Aiming to enhance the bandwidth in near-memory computing,this paper proposes a SSA-over-array(SSoA)architecture.By relocating the secondary sense amplifier(SSA)from dynamic random access memory(DRAM)to the logic die a...Aiming to enhance the bandwidth in near-memory computing,this paper proposes a SSA-over-array(SSoA)architecture.By relocating the secondary sense amplifier(SSA)from dynamic random access memory(DRAM)to the logic die and repositioning the DRAM-to-logic stacking interface closer to the DRAM core,the SSoA overcomes the layout and area limitations of SSA and master DQ(MDQ),leading to improvements in DRAM data-width density and frequency,significantly enhancing bandwidth density.The quantitative evaluation results show a 70.18 times improvement in bandwidth per unit area over the baseline,with a maximum bandwidth of 168.296 Tbps/Gb.We believe the SSoA is poised to redefine near-memory computing development strategies.展开更多
Dear Editor, Histone methylation is a dynamic process that plays important roles in gene transcription regulation, and a number of enzymes have been shown to catalyze the removal of methyl marks [1]. Shi et al. （200...Dear Editor, Histone methylation is a dynamic process that plays important roles in gene transcription regulation, and a number of enzymes have been shown to catalyze the removal of methyl marks [1]. Shi et al. （2004） identified one of the amino oxidases, lysine-specific demethylase 1 （LSD1）, as the first specific demethylase for both mono（me） and dimethylation （me2） of H3K4 and H3K9 in humans [2].展开更多
We present the design of a diffractive grating structure and get the optimal parameters which can achieve more than 75%coupling efficiency（CE） between single-mode fiber and silicon-on-insulator（SOI） waveguide thro...We present the design of a diffractive grating structure and get the optimal parameters which can achieve more than 75%coupling efficiency（CE） between single-mode fiber and silicon-on-insulator（SOI） waveguide through 2D finite-different time-domain（FDTD） simulation.The proposed architecture has a uniform structure with no bottom reflection element or silicon overlay.The structure,including grating couplers,adiabatic tapers and interconnection waveguides can be fabricated on the SOI waveguide with only a single electron-beam lithography（ICP） step,which is CMOS-compatible.A relatively high coupling efficiency of 47.2%was obtained at a wavelength of 1562 nm.展开更多
Graphene field-effect transistors have been intensively studied.However,in order to fabricate devices with more complicated structures,such as the integration with waveguide and other two-dimensional materials,we need...Graphene field-effect transistors have been intensively studied.However,in order to fabricate devices with more complicated structures,such as the integration with waveguide and other two-dimensional materials,we need to transfer the exfoliated graphene samples to a target position.Due to the small area of exfoliated graphene and its random distribution,the transfer method requires rather high precision.In this paper,we systematically study a method to selectively transfer mechanically exfoliated graphene samples to a target position with a precision of sub-micrometer.To characterize the doping level of this method,we transfer graphene flakes to pre-patterned metal electrodes,forming graphene field-effect transistors.The hole doping of graphene is calculated to be 2.16×10^12cm^-2.In addition,we fabricate a waveguide-integrated multilayer graphene photodetector to demonstrate the viability and accuracy of this method.A photocurrent as high as 0.4 μA is obtained,corresponding to a photoresponsivity of 0.48 mA/W.The device performs uniformly in nine illumination cycles.展开更多
基金supported in part by the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No.XDB44000000。
文摘Aiming to enhance the bandwidth in near-memory computing,this paper proposes a SSA-over-array(SSoA)architecture.By relocating the secondary sense amplifier(SSA)from dynamic random access memory(DRAM)to the logic die and repositioning the DRAM-to-logic stacking interface closer to the DRAM core,the SSoA overcomes the layout and area limitations of SSA and master DQ(MDQ),leading to improvements in DRAM data-width density and frequency,significantly enhancing bandwidth density.The quantitative evaluation results show a 70.18 times improvement in bandwidth per unit area over the baseline,with a maximum bandwidth of 168.296 Tbps/Gb.We believe the SSoA is poised to redefine near-memory computing development strategies.
文摘Dear Editor, Histone methylation is a dynamic process that plays important roles in gene transcription regulation, and a number of enzymes have been shown to catalyze the removal of methyl marks [1]. Shi et al. （2004） identified one of the amino oxidases, lysine-specific demethylase 1 （LSD1）, as the first specific demethylase for both mono（me） and dimethylation （me2） of H3K4 and H3K9 in humans [2].
基金Project supported by the National Key Research and Development Program of China(No.2016YFB0402404)the High-Tech Research and Development Program of China(Nos.2013AA031401,2015AA016902,2015AA016904)the National Natural Foundation of China(Nos.61674136,61435002,61176053,61274069)
文摘We present the design of a diffractive grating structure and get the optimal parameters which can achieve more than 75%coupling efficiency（CE） between single-mode fiber and silicon-on-insulator（SOI） waveguide through 2D finite-different time-domain（FDTD） simulation.The proposed architecture has a uniform structure with no bottom reflection element or silicon overlay.The structure,including grating couplers,adiabatic tapers and interconnection waveguides can be fabricated on the SOI waveguide with only a single electron-beam lithography（ICP） step,which is CMOS-compatible.A relatively high coupling efficiency of 47.2%was obtained at a wavelength of 1562 nm.
基金Project supported by the National Key Research and Development Program of China(No.2016YFB0402404)the High-Tech Research and Development Program of China(Nos.2013AA031401,2015AA016902,2015AA016904)the National Natural Foundation of China(Nos.61674136,61176053,61274069,61435002)
文摘Graphene field-effect transistors have been intensively studied.However,in order to fabricate devices with more complicated structures,such as the integration with waveguide and other two-dimensional materials,we need to transfer the exfoliated graphene samples to a target position.Due to the small area of exfoliated graphene and its random distribution,the transfer method requires rather high precision.In this paper,we systematically study a method to selectively transfer mechanically exfoliated graphene samples to a target position with a precision of sub-micrometer.To characterize the doping level of this method,we transfer graphene flakes to pre-patterned metal electrodes,forming graphene field-effect transistors.The hole doping of graphene is calculated to be 2.16×10^12cm^-2.In addition,we fabricate a waveguide-integrated multilayer graphene photodetector to demonstrate the viability and accuracy of this method.A photocurrent as high as 0.4 μA is obtained,corresponding to a photoresponsivity of 0.48 mA/W.The device performs uniformly in nine illumination cycles.
