essential for generating the superconductivity.We discover that the p+ip-wave parallel spin pairing leads to a lower free energy for the system.The numerical calculations of the energy band structure,zero-energy spectral function and density of states for each of the three pairing symmetries under consideration show a strong consistency with the free energy results.
基金supported by the National Natural Science Foundation of China(Grant Nos.123B1037 and 12274402)the National Key Research and Development Program of China(Grant No.2024YFA1409700).
文摘Tetralayer graphene has shown several interesting properties such as tunable Lifshitz transitions,helical edge states,and high-temperature anomalous Hall effects.The band structure,which directly relates to these phenomena,has so far been predominantly determined by fitting Landau-level spectra.Here,by characterizing the electronic capacitance,we reveal unprecedented details of its band structure:the energy shift between the heavy-and light-mass band edges in the conduction band is much larger than that in the valence band.Their responses to displacement fields are also distinct:while the former increases monotonically and significantly,the latter first decreases and then increases slightly.Our results suggest that the interlayer interactions and hopping parameters are more complex than previously expected,calling for precise measurements of band structures in various multilayer van der Waals systems.
