The magnetic field resolution of the tunnel magneto-resistive (TMR) sensors has been improving and it reaches below 1.0 pT/Hz0.5 at low frequency. The real-time measurement of the magnetocardiography (MCG) and the measurement of the magnetoencephalography (MEG) have been demonstrated by developed TMR sensors. Although the MCG and MEG have been applied to diagnosis of diseases, the conventional MCG/MEG system using superconducting quantum interference devices (SQUIDs) cannot measure the signal by touching the body, the body must be fixed, and maintenance costs are huge. The MCG/MEG system with TMR sensors operating at room temperature have the potential to solve these problems. In addition, it has the great advantage that it does not require a special magnetic shielded room. Further developments are expected to progress to maximize these unique features of TMR sensors.

Lead bromide-based perovskite organic-inorganic quantum-well films incorporated polycyclic aromatic chromophores into the organic layer (in other words, hybrid quantum-wells combined lead bromide semiconductor and organic semiconductors) were prepared by use of the spin-coating technique from the DMF solution in which PbBr2 and alkyl ammonium bromides which were linked polycyclic aromatics, pyrene, phenanthrene, and anthracene. When the pyrene-linked methyl ammonium bromide, which has a relatively small molecular cross-section with regard to the inorganic semiconductor plane, was employed, a lead bromide-based perovskite structure was successfully formed in the spin-coated films. When the phenanthrene-linked and anthracene-linked ammonium bromides, whose chromophore have large molecular cross-sections, were employed, lead bromide-based perovskite structures were not formed. However, the introduction of longer alkyl chains into the aromatics-linked ammonium bromides made it possible to form the perovskite structure.

Fast switching speed, low power consumption, and good stability are some of the important properties of spin transfer torque assisted voltage controlled magnetic anisotropy magnetic tunnel junction (STT-assisted VCMA-MTJ) which makes the non-volatile full adder (NV-FA) based on it attractive for Internet of Things. However, the effects of process variations on the performances of STT-assisted VCMA-MTJ and NV-FA will be more and more obvious with the downscaling of STT-assisted VCMA-MTJ and the improvement of chip integration. In this paper, a more accurate electrical model of STT-assisted VCMA-MTJ is established on the basis of the magnetization dynamics and the process variations in film growth process and etching process. In particular, the write voltage is reduced to 0.7 V as the film thickness is reduced to 0.9 nm. The effects of free layer thickness variation (γtf) and oxide layer thickness variation (γtox) on the state switching as well as the effect of tunnel magnetoresistance ratio variation (β) on the sensing margin (SM) are studied in detail. Considering that the above process variations follow Gaussian distribution, Monte Carlo simulation is used to study the effects of the process variations on the writing and output operations of NV-FA. The result shows that the state of STT-assisted VCMA-MTJ can be switched under -0.3%≤γtf≤6% or -23%≤γtox≤0.2%. SM is reduced by 16.0% with β increases from 0 to 30%. The error rates of writing ‘0’ in the NV-FA can be reduced by increasing Vb1 or increasing positive Vb2. The error rates of writing ‘1’ can be reduced by increasing Vb1 or decreasing negative Vb2. The reduction of the output error rates can be realized effectively by increasing the driving voltage (Vdd).

Predicting the grasping point accurately and quickly is crucial for successful robotic manipulation. However, to commercially deploy a robot, such as a dishwasher robot in a commercial kitchen, we also need to consider the constraints of limited usable resources. We present a deep learning method to predict the grasp position when using a single suction gripper for picking up objects. The proposed method is based on a shallow network to enable lower training costs and efficient inference on limited resources. Costs are further reduced by collecting data in a custom-built synthetic environment. For evaluating the proposed method, we developed a system that models a commercial kitchen for a dishwasher robot to manipulate symmetric objects. We tested our method against a model-fitting method and an algorithm-based method in our developed commercial kitchen environment and found that a shallow network trained with only the synthetic data achieves high accuracy. We also demonstrate the practicality of using a shallow network in sequence with an object detector for ease of training, prediction speed, low computation cost, and easier debugging.

We review a new superconducting element, called “magnetic Josephson junctions” with a magnetic barrier instead of the insulating barrier of conventional Josephson junctions. We classify the three types of magnetic barrier, i.e., diluted alloy, conventional ferromagnet, and magnetic multilayer barriers, and introduce various new physics such as the π-state arising in magnetic Josephson junctions due to the interaction between superconductivity and magnetism.

We propose a compact magnetic tunnel junction (MTJ) model for circuit simulation by de-facto standard SPICE in this paper. It is implemented by Verilog-A language which makes it easy to simulate MTJs with other standard devices. Based on the switching probability, we smoothly connect the adiabatic precessional model and the thermal activation model by using an interpolation technique based on the cubic spline method. We can predict the switching time after a current is applied. Meanwhile, we use appropriate physical models to describe other MTJ characteristics. Simulation results validate that the model is consistent with experimental data and effective for MTJ/CMOS hybrid circuit simulation.

In automotive control systems, the potential risks of software defects have been increasing due to growing software complexity driven by advances in electric-electronic control. Some kind of defects such as race conditions can rarely be detected by testing or simulations because these defects manifest themselves only in some rare executions. Model checking, which employs an exhaustive state-space exploration, is effective for detecting such defects. This paper reports our approach to applying model checking techniques to real-world automotive control programs. It is impossible to directly model check such programs because of their large size and high complexity; thus, it is necessary to derive, from the program under verification, a model that is amenable to model checking. Our approach uses the SPIN model checker as well as in-house tools that facilitate this process. One of the key features implemented in these tools is boundary-adjustable program slicing, which allows the user to specify and extract part of the source code that is relevant to the verification problem of interest. The conversion from extracted code into Promela, SPIN's input language, is performed using one of the tools in a semi-automatic manner. This approach has been used for several years in practice and found to be useful even when the code size of the software exceeds 400 KLOC.

We have investigated the influence of the ferromagnet magnetization on the transport properties of intrinsic Josephson junctions in Co/Au/BSCCO/Au/Co hybrid structure under applied magnetic fields. The current-voltage characteristic at 77K in a zero-field showed the multiple quasiparticle branches with hysteresis similar to that of conventional intrinsic Josephson junctions. On the other hand, it was observed that the critical current shows a clear asymmetric field dependence with respect to the direction of the field sweep, resulting in hysteretic behavior. By comparing the field dependence of critical current with magnetization curve of the sample, we found that the critical current is strongly suppressed in the antiparallel configuration of the relative magnetization orientation of two Co layers due to the accumulation of spin-polarized quasiparticles in intrinsic Josephson junctions. The observed suppression of the critical current is as large as more than 20%.

The physics and applications of superconducting phase shifts and their control in superconducting systems are reviewed herein. The operation principle of almost all superconducting devices is related to the superconducting phase, and an efficient control of the phase is crucial for improving the performance and scalability. Furthermore, employing new methods to shift or control the phase may lead to the development of novel superconducting device applications, such as cryogenic memory and quantum computing devices. Recently, as a result of the progress in nanofabrication techniques, superconducting phase shifts utilizing π states have been realized. In this review, following a discussion of the basic physics of phase propagation and shifts in hybrid superconducting structures, interesting phenomena and device applications in phase-shifted superconducting systems are presented. In addition, various possibilities for developing electrically and magnetically controllable 0 and π junctions are presented; these possibilities are expected to be useful for future devices.

We present a concept of an advanced rapid single-flux-quantum (RSFQ) logic circuit family using the combination of 0-shifted and π-shifted Josephson junctions. A π-shift in the current-phase relationship can be obtained in several types of Josephson junctions, such as Josephson junctions containing a ferromagnet barrier layer, depending on its thickness and temperature. We use a superconducting quantum interference devices composed of a pair of 0- and π-shifted Josephson junctions (0-π SQUIDs) as a basic circuit element. Unlike the conventional RSFQ logic, bistability is obtained by spontaneous circular currents without using a large superconductor loop, and the state can be flipped by smaller driving currents. These features lead to energy- and/or space-efficient logic gates. In this paper, we show several example circuits where we represent signals by flips of the states of a 0-π SQUID. We obtained successful operation of the circuits from numerical simulation.

Arterial spin labeling (ASL) is a non-invasive magnetic resonance imaging (MRI) method that can provide direct and quantitative measurements of cerebral blood flow (CBF) of scanned patients. ASL can be utilized as an imaging modality to detect Alzheimer's disease (AD), as brain atrophy of AD patients can be revealed by low CBF values in certain brain regions. However, partial volume effects (PVE), which is mainly caused by signal cross-contamination due to voxel heterogeneity and limited spatial resolution of ASL images, often prevents CBF in ASL from being precisely measured. In this study, a novel PVE correction method is proposed based on pixel-wise voxels in ASL images; it can well handle with the existing problems of blurring and loss of brain details in conventional PVE correction methods. Dozens of comparison experiments and statistical analysis also suggest that the proposed method is superior to other PVE correction methods in AD diagnosis based on real patients data.

This paper provides a prototype neural prosthesis system dedicated to restoring continence and micturition function for patients with lower urinary tract diseases, such as detrusor hyperreflexia and detrusor-sphincter dyssynergia. This system consists of an ultra low-noise electroneurogram (ENG) signal recording module, a bi-phasic electrical stimulator module and a control unit for closed-loop bladder monitoring and controlling. In order to record extremely weak ENG signal from extradural sacral nerve roots, the system provides a programmable gain from 80 dB to 117 dB. By combining of advantages of commercial-off-the-shelf (COTS) electronics and custom designed IC, the recording front-end acquires a fairly low input-referred noise (IRN) of 0.69 μVrms under 300 Hz to 3 kHz and high area-efficiency. An on-chip multi-steps single slope analog-to-digital converter (ADC) is used to digitize the ENG signals at sampling rate of 10 kSPS and achieves an effective number of bits (ENOB) of 12.5. A bi-phasic current stimulus generator with wide voltage supply range (±0.9 V to ±12.5 V) and variable output current amplitude (0-500 μA) is introduced to overcome patient-depended impedance between electrode and tissue electrolyte. The total power consumption of the entire system is 5.61 mW. Recording and stimulation function of this system is switched by control unit with time division multiplexing strategy. The functionality of this proposed prototype system has been successfully verified through in-vivo experiments from dogs extradural sacral nerve roots.

Passive-blind image forensics is a technique that judges whether an image is forged in the absence of watermarking. In image forgery, region duplication is a simple and widely used method. In this paper, we proposed a novel method to detect image region duplication using the spin image which is an intensity-based and rotation invariant descriptor. The method can detect region duplication exactly and is robust to geometric transformations. Furthermore, it is superior to the popular SIFT-based detection method when the copied patch is from smooth background. The experiments have proved the method's effectiveness.

Magnetospinography (MSG) is one of the most promising techniques to detect the nerve activity of spinal cords thanks to its noninvasiveness and high spatial/temporal resolutions. Multichannel superconducting quantum interference device (SQUID) MSG measurement systems optimized for supine subjects have been developed previously and employed in clinical applications in hospitals. Magnetic source analyses of MSG data based on spatial filter techniques reveal the transition of reconstructed current distributions adjacent to the spinal cord. The propagation of the neural signals was noninvasively visualized. The MSG measurements provide significant diagnostic information such as irregularities in the transitions of the reconstructed current distribution and/or considerable decreases in the current intensity at the lesion. Such functional imaging of the spinal cord in addition to conventional neurologic examinations and morphological imaging will be fairly effective in presurgical lesion localizations of the spinal cord.

We recently determined the values of intrinsic spin-orbit (SO) parameters for In0.52Al0.48As/In0.53Ga0.47As(10 nm)/In0.52Al0.48As (InGaAs/InAlAs) quantum wells (QW), lattice-matched to (001) InP, from the weak localization/antilocalization analysis of the low-temperature magneto-conductivity measurements [1]. We have then studied the subband energy spectra for the InGaAs/InAlAs double QW system from beatings in the Shubnikov de Haas (SdH) oscillations. The basic properties obtained here for the double QW system provides useful information for realizing nonmagnetic spin-filter devices based on the spin-orbit interaction [2].

In this paper, we analyze current-voltage characteristics of InSb/AlInSb triple-barrier resonant tunneling diodes (TBRTDs) with spin-splitting under zero magnetic fields. The InSb has very small effective mass, thus we can obtain large spin-splitting by Rashba spin-orbit interaction due to asymmetric InSb/AlInSb quantum wells. In our model, broadening of each resonant tunneling level and spin-splitting energy can be considered to calculate spin-polarized resonant tunneling current.

Silicon Mach-Zehnder interferometric (MZI) waveguide modulator incorporating the n-channel junction field-effect transistor (JFET) as a signal modulation unit was designed, fabricated, and analyzed. The proposed MZI with JFET was designed to operate based on the plasma dispersion effect in the infrared wavelength of 1550 nm. The three different modulation lengths (ML) of 500, 1000, and 2000 µm while keeping the overall MZI length constant at 1.5 cm were set as a general design rule for these 10 µm-wide MZIs under study. When the JFET was operated in an active mode by injecting approximately 50 mA current (Is) to achieve a π phase shift, the modulation efficiency of the device was measured to be η = π /(Is· L) 40π/A-mm. The temporal and frequency response measurements also demonstrate that the respectively rise and fall times measured using a high-speed photoreceiver were in the neighborhood of 8.5 and 7.5 µsec and the 3 dB roll-off frequency (f3 dB) measured was in the excess of 400 kHz.

The number of Web applications handling online transaction is increasing, but verification of the correctness of Web application development has been done manually. This paper proposes a method for modeling, verifying and testing Web applications. In our method, a Web application is modeled using two finite-state automata, i.e., a page automaton which specifies Web page transitions, and an internal state automaton which specifies internal state transitions of the Web application. General properties for checking the Web application design are presented in LTL formulae and they are verified using the model checker Spin. Test cases examining the behavior of the Web application are also generated by utilizing the counterexamples obtained as the result of model checking. We applied our method to an example Web application to confirm its effectiveness.

In this paper, it is shown that our fabricated MTJ of 60180 nm2, which is connected to the MOSFET in series by 3 levels via and 3 levels metal line, can dynamically operate with the programming current driven by 0.14 µm CMOSFET. In our measurement of transient characteristic of fabricated MTJ, the pulse current, which is generated by the MOSFET with an applied pulse voltage of 1.5 V to its gate, injected to the fabricated MTJ connected to the MOSFET in series. By using the current measurement technique flowing in MTJ with sampling period of 10 nsec, for the first time, we succeeded in monitor that the transition speed of the resistance change of 60180 nm2 MTJ is less than 30 ns with its programming current of 500 µA and the resistance change of 1.2 kΩ.

In this paper, we have succeeded in the fabrication of high performance Magnetic Tunnel Junction (MTJ) which is integrated in CMOS circuit with 4-Metal/ 1-poly Gate 0.14 µm CMOS process. We have measured the DC characteristics of the MTJ that is fabricated on via metal of 3rd layer metal line. This MTJ of 60180 nm2 achieves a large change in resistance of 3.52 kΩ (anti-parallel) with TMR ratio of 151% at room temperature, which is large enough for sensing scheme of standard CMOS logic. Furthermore, the write current is 320 µA that can be driven by a standard MOS transistor. As the results, it is shown that the DC performance of our fabricated MTJ integrated in CMOS circuits is very good for our novel spin logic (MTJ-based logic) device.