There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

An introduction to heat transfer

International Technology Roadmap for Semiconductors 2003の要求清浄度について － シリコンウエハ表面と雰囲気環境に要求される清浄度, 分析方法の現状について －

The stability of two-dimensional (2D) layers and membranes is subject of a long standing theoretical debate. According to the so called Mermin-Wagner theorem, long wavelength fluctuations destroy the long-range order for 2D crystals. Similarly, 2D membranes embedded in a 3D space have a tendency to be crumpled. These dangerous fluctuations can, however, be suppressed by anharmonic coupling between bending and stretching modes making that a two-dimensional membrane can exist but should present strong height fluctuations. The discovery of graphene, the first truly 2D crystal and the recent experimental observation of ripples in freely hanging graphene makes these issues especially important. Beside the academic interest, understanding the mechanisms of stability of graphene is crucial for understanding electronic transport in this material that is attracting so much interest for its unusual Dirac spectrum and electronic properties. Here we address the nature of these height fluctuations by means of straightforward atomistic Monte Carlo simulations based on a very accurate many-body interatomic potential for carbon. We find that ripples spontaneously appear due to thermal fluctuations with a size distribution peaked around 70 \AA which is compatible with experimental findings (50-100 \AA) but not with the current understanding of stability of flexible membranes. This unexpected result seems to be due to the multiplicity of chemical bonding in carbon.

Intrinsic ripples in graphene

Magnetocaloric effect: From materials research to refrigeration devices

An analytic potential-based model for the undoped surrounding-gate MOSFETs is derived in the paper. The model is obtained from rigorously solving Poisson equation together with the drain-current formulation equivalent to Pao-Sah's double integral that is previously proposed for long-channel bulk MOSFETs. The model consists of an analytic drain-current equation that accounts for both drift and diffusion current components in terms of the potential at the oxide silicon interface and the silicon center of device body evaluated at the source and drain terminals. The model gives a fully self-consistent physical description for the channel potential, charge, and current that is valid for the subthreshold, linear, and saturation regions. The validity of the proposed model has been verified by extensive comparison with the exact numerical integrations and 2-D numerical simulation, which demonstrates model accuracy and prediction capability.

An Analytic Potential-Based Model for Undoped Nanoscale Surrounding-Gate MOSFETs

A non-charge-sheet based analytic theory for undoped symmetric double-gate MOSFETs is presented in this paper. The formulation is based on the exact solution of the Poisson’s equation to solve for electron concentration directly rather than relying on the surface potential alone. Therefore, carrier distribution in the channel away from the surface is also taken care, giving a non-charge-sheet model compatible with the classical Pao-Sah model. The formulated model has an analytic form that does not need to solve for the transcendent equation as in the conventional surface potentials or Pao-Sah formulation. The validity of the model has also been demonstrated by extensive comparison with AMD double-gate MOSFET’s data

A non-charge-sheet analytic theory for undoped symmetric double-gate MOSFETs from the exact solution of Poisson's equation using SPP approach

Neural networks are powerful computation tools for mimicking the human brain to solve realistic problems. Since spiking neural networks are a type of brain-inspired network, called the novel spikin...

Monitor-Based Spiking Recurrent Network for the Representation of Complex Dynamic Patterns.

A new analytical method to design the multiple floating field limiting rings (MFFLRs) system of power devices has been proposed in this paper. This analytic method starts from our previous single field limiting theory, extending to predict the MFFLRs’s electric field and voltage distribution between multiple rings. Based on this method result, the effects of the junction depth and ring spacing on the voltage and edge field profile have been analyzed. A new simple procedure to predict the optimal spacing and the maximum breakdown voltage has also been presented. The excellent agreement with experimental and numerical analysis proves the applicability of the method presented in optimization of the MFFLRs of the power devices.

A new analytic method to design multiple floating field limiting rings of power devices

A numerical study on the characteristics of dual-material gate nanowire tunnel field-effect transistor (DMG-NTFET) is presented using 3-D TCAD simulations in this paper Compared with the single-material gate tunnel field-effect transistor (SMG-NTFET), the numerical simulation results demonstrate that the DMG-NTFET has lower leakage current I OFF with a negligible loss of I ON  Moreover, the impact of two gates' work function difference on the DMG-NTFET ON/OFF current ratio, transconductance (G m ) and DIBL effects is studied, and the effect of control gate length on the I ON and I OFF is demonstrated Finally, the optimization design of the work function difference and the control gate length for the DMG-NTFET is discussed

Jin He

Papers

An Analytic Potential-Based Model for Undoped Nanoscale Surrounding-Gate MOSFETs

A non-charge-sheet analytic theory for undoped symmetric double-gate MOSFETs from the exact solution of Poisson's equation using SPP approach

Monitor-Based Spiking Recurrent Network for the Representation of Complex Dynamic Patterns.

A new analytic method to design multiple floating field limiting rings of power devices

Numerical study on dual material gate nanowire tunnel field-effect transistor