查看更多>>摘要：Controlling the size and distribution of potential barriers within a medium of interacting particles can unveil unique collective behaviors and innovative functionalities.We introduce a unique superconducting hybrid device using a novel artificial spin ice structure composed of asymmetric nanomagnets.This structure forms a distinc-tive superconducting pinning potential that steers unconventional motion of superconducting vortices,thereby inducing a magnetic nonreciprocal effect,in contrast to the electric nonreciprocal effect commonly observed in superconducting diodes.Furthermore,the polarity of the magnetic nonreciprocity is in situ reversible through the tunable magnetic patterns of artificial spin ice.Our findings demonstrate that artificial spin ice not only precisely modulates superconducting characteristics but also opens the door to novel functionalities,offering a groundbreaking paradigm for superconducting electronics.
查看更多>>摘要：Novel magnetic materials with non-trivial magnetic structures have led to exotic magnetic transport properties and significantly promoted the development of spintronics in recent years.Among them is the CrxTey family,the magnetism of which can persist above room temperature,thus providing an ideal system for potential spintronic applications.Here we report the synthesis of a new compound,Cr0.82Te,which demonstrates a record-high topological Hall effect at room temperature in this family.Cr0.82Te displays soft ferromagnetism below the Curie temperature of 340 K.The magnetic measurement shows an obvious magneto-crystalline anisotropy with the easy axis located in the ab plane.The anomalous Hall effect can be well explained by a dominating skew scattering mechanism.Intriguing,after removing the normal Hall effect and anomalous Hall effect,a topological Hall effect can be observed up to 300 K and reaches up to 1.14 μΩ·cm at 10 K,which is superior to most topological magnetic structural materials.This giant topological Hall effect possibly originates from the noncoplanar spin configuration during the spin flop process.Our work extends a new CrxTey system with topological non-trivial magnetic structure and broad prospects for spintronics applications in the future.
查看更多>>摘要：Graphene(Gr)with widely acclaimed characteristics,such as exceptionally long spin diffusion length at room temperature,provides an outstanding platform for spintronics.However,its inherent weak spin-orbit coupling(SOC)has limited its efficiency for generating the spin currents in order to control the magnetization switching process for applications in spintronics memories.Following the theoretical prediction on the enhancement of SOC in Gr by heavy atoms adsorption,here we experimentally observe a sizeable spin-orbit torques(SOTs)in Gr by the decoration of its surface with Pt adatoms in Gr/Pt(tpt)/FeNi trilayers with the optimal damping-like SOT efficiency around 0.55 by 0.6-nm-thick Pt layer adsorption.The value is nearly four times larger than that of the Pt/FeNi sample without Gr and nearly twice the value of the Gr/FeNi sample without Pt adsorption.The efficiency of the enhanced SOT in Gr by Pt adatoms is also demonstrated by the field-free SOT magnetization switching process with a relatively low critical current density around 5.4MA/cm2 in Gr/Pt/FeNi trilayers with the in-plane magnetic anisotropy.These findings pave the way for Gr spintronics applications,offering solutions for future low power consumption memories.
查看更多>>摘要：The discovery of ferromagnetic two-dimensional(2D)van der Waals(vdWs)materials provides an opportu-nity to explore intriguing physics and to develop innovative spin electronic devices.However,the main challenge for practical applications of vdWs ferromagnetic crystals lies in the weak intrinsic ferromagnetism and small per-pendicular magnetic anisotropy(PMA)above room temperature.Here,we report the intrinsic vdWs ferromag-netic crystal Fe3GaTe2,synthesized by the self-flux method,exhibiting a Curie temperature(TC)of 370K,a high saturation magnetization of 33.47 emu/g,and a large PMA energy density of approximately 4.17 × 105 J/m3.Fur-thermore,the magneto-optical effect is systematically investigated in Fe3GaTe2.The doubly degenerate E2g(Γ)mode reverses the helicity of incident photons,indicating the existence of pseudoangular-momentum(PAM)and chirality.Meanwhile,the non-degenerate non-chiral A1g(Γ)phonon exhibits a significant magneto-Raman effect under an external out-of-plane magnetic field.These results lay the groundwork for studying phonon chirality and magneto-optical phenomena in 2D magnetic materials,providing the feasibility for further fundamental research and applications in spintronic devices.
查看更多>>摘要：In the era of Internet of Things(IoTs),an energy-efficient ultraviolet(UV)photodetector(PD)is highly desirable considering the massive usage scenarios such as environmental sterilization,fire alarm and corona discharge monitoring.So far,common self-powered UV PDs are mainly based on metal-semiconductor hetero-structures or p-n heterojunctions,where the limited intrinsic built-in electric field restricts further enhancement of the photoresponsivity.In this work,an extremely low-voltage field-effect UV PD is proposed using a gate-drain shorted amorphous IGZO(a-IGZO)thin film transistor(TFT)architecture.A combined investigation of the experimental measurements and technology computer-aided design(TCAD)simulations suggests that the reverse current(IR)of field-effect diode(FED)is highly related with the threshold voltage(Vth)of the parental TFT,implying an enhancement-mode TFT is preferable to fabricate the field-effect UV PD with low dark current.Driven by a low bias of-0.1V,decent UV response has been realized including large UV/visible(R300/R550)rejection ratio(1.9 × 103),low dark current(1.15 × 10-12 A)as well as high photo-to-dark current ratio(PDCR,～103)and responsivity(1.89 A/W).This field-effect photodiode provides a new platform to construct UV PDs with well-balanced photoresponse performance at a low bias,which is attractive for designs of large-scale smart sensor networks with high energy efficiency.
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