This paper discusses heat-assisted magnetic recording (HAMR) media requirements and challenges for areal densities (AD) beyond 1 Tb/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Based on recent roadmap discussions the focus is primarily granular chemically ordered L10 FePtX-Y-perpendicular with reduced average grain size down to 〈D〉 = 3-5 nm relative current CoCrPt based perpendicular (PMR) 7-9 nm. In HAMR combination of thermal...

Because of its high storage density with superior scalability, low integration cost and reasonably access speed, spin-torque transfer random memory (STT RAM) appears to have a promising potential replace SRAM as last-level on-chip cache (e.g., L2 or L3 cache) for microprocessors. Due unique operational characteristics device magnetic tunneling junction (MTJ), STT RAM is inherently subject write latency versus read tradeoff that determined by the cell size. This paper first quantitatively...

In this paper, a novel and facile synthetic method of 3-mercaptopropionic acid functionalized copper nanoclusters with aggregation-induced emission (AIE) induced by Cu2+ (Cu2+@MPA-Cu NCs) was developed one-pot reaction as fluorescent probe for the detection sulfide ion (S2–). The prepared Cu2+@MPA-Cu NCs behaved aggregated clusters had strong pink fluorescence under 365 nm UV light excellent at 610 nm. quantum yield increased from 0.56% to 4.8% before after added. presence S2– would strongly...

We propose a magnetic and electric level spin-transfer torque random access memory (STT-RAM) cell model to simulate the write operation of an STT-RAM. The tunneling junction (MTJ) is modified take into account electrical response MOS transistor that connected MTJ. A dynamic design flow also proposed minimize any unnecessary margin in STT-RAM by leveraging from new model. with one-transistor-one-MTJ (1T1J) structure shows our technique can reduce more than 22% area, compared conventional at...

Thermal fluctuation effects on mean and variation of spin torque induced magnetic element switching are analyzed. Asymptotic forms the time distribution from stochastic Landau–Lifshitz–Gilbert equation, numerical solutions first second moments corresponding Fokker–Planck used to characterize current density for whole range, thermal reversal region nanosecond dynamic region. It is shown that as scales become shorter, distributions narrower, whereas may broader. This paper provides a physical...

As one promising candidate for next-generation nonvolatile memory technologies, spin-transfer torque random access (STT-RAM) has demonstrated many attractive features, such as nanosecond time, high integration density, non-volatility, and good CMOS process compatibility. In this paper, we reveal an important fact that been neglected in STT-RAM designs long: the write operation of a cell is asymmetric based on switching direction MTJ (magnetic tunneling junction) device: mean deviation...

The rapidly increased demands for memory in electronic industry and the significant technical scaling challenges of all conventional technologies motivated researches on next generation technology. As one promising candidate, spin-transfer torque random access (STT-RAM) features fast time, high density, non-volatility, good CMOS process compatibility. However, like other nano-scale devices, performance reliability STT-RAM cells are severely affected by variations, intrinsic device operating...

The rapidly increased demands for memory in electronic industry and the significant technical scaling challenges of all conventional technologies motivated researches on next generation technology. As one promising candidate, spin-transfer torque random access (STT-RAM) features fast time, high density, non-volatility, good CMOS process compatibility. However, like other nano-scale devices, performance reliability STT-RAM cells are severely affected by variations, intrinsic device operating...

In this work, we study the access (read and write) scheme of newly proposed Multi-Level Cell Spin-Transfer Torque Random Access Memory (MLC STT-RAM) from both circuit design architectural perspectives. Based on physical principles resistance state transition MLC STT-RAM, a read circuitry based Dichotomic search algorithm three write schemes with various complexities - simple, complex, hybrid schemes. The level evaluations were conducted to analyze power performance tradeoffs in each...

Among all the emerging memories, Spin-Transfer Torque Random Access Memory (STT-RAM) has demonstrated many promising features such as fast access speed, nonvolatility, excellent scalability, and compatibility to CMOS process. However, large process variations of both magnetic tunneling junction (MTJ) MOS transistors in scaled technologies severely limit yield STT-RAM chips. In this work, we proposed a new sensing scheme, named nondestructive self-reference sensing, or NSRS, for STT-RAM. By...

We proposed a novel self-reference sensing scheme for Spin-Transfer Torque Random Access Memory (STT-RAM) to overcome the large bit-to-bit variation of Magnetic Tunneling Junction (MTJ) resistance. Different from all existing schemes, our solution is nondestructive: The stored value in STT-RAM cell does NOT need be overwritten by reference value. And hence, long write-back operation (of original value) eliminated. robustness analyses and nondestructive are also presented. measurement results...

Spin-transfer torque random access memory (STT-RAM) becomes a promising technology for future computing systems its fast time, high density, nonvolatility, and small write current. However, like all the other nanotechnologies, STT-RAM suffers from process variations environment fluctuations, which significantly affect performance stability of magnetic tunneling junction (MTJ) devices. In this study, we combine circuit simulations to quantitatively analyze impacts MTJ CMOS on designs. Both...

We have investigated high-quality MgO tunnel junctions with a range of barrier thickness in order to identify the underlying physical mechanism responsible for dielectric breakdown. Two types breakdown (“soft” and “hard”) were observed. Soft was observed few percent devices. This mode is not intrinsic attributed junction imperfections. The hard occurs because critical electric field reached across barrier. Other possible mechanisms, such as thermally driven mass diffusion or charge trapping,...

As one promising candidate for next-generation nonvolatile memory technologies, spin-transfer torque random access (STT-RAM) has demonstrated many attractive features, such as nanosecond time, high integration density, non-volatility, and good CMOS process compatibility. In this paper, we reveal an important fact that been neglected in STT-RAM designs long: the write operation of a cell is asymmetric based on switching direction MTJ (magnetic tunneling junction) device: mean deviation...

We proposed a novel self-reference sensing scheme for Spin-Transfer Torque Random Access Memory (STT-RAM) to overcome the large bit-to-bit variation of Magnetic Tunneling Junction (MTJ) resistance. Different from all existing schemes, our solution is nondestructive: The stored value in STT-RAM cell does NOT need be overwritten by reference value. And hence, long write-back operation (of original value) eliminated. robustness analyses and nondestructive are also presented. measurement results...

The transiting exoplanetary system WASP-11/HAT-P-10 was observed using the CCD camera at Yunnan Observatories, China from 2008 to 2011, and four new transit light curves were obtained. Combined with published radial velocity measurements, are analyzed along available photometric data literature Markov Chain Monte Carlo technique, refined physical parameters of derived, which compatible results two discovery groups, respectively. planet mass is Mp = 0.526 ± 0.019 MJ, same as West et al.'s...

Abstract The timescales incorporated into the Primary Frequency Standard (PFS) exhibit excellent stability and accuracy. However, during dead time of PFS, reliability timescale can be compromised. To address this issue, a resilient timekeeping algorithm with Multi-observation Fusion Kalman Filter (MFKF) is proposed. This fuses frequency measurements from hydrogen masers various reference standards, including PFS commercial cesium beam atomic clocks. simulation results show that deviation...

We proposed a combined magnetic and circuit level technique to explore the design methodology of Spin-Torque Transfer RAM (SPRAM). A dynamic model tunneling junction (MTJ), which is based upon measured spin torque induced magnetization switching behavior, also proposed. The response CMOS circuitry characterized by SPICE used as input our MTJ simulate behavior SPRAM cell. By using this technique, we explored margin cell with one-transistor-one-MTJ (1T1J) structure. Simulation results show...

Spin-transfer torque random access memory (STT-RAM) has demonstrated great potentials as a universal for its fast speed, zero standby power, excellent scalability, and simplicity of cell structure. However, large process variations both magnetic tunneling junction (MTJ) CMOS severely limit the yield STT-RAM chips prevent massive production from happening. In this paper, we analyze compare impacts on various sensing schemes design. On top it, propose novel voltage-driven nondestructive...

Integration of high density spin transfer torque magnetoresistance random access memory requires a thin stack (less than 15 nm) perpendicular magnetic tunnel junction (p-MTJ). We propose an innovative approach to solve this challenging problem by reducing the thickness and/or moment reference layer. A layer structure CoFeB/Ta/Co/Pd/Co has 60% conventional thick including [Co/Pd] multilayers. demonstrate that magnetization can be realized anti-ferromagnetically coupling pinned with strong...