Manipulating magnetic domain structure plays a key role in advanced spintronics devices.Theoretical rationale is that the labyrinthine domain structure,normally appearing in ferromagnetic thin films with strong magnet...Manipulating magnetic domain structure plays a key role in advanced spintronics devices.Theoretical rationale is that the labyrinthine domain structure,normally appearing in ferromagnetic thin films with strong magnetic anisotropy,shows a great potential to increase data storage density for designing magnetic nonvolatile memory and logic devices.However,an electrical control of labyrinthine domain structure remains elusive.Here,we demonstrate the gate-driven evolution of labyrinthine domain structures in an itinerant ferromagnet Cr_(7)Te_(8).By combining electric transport measurements and micromagnetic finite difference simulations,we find that the hysteresis loop of anomalous Hall effect in Cr_(7)Te_(8)samples shows distinct features corresponding to the generation of labyrinthine domain structures.The labyrinthine domain structures are found to be electrically tunable via Li-electrolyte gating,and such gate-driven evolution in Cr_(7)Te_(8)originates from the reduction of the magnetic anisotropic energy with gating,revealed by our micromagnetic simulations.Our results on the gate control of anomalous Hall effect in an itinerant magnetic material provide an opportunity to understand the formation and evolution of labyrinthine domain structures,paving a new route towards electric-field driven spintronics.展开更多
We have successfully grown an arsenopyrite marcasite type RhSb2 single crystal, and systematically investigated its crystal structure, electrical transport, magnetic susceptibility, heat capacity, and thermodynamic pr...We have successfully grown an arsenopyrite marcasite type RhSb2 single crystal, and systematically investigated its crystal structure, electrical transport, magnetic susceptibility, heat capacity, and thermodynamic properties. We found that the temperature-dependent resistivity exhibits a bad metal behavior with a board peak around 200 K. The magnetic susceptibility of RhSb2 shows diamagnetism from 300 K to 2 K. The low-temperature specific heat shows a metallic behavior with a quite small electronic specific-heat coefficient. No phase transition is observed in both specific heat and magnetic susceptibility data. The Hall resistivity measurements show that the conduction carriers are dominated by electrons with ne = 8.62 × 10^(18) cm^(-3) at 2 K, and the electron carrier density increases rapidly above 200 K without change sign. Combining with ab-initio band structure calculations, we showed that the unusual peak around 200 K in resistivity is related to the distinct electronic structure of RhSb_2. In addition, a large thermopower S(T) about -140 μV/K is observed around 200 K, which might be useful for future thermoelectric applications.展开更多
The exploration of topological Dirac semimetals with intrinsic superconductivity can be a most plausible way to discover topological superconductors.We propose that type-II Dirac semimetal states exist in the band str...The exploration of topological Dirac semimetals with intrinsic superconductivity can be a most plausible way to discover topological superconductors.We propose that type-II Dirac semimetal states exist in the band structure of TaC,a well-known s-wave superconductor,by using the first-principles calculations and theκ· p effective model.The tilted gapless Dirac cones,which are composed of Ta d and C p orbitals and are protected by C4v symmetry,are found to be below the Fermi level.The bands from Ta d orbitals are greatly coupled with the acoustic modes around the zone boundary,indicating their significant contribution to the superconductivity.The relatively high transition temperature^10.5 K is estimated to be consistent with the experimental data.To bring the type-II Dirac points close to chemical potential,hole doping is needed.This seems to decrease the transition temperature a lot,making the realization of topological superconductivity impossible.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.92365203,52072168,51861145201,52302180,and 12204232)the National Key Research and Development Program of China(Grant No.2021YFA1202901)+1 种基金the Science and Technology Development Project of Henan Province(Grant No.242102230140)the China Postdoctoral Science Foundation(Grant No.2024M750775)。
文摘Manipulating magnetic domain structure plays a key role in advanced spintronics devices.Theoretical rationale is that the labyrinthine domain structure,normally appearing in ferromagnetic thin films with strong magnetic anisotropy,shows a great potential to increase data storage density for designing magnetic nonvolatile memory and logic devices.However,an electrical control of labyrinthine domain structure remains elusive.Here,we demonstrate the gate-driven evolution of labyrinthine domain structures in an itinerant ferromagnet Cr_(7)Te_(8).By combining electric transport measurements and micromagnetic finite difference simulations,we find that the hysteresis loop of anomalous Hall effect in Cr_(7)Te_(8)samples shows distinct features corresponding to the generation of labyrinthine domain structures.The labyrinthine domain structures are found to be electrically tunable via Li-electrolyte gating,and such gate-driven evolution in Cr_(7)Te_(8)originates from the reduction of the magnetic anisotropic energy with gating,revealed by our micromagnetic simulations.Our results on the gate control of anomalous Hall effect in an itinerant magnetic material provide an opportunity to understand the formation and evolution of labyrinthine domain structures,paving a new route towards electric-field driven spintronics.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11674375,11634015,11925408,and 11674369)the National Basic Research Program of China(Grant Nos.2016YFA0300600,2016YFA030240,2017YFA0302901,and 2018YFA0305700)+4 种基金the Strategic Priority Research Program and Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(Grant Nos.QYZDB-SSW-SLH013,XDB28000000,and XXH13506-202)the Science Challenge Project of China(Grant No.TZ2016004)the K.C.Wong Education Foundation,China(Grant No.GJTD-2018-01)the Beijing Natural Science Foundation,China(Grant No.Z180008)the Beijing Municipal Science and Technology Commission,China(Grant No.Z181100004218001)。
文摘We have successfully grown an arsenopyrite marcasite type RhSb2 single crystal, and systematically investigated its crystal structure, electrical transport, magnetic susceptibility, heat capacity, and thermodynamic properties. We found that the temperature-dependent resistivity exhibits a bad metal behavior with a board peak around 200 K. The magnetic susceptibility of RhSb2 shows diamagnetism from 300 K to 2 K. The low-temperature specific heat shows a metallic behavior with a quite small electronic specific-heat coefficient. No phase transition is observed in both specific heat and magnetic susceptibility data. The Hall resistivity measurements show that the conduction carriers are dominated by electrons with ne = 8.62 × 10^(18) cm^(-3) at 2 K, and the electron carrier density increases rapidly above 200 K without change sign. Combining with ab-initio band structure calculations, we showed that the unusual peak around 200 K in resistivity is related to the distinct electronic structure of RhSb_2. In addition, a large thermopower S(T) about -140 μV/K is observed around 200 K, which might be useful for future thermoelectric applications.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11974076,11674369 and 11925408)the Natural Science Foundation of Fujian Province of China(Grant No.2018J06001)+4 种基金the Beijing Natural Science Foundation(Grant No.Z180008)Beijing Municipal Science and Technology Commission(Grant No.Z191100007219013)National Key Research and Development Program of China(Grant Nos.2016YFA0300600 and 2018YFA0305700)the K.C.Wong Education Foundation(Grant No.GJTD-2018-01)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB33000000).
文摘The exploration of topological Dirac semimetals with intrinsic superconductivity can be a most plausible way to discover topological superconductors.We propose that type-II Dirac semimetal states exist in the band structure of TaC,a well-known s-wave superconductor,by using the first-principles calculations and theκ· p effective model.The tilted gapless Dirac cones,which are composed of Ta d and C p orbitals and are protected by C4v symmetry,are found to be below the Fermi level.The bands from Ta d orbitals are greatly coupled with the acoustic modes around the zone boundary,indicating their significant contribution to the superconductivity.The relatively high transition temperature^10.5 K is estimated to be consistent with the experimental data.To bring the type-II Dirac points close to chemical potential,hole doping is needed.This seems to decrease the transition temperature a lot,making the realization of topological superconductivity impossible.
