Phase-change material(PCM)is generating widespread interest as a new candidate for artificial synapses in bioinspired computer systems.However,the amorphization process of PCM devices tends to be abrupt,unlike contin...Phase-change material(PCM)is generating widespread interest as a new candidate for artificial synapses in bioinspired computer systems.However,the amorphization process of PCM devices tends to be abrupt,unlike continuous synaptic depression.The relatively large power consumption and poor analog behavior of PCM devices greatly limit their applications.Here,we fabricate a GeTe/Sb2Te3 superlattice-like PCM device which allows a progressive RESET process.Our devices feature low-power consumption operation and potential high-density integration,which can effectively simulate biological synaptic characteristics.The programming energy can be further reduced by properly selecting the resistance range and operating method.The fabricated devices are implemented in both artificial neural networks(ANN)and convolutional neural network(CNN)simulations,demonstrating high accuracy in brain-like pattern recognition.展开更多
Emerging memristive devices offer enormous advantages for applications such as non-volatile memories and inmemory computing(IMC),but there is a rising interest in using memristive technologies for security application...Emerging memristive devices offer enormous advantages for applications such as non-volatile memories and inmemory computing(IMC),but there is a rising interest in using memristive technologies for security applications in the era of internet of things(IoT).In this review article,for achieving secure hardware systems in IoT,lowpower design techniques based on emerging memristive technology for hardware security primitives/systems are presented.By reviewing the state-of-the-art in three highlighted memristive application areas,i.e.memristive non-volatile memory,memristive reconfigurable logic computing and memristive artificial intelligent computing,their application-level impacts on the novel implementations of secret key generation,crypto functions and machine learning attacks are explored,respectively.For the low-power security applications in IoT,it is essential to understand how to best realize cryptographic circuitry using memristive circuitries,and to assess the implications of memristive crypto implementations on security and to develop novel computing paradigms that will enhance their security.This review article aims to help researchers to explore security solutions,to analyze new possible threats and to develop corresponding protections for the secure hardware systems based on low-cost memristive circuit designs.展开更多
In this letter,the Ta/HfO/BN/TiN resistive switching devices are fabricated and they exhibit low power consumption and high uniformity each.The reset current is reduced for the HfO/BN bilayer device compared with that...In this letter,the Ta/HfO/BN/TiN resistive switching devices are fabricated and they exhibit low power consumption and high uniformity each.The reset current is reduced for the HfO/BN bilayer device compared with that for the Ta/HfO/TiN structure.Furthermore,the reset current decreases with increasing BN thickness.The HfOlayer is a dominating switching layer,while the low-permittivity and high-resistivity BN layer acts as a barrier of electrons injection into TiN electrode.The current conduction mechanism of low resistance state in the HfO/BN bilayer device is space-chargelimited current(SCLC),while it is Ohmic conduction in the HfOdevice.展开更多
For the reliability and power consumption issues of Ethernet data transmission based on the field programmable gate array （FPGA）, a low-power consumption design method is proposed, which is suitable for FPGA impleme...For the reliability and power consumption issues of Ethernet data transmission based on the field programmable gate array （FPGA）, a low-power consumption design method is proposed, which is suitable for FPGA implementation. To reduce the dynamic power consumption of integrated circuit （IC） design, the proposed method adopts the dynamic control of the clock frequency. For most of the time, when the port is in the idle state or lower-rate state, users can reduce or even turn off the reading clock frequency and reduce the clock flip frequency in order to reduce the dynamic power consumption. When the receiving rate is high, the reading clock frequency will be improved timely to ensure that no data will lost. Simulated and verified by Modelsim, the proposed method can dynamically control the clock frequency, including the dynamic switching of high-speed and low-speed clock flip rates, or stop of the clock flip.展开更多
Perpendicular magnetic anisotropy-based magnetic tunnel junctions(p-MTJs) with low Gilbert damping constant(α) are of particular interest for fast and low-power consumption magnetic random-access memory(MRAM). Howeve...Perpendicular magnetic anisotropy-based magnetic tunnel junctions(p-MTJs) with low Gilbert damping constant(α) are of particular interest for fast and low-power consumption magnetic random-access memory(MRAM). However, obtaining a faster switching speed and lower power consumption is still a big challenge. Herein, we report a Mo-based perpendicular double free layer structure with a low Gilbert damping constant of 0.02 relative to W-based films, as measured by time-resolved magnetooptical Kerr effect equipment. To show the influence of different film structures on the Gilbert damping constant, we measured the Mo-based single free layer. Thereafter, we deposited the full stacks with the Mo-based double free layer and obtained a high tunneling magnetoresistance of 136.3% and high thermal stability. The results of high-resolution transmission electron microscopy(HR-TEM) and energy-dispersive X-ray spectroscopy(EDS) showed that the Mo-based films had better crystallinity,sharper interfaces, and weaker diffusion than the W-based films and thus produced a weaker external contribution of the Gilbert damping constant. As a result of the weak spin-orbit coupling in the Mo-based structure, the intrinsic contribution of the Gilbert damping constant was also weak, thereby leading to the small Gilbert damping constant of the Mo-based stacks. In addition, the macro-spin simulation results demonstrated that the magnetization switching by the spin transfer torque of the Mo-based MTJs was faster than that of the W-based MTJs. These findings help to understand the mechanism behind the good performance of Mo-based p-MTJ films and show the great promise of these structures in low-power consumption MRAM or other spintronic devices.展开更多
基金Project supported by the National Science and Technology Major Project of China(Grant No.2017ZX02301007-002)the National Key R&D Plan of China(Grant No.2017YFB0701701)the National Natural Science Foundation of China(Grant Nos.61774068 and 51772113).The authors acknowledge the support from Hubei Key Laboratory of Advanced Memories&Hubei Engineering Research Center on Microelectronics.
文摘Phase-change material(PCM)is generating widespread interest as a new candidate for artificial synapses in bioinspired computer systems.However,the amorphization process of PCM devices tends to be abrupt,unlike continuous synaptic depression.The relatively large power consumption and poor analog behavior of PCM devices greatly limit their applications.Here,we fabricate a GeTe/Sb2Te3 superlattice-like PCM device which allows a progressive RESET process.Our devices feature low-power consumption operation and potential high-density integration,which can effectively simulate biological synaptic characteristics.The programming energy can be further reduced by properly selecting the resistance range and operating method.The fabricated devices are implemented in both artificial neural networks(ANN)and convolutional neural network(CNN)simulations,demonstrating high accuracy in brain-like pattern recognition.
基金supported by the DFG(German Research Foundation)Priority Program Nano Security,Project MemCrypto(Projektnummer 439827659/funding id DU 1896/2–1,PO 1220/15–1)the funding by the Fraunhofer Internal Programs under Grant No.Attract 600768。
文摘Emerging memristive devices offer enormous advantages for applications such as non-volatile memories and inmemory computing(IMC),but there is a rising interest in using memristive technologies for security applications in the era of internet of things(IoT).In this review article,for achieving secure hardware systems in IoT,lowpower design techniques based on emerging memristive technology for hardware security primitives/systems are presented.By reviewing the state-of-the-art in three highlighted memristive application areas,i.e.memristive non-volatile memory,memristive reconfigurable logic computing and memristive artificial intelligent computing,their application-level impacts on the novel implementations of secret key generation,crypto functions and machine learning attacks are explored,respectively.For the low-power security applications in IoT,it is essential to understand how to best realize cryptographic circuitry using memristive circuitries,and to assess the implications of memristive crypto implementations on security and to develop novel computing paradigms that will enhance their security.This review article aims to help researchers to explore security solutions,to analyze new possible threats and to develop corresponding protections for the secure hardware systems based on low-cost memristive circuit designs.
基金supported by the National Natural Science Foundation of China(Grant Nos.61274113,11204212,61404091,51502203,and 51502204)the Tianjin Natural Science Foundation,China(Grant Nos.14JCZDJC31500 and 14JCQNJC00800)the Tianjin Science and Technology Developmental Funds of Universities and Colleges,China(Grant No.20130701)
文摘In this letter,the Ta/HfO/BN/TiN resistive switching devices are fabricated and they exhibit low power consumption and high uniformity each.The reset current is reduced for the HfO/BN bilayer device compared with that for the Ta/HfO/TiN structure.Furthermore,the reset current decreases with increasing BN thickness.The HfOlayer is a dominating switching layer,while the low-permittivity and high-resistivity BN layer acts as a barrier of electrons injection into TiN electrode.The current conduction mechanism of low resistance state in the HfO/BN bilayer device is space-chargelimited current(SCLC),while it is Ohmic conduction in the HfOdevice.
基金supported by the Natural Science Foundation of China under Grant No.61376024 and No.61306024Natural Science Foundation of Guangdong Province under Grant No.S2013040014366Basic Research Programme of Shenzhen under Grant No.JCYJ20140417113430642 and No.JCYJ20140901003939020
文摘For the reliability and power consumption issues of Ethernet data transmission based on the field programmable gate array （FPGA）, a low-power consumption design method is proposed, which is suitable for FPGA implementation. To reduce the dynamic power consumption of integrated circuit （IC） design, the proposed method adopts the dynamic control of the clock frequency. For most of the time, when the port is in the idle state or lower-rate state, users can reduce or even turn off the reading clock frequency and reduce the clock flip frequency in order to reduce the dynamic power consumption. When the receiving rate is high, the reading clock frequency will be improved timely to ensure that no data will lost. Simulated and verified by Modelsim, the proposed method can dynamically control the clock frequency, including the dynamic switching of high-speed and low-speed clock flip rates, or stop of the clock flip.
基金supported by the National Key R&D Program of China(Grant No.2018YFB0407602)the National Natural Science Foundation of China(Grant Nos.92164206,12104031,11904016,and 61627813)+4 种基金the Science and Technology Major Project of Anhui Province(Grant No.202003a05020050)the International Collaboration Project(Grant No.B16001)the National Key Technology Program of China(Grant No.2017ZX01032101)the Beihang Hefei Innovation Research Institute Project(Grant Nos.BHKX-19-01,and BHKX-19-02)the Guangdong Provincial Department of Science and Technology(Grant No.2020A1515011425)。
文摘Perpendicular magnetic anisotropy-based magnetic tunnel junctions(p-MTJs) with low Gilbert damping constant(α) are of particular interest for fast and low-power consumption magnetic random-access memory(MRAM). However, obtaining a faster switching speed and lower power consumption is still a big challenge. Herein, we report a Mo-based perpendicular double free layer structure with a low Gilbert damping constant of 0.02 relative to W-based films, as measured by time-resolved magnetooptical Kerr effect equipment. To show the influence of different film structures on the Gilbert damping constant, we measured the Mo-based single free layer. Thereafter, we deposited the full stacks with the Mo-based double free layer and obtained a high tunneling magnetoresistance of 136.3% and high thermal stability. The results of high-resolution transmission electron microscopy(HR-TEM) and energy-dispersive X-ray spectroscopy(EDS) showed that the Mo-based films had better crystallinity,sharper interfaces, and weaker diffusion than the W-based films and thus produced a weaker external contribution of the Gilbert damping constant. As a result of the weak spin-orbit coupling in the Mo-based structure, the intrinsic contribution of the Gilbert damping constant was also weak, thereby leading to the small Gilbert damping constant of the Mo-based stacks. In addition, the macro-spin simulation results demonstrated that the magnetization switching by the spin transfer torque of the Mo-based MTJs was faster than that of the W-based MTJs. These findings help to understand the mechanism behind the good performance of Mo-based p-MTJ films and show the great promise of these structures in low-power consumption MRAM or other spintronic devices.
