Showing papers by "Jian-Hao Chen published in 2023"
TL;DR: In this article , Bernal-stacked bilayer graphene (BLG) atop few-layered CrOCl, exhibiting an over 1 GΩ-resistance insulating state in a widely accessible gate voltage range.
Abstract: The realization of graphene gapped states with large on/off ratios over wide doping ranges remains challenging. Here, we investigate heterostructures based on Bernal-stacked bilayer graphene (BLG) atop few-layered CrOCl, exhibiting an over-1-GΩ-resistance insulating state in a widely accessible gate voltage range. The insulating state could be switched into a metallic state with an on/off ratio up to 107 by applying an in-plane electric field, heating, or gating. We tentatively associate the observed behavior to the formation of a surface state in CrOCl under vertical electric fields, promoting electron-electron (e-e) interactions in BLG via long-range Coulomb coupling. Consequently, at the charge neutrality point, a crossover from single particle insulating behavior to an unconventional correlated insulator is enabled, below an onset temperature. We demonstrate the application of the insulating state for the realization of a logic inverter operating at low temperatures. Our findings pave the way for future engineering of quantum electronic states based on interfacial charge coupling.
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TL;DR: In this article , the authors report the continuous argon ions irradiation of itinerant Fe3GeTe2, a two-dimensional ferromagnetic metal, with the modification to its transport properties measured in situ.
Abstract: We report the continuous argon ions irradiation of itinerant Fe3GeTe2, a two-dimensional ferromagnetic metal, with the modification to its transport properties measured in situ. Our results show that defects generated by argon ions irradiation can significantly weaken the magnetization (M) and coercive field (Hc) of Fe3GeTe2, demonstrating the tunable magnetism of this material. Specifically, at base temperature, we observed a reduction of M and Hc by up to 40% and 62.4%, respectively. After separating the contribution from different mechanisms based on the Tian-Ye-Jin (TYJ) scaling relation, it’s the skew scattering that dominates the contribution to anomalous Hall effect in argon ions irradiated Fe3GeTe2. These findings highlight the potential of in situ transport modification as an effective method for tailoring the magnetic properties of two-dimensional magnetic materials, and provides new insights into the mechanisms underlying the tunable magnetism in Fe3GeTe2.
TL;DR: In this article , a high sensitivity quantum capacitance measurement with an improved radio frequency superheterodyne bridge technique for probing the electronic characteristic of Ge/SiGe 2D hole gas (2DHG) at low temperatures and under a perpendicular magnetic field B⊥ was reported.
Abstract: Quantum capacitance of two-dimensional (2D) systems contains useful physical information. Here, we report a high sensitivity quantum capacitance measurement with an improved radio frequency superheterodyne bridge technique for probing the electronic characteristic of Ge/SiGe 2D hole gas (2DHG) at low temperatures and under a perpendicular magnetic field B⊥. At low fields, a rapid decrease in quantum capacitance following [Formula: see text] dependence is observed, indicating an abrupt change in chemical potential near the gate boundary at high frequencies; at high fields, a series of capacitance oscillations are observed due to the Landau quantization and Zeeman splitting of the Ge/SiGe 2DHG, where gate-dependent effective [Formula: see text] factor under B⊥ is extracted. These results represent implementation of the high-precision capacitance measurement for exploring the physical properties of Ge/SiGe 2DHG.