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

Harmonics from relativistic laser driven plasma surfaces is a prospective high energy attosecond light source in future XUV pump-probe experiments. Among all the schemes, the most efficient and direct way to realize an isolated attosecond pulse is through using a few-cycle laser as the driving pulse. The two goodness criteria: the laser to harmonics energy conversion efficiency and the “purity” of an isolated attosecond pulse are generally determined by a combination of interaction parameters. Through using particle-in-cell simulations and relativistic electron dynamics model analyses, we explain how these two criteria are affected by the laser intensity, incidence angle, carrier-envelope phase, and the plasma scale length. We found that, there exist an optimal plasma scale length and an optimal incidence angle to efficiently generate harmonics and intense attosecond light pulses. When other parameters are fixed, using a moderately intense relativistic laser or using a large incidence angle could result in a higher isolation degree as well as a broader range of controlling parameters to realize an isolated attosecond light pulse.

Isolated attosecond light pulse generation from plasma surfaces at varying laser intensities and incidence angles

A joint cross-dimensional contrastive learning framework for 12-lead ECGs and its heterogeneous deployment on SoC

Erratum: “Gate electrostatic controllability enhancement in nanotube gate all around field effect transistor” [AIP Adv. 13, 065006 (2023)]

Corrigendum to “Comments on ‘Modeling MOSFET surface capacitance behavior under non-equilibrium’” [Solid-State Electronics 50 (2) (2006) 259–262]

This paper, presents a rigorous carrier-based analytic model for the long channel undoped (lightly doped) ultra-thin-body silicon-on-insulator (UTB-SOI) MOSFETs. It is based on the exact solution of the Poisson–Boltzamann equation coupled to the current continuity equation with the back interface oxide layer effect. The developed model is continuous and valid for all UTB-SOI MOSFET operation regions (linear, saturation, sub-threshold and strong inversion region) and traces the transition between different regions. This preliminary model has been verified by comparing with long channel results generated by 2D simulator. The predicted I–V characteristics also show in a good agreement with 2D numerical simulations for all ranges of gate and drain voltages, proving the validity of the analytical model. All these indicate that this model will be an ideal core model for UTB MOSFET compact modelling if the appropriate second-effects such as quantum mechanical effect, doping profile effect, short-channel effects ...

Jin He

Papers

Isolated attosecond light pulse generation from plasma surfaces at varying laser intensities and incidence angles

A joint cross-dimensional contrastive learning framework for 12-lead ECGs and its heterogeneous deployment on SoC

Erratum: “Gate electrostatic controllability enhancement in nanotube gate all around field effect transistor” [AIP Adv. 13, 065006 (2023)]

Corrigendum to “Comments on ‘Modeling MOSFET surface capacitance behavior under non-equilibrium’” [Solid-State Electronics 50 (2) (2006) 259–262]

A rigorous carrier-based analytic model for undoped ultra-thin-body silicon-on-insulator (UTB-SOI) MOSFETs