We investigated the electric controllable spin-filtering effect in a zigzag phosphorene nanoribbon(ZPNR) based normal–antiferromagnet–normal junction. Two ferromagnets are closely coupled to the edges of the nanorib...We investigated the electric controllable spin-filtering effect in a zigzag phosphorene nanoribbon(ZPNR) based normal–antiferromagnet–normal junction. Two ferromagnets are closely coupled to the edges of the nanoribbon and form the edge-to-edge antiferromagnetism. Under an in-plane electric field, the two degenerate edge bands of the edge-to-edge antiferromagnet split into four spin-polarized sub-bands and a 100% spin-polarized current can be easily induced with the maximal conductance 2e~2/h. The spin polarization changes with the strength of the electric field and the exchange field,and changes sign at opposite electric fields. The spin-polarized current switches from one edge to the other by reversing the direction of the electric field. The edge current can also be controlled spatially by changing the electric potential of the scattering region. The manipulation of edge current is useful in spin-transfer-torque magnetic random-access memory and provides a practical way to develop controllable spintronic devices.展开更多
An attitude controller using the second order sliding mode control methodology with a backstepping approach(SOSMCB)is designed and implemented for a spinning missile with two internal moving mass blocks.The system c...An attitude controller using the second order sliding mode control methodology with a backstepping approach(SOSMCB)is designed and implemented for a spinning missile with two internal moving mass blocks.The system consists of a rigid body and two radial internal moving mass blocks and its mathematical model is established based on Newtonian mechanics.The control scheme integrates a second order sliding mode control algorithm into the last step of the backstepping approach,and its stability is proved by means of a Lyapunov function.The performance of the controller is demonstrated by numerical simulations,the results show that the attitude controller is stable and effective.展开更多
Spins in silicon(Si)quantum dots(QDs),as a new type of solid state qubits,is expected to be a competitive contender in the long run of scalable quantum computation[1].Quantum computation is believed to be the next-gen...Spins in silicon(Si)quantum dots(QDs),as a new type of solid state qubits,is expected to be a competitive contender in the long run of scalable quantum computation[1].Quantum computation is believed to be the next-generation computing technology to solve the problems that no classical computer can feasibly tackle.In the last decade.展开更多
The variation of mass, and moment of inertia of a spin-stabilized spacecraft leads to concern about the nutation instability. Here a careful analysis on the nutation instability is performed on a spacecraft propelled ...The variation of mass, and moment of inertia of a spin-stabilized spacecraft leads to concern about the nutation instability. Here a careful analysis on the nutation instability is performed on a spacecraft propelled by solid rocket booster(SRB). The influences of specific solid propellant designs on transversal angular velocity are discussed. The results show that the typical SRB of End Burn suppresses the non-principal axial angular velocity. On the contrary, the frequently used SRB of Radial Burn could amplify the transversal angular velocity. The nutation instability caused by a design of Radial Burn could be remedied by the addition of End Burn at the same time based on the study of the combination design of both End Burn and Radial Burn.The analysis of the results proposes the design conception of how to control the nutation motion.The method is suitable to resolve the nutation instability of solid rocket motor with complex propellant patterns.展开更多
Subject Code:A04With the support by the National Natural Science Foundation of China,the research team led by Prof.Dong Jianwen(董建文)at the State Key Laboratory of Optoelectronic Materials and Technologies&Schoo...Subject Code:A04With the support by the National Natural Science Foundation of China,the research team led by Prof.Dong Jianwen(董建文)at the State Key Laboratory of Optoelectronic Materials and Technologies&School of Physics,Sun Yat-sen University,discovered the control of spin and topology in valley photonic crystals,which was published in Nature Materials(2017,DOI:10.1038/NMAT4087).展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12174077 and 12174051)the Science Foundation of GuangDong Province (Grant No.2021A1515012363)GuangDong Basic and Applied Basic Research Foundation (Grant No.2022A1515110011)。
文摘We investigated the electric controllable spin-filtering effect in a zigzag phosphorene nanoribbon(ZPNR) based normal–antiferromagnet–normal junction. Two ferromagnets are closely coupled to the edges of the nanoribbon and form the edge-to-edge antiferromagnetism. Under an in-plane electric field, the two degenerate edge bands of the edge-to-edge antiferromagnet split into four spin-polarized sub-bands and a 100% spin-polarized current can be easily induced with the maximal conductance 2e~2/h. The spin polarization changes with the strength of the electric field and the exchange field,and changes sign at opposite electric fields. The spin-polarized current switches from one edge to the other by reversing the direction of the electric field. The edge current can also be controlled spatially by changing the electric potential of the scattering region. The manipulation of edge current is useful in spin-transfer-torque magnetic random-access memory and provides a practical way to develop controllable spintronic devices.
基金Supported by the National Natural Science Foundation of China(11202023)
文摘An attitude controller using the second order sliding mode control methodology with a backstepping approach(SOSMCB)is designed and implemented for a spinning missile with two internal moving mass blocks.The system consists of a rigid body and two radial internal moving mass blocks and its mathematical model is established based on Newtonian mechanics.The control scheme integrates a second order sliding mode control algorithm into the last step of the backstepping approach,and its stability is proved by means of a Lyapunov function.The performance of the controller is demonstrated by numerical simulations,the results show that the attitude controller is stable and effective.
文摘Spins in silicon(Si)quantum dots(QDs),as a new type of solid state qubits,is expected to be a competitive contender in the long run of scalable quantum computation[1].Quantum computation is believed to be the next-generation computing technology to solve the problems that no classical computer can feasibly tackle.In the last decade.
基金supported by the National Natural Science Foundation of China (Nos. 11502086 and 11502087)
文摘The variation of mass, and moment of inertia of a spin-stabilized spacecraft leads to concern about the nutation instability. Here a careful analysis on the nutation instability is performed on a spacecraft propelled by solid rocket booster(SRB). The influences of specific solid propellant designs on transversal angular velocity are discussed. The results show that the typical SRB of End Burn suppresses the non-principal axial angular velocity. On the contrary, the frequently used SRB of Radial Burn could amplify the transversal angular velocity. The nutation instability caused by a design of Radial Burn could be remedied by the addition of End Burn at the same time based on the study of the combination design of both End Burn and Radial Burn.The analysis of the results proposes the design conception of how to control the nutation motion.The method is suitable to resolve the nutation instability of solid rocket motor with complex propellant patterns.
文摘Subject Code:A04With the support by the National Natural Science Foundation of China,the research team led by Prof.Dong Jianwen(董建文)at the State Key Laboratory of Optoelectronic Materials and Technologies&School of Physics,Sun Yat-sen University,discovered the control of spin and topology in valley photonic crystals,which was published in Nature Materials(2017,DOI:10.1038/NMAT4087).