Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 0705.2082

Plasma effects in a micromachined floating-gate high-electron-mobility transistor

Y. Hu·I. Hagiwara·I. Khmyrova·M. Ryzhii·V. Ryzhii·M. S. Shur
View original source ↗Read source document ↗Export metadata ↓

Abstract

We study plasma effects in a micromachined high-electron mobility transistor (HEMT) with the microcantilever serving as the gate using the developed a model. The model accounts for mechanical motion of the microcantilever and spatio-temporal variations (plasma effects) of the two-dimensional electron gas(2DEG) system in the transistor channel. The microcantilever mechanical motion is described in the point-mass approximation. The hydrodynamic electron transport model is used to describe distributed electron plasma phenomena in the 2DEG system. Using the developed model, we calculated the response function characterizing the amplitude microcantilever oscillations and the output electric signal as functions of the signal frequency and the bias voltage for the devices with different parameters. We find the voltage dependences of the frequency of the mechanical resonance and its damping. In particular, it is demonstrated that the amplitudes of the mechanical oscillations and output electric signal exhibit pronounced maxima at the bias voltages close to the voltage of the 2DEG channel depletion followed by a steep drop with further increase in the bias voltage.

Explore related subjects

cond-mat.mes-hall

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Y. Hu, I. Hagiwara, I. Khmyrova, M. Ryzhii, V. Ryzhii, M. S. Shur. 2007-05-17. Plasma effects in a micromachined floating-gate high-electron-mobility transistor. https://arxiv.org/abs/0705.2082

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Electrostatic edge effects versus edge doping in graphene nanoribbons: a scanning gate microscopy and modelling study

The charge neutrality point (CNP) of graphene nanoribbons (GNRs) patterned by oxygen plasma etching moves towards zero as the ribbon narrows and, on 300 nm SiO2, changes sign below a crossover width of ~ 50 nm: an observation previously attributed to n-type edges surrounding a p-type bulk. We test this edge-doping hypothesis in three ways. First, finite element modelling of complete GNR transistors with uniform doping shows that fringing of the gate field at the edges reproduces the trend of the measured CNP with width down to ~ 50nm without any edge doping, while producing a bias-dependent inversion of the carrier type at the edges that mimics n-type edges in scanned-probe measurements. Second, fitting the CNP of ribbons on 90 nm and 300 nm SiO2 with the gate capacitance of a finite strip, which fixes the electrostatic contribution with no adjustable parameter other than the bulk doping, shows that fringing accounts for most of the width dependence and isolates the remainder as an edge charge. This is acceptor-like (0.24 e/nm per edge) in the present ribbons, which therefore have no n-type edges, and donor-like but small in devices on 300 nm SiO2; no single edge-charge, field-coupled or contact-doping mechanism describes both. Third, scanning gate microscopy finds no edge contrast of the sign expected for n-type edges. The width dependence of the CNP is therefore predominantly electrostatic, and n-type edges are not an intrinsic consequence of oxygen-plasma etching. A design map shows that fringing dominates the width dependence whenever the gate dielectric is thicker than 30-50 nm, whereas in scaled high-K transistors, edge charge dominates and would shift the threshold voltage of a 10 nm ribbon by ~ 0.1-0.15 V. Fitting the CNP versus width with the strip capacitance provides a simple test for edge doping in any gated two-dimensional nanostructure

cond-mat.mes-hall↗
arXiv2026

Parity-driven RKKY decoupling and anomalous $1/R$ Dzyaloshinskii-Moriya interaction in odd-parity magnets

Unconventional odd-parity magnets, characterized by an odd-parity momentum-dependent spin splitting, offer a fundamentally distinct paradigm for non-collinear spintronics. Here, we theoretically investigate the Ruderman-Kittel-Kasuya-Yosida indirect exchange in two-dimensional odd-parity magnets subjected to Rashba spin-orbit coupling. Using an analytical real-space Green's function formalism, we uncover a parity-driven spatial decoupling in the magnetic response. Because of the odd-parity exchange field, the out-of-plane Ising interaction is structurally insulated from the macroscopic magnetic modulation, oscillating isotropically at the shifted Fermi wavevector. Conversely, the in-plane Heisenberg components exhibit pronounced, directionally tunable spatial beating. Beyond collinear exchange, the hybridized bands generate a highly tunable, three-component Dzyaloshinskii-Moriya interaction alongside symmetric off-diagonal anisotropies. We reveal that the out-of-plane chiral twisting is driven by the massive, nonrelativistic momentum shift, while the in-plane chiral components are relativistic. Furthermore, the competition between the nodal geometry and the Rashba gap drives an anomalous, dimension-reducing crossover, in which the in-plane chiral components follow a 1D-like $1/R$ spatial decay along the nodal lines over an extended intermediate-distance window before ultimately recovering the conventional 2D $1/R^2$ asymptote. We demonstrate that these findings hold universally across the odd-parity class by explicitly generalizing our framework to $f$-wave magnets. Finally, numerical tight-binding calculations verify the striking robustness of this parity-driven decoupling against both scalar and random magnetic exchange disorder. These findings establish odd-parity magnets as promising platforms for engineering robust, directionally tunable non-collinear spin textures.

cond-mat.mes-hall↗
arXiv2026

Ferroelastic Reversal Magnon Thermal Hall Effect in a Fully Compensated Ferrimagnet

Magnons offer a charge-neutral channel for spin and heat transport, yet reversible and nonvolatile control of their thermal Hall response poses a fundamental challenge in systems with zero net magnetization. Here, we establish ferroelastic switching as an effective route to manipulate magnonic transverse responses in fully compensated ferrimagnets. A minimal Heisenberg-Dzyaloshinskii-Moriya model reveals that ferroelastic switching can re-orientate the lattice anisotropy, which reconstructs the chirality-resolved magnon bands and Berry curvature distribution. Consequently, the two orthogonal fully compensated ferrimagnetic variants related by [C2||C4z] exhibit magnon thermal Hall responses with opposite signs, whereas the response vanishes in the intermediate altermagnetic phase. First-principles calculations further identify monolayer V2SSe as a promising material candidate for realizing the proposed ferroelastic control of transverse magnon transport. Remarkably, ferroelastic switching drives a dual magnonic-electronic band reconstruction, enabling nonvolatile reversal of the magnon thermal Hall effect while producing anisotropic orbital Hall responses and distinct magneto-optical spectra as complementary transport and optical fingerprints. Our findings establish ferroelasticity as an effective route to nonvolatile magnon control and multichannel state identification in zero net magnetization systems.

cond-mat.mes-hall↗