Proposal for a nanoscale variable resistor/electromechanical transistor

A nanoscale transistor based on gate-induced stochastic transitions

A nanoscale device consisting of a metal nanowire, a dielectric, and a gate is proposed. A combination of quantum and thermal stochastic effects enable the device to have multiple functionalities, serving alternately as a transistor, a variable resistor, or a simple resistive element with $I-V$ characteristics that can switch between ohmic and non-ohmic. By manipulating the gate voltage, stochastic transitions between different conducting states of the nanowire can be induced, with a switching time as short as picoseconds. With an appropriate choice of dielectric, the transconductance of the d…

SWNT-array resonant MOS transistor

We show that thin horizontal arrays of single wall carbon nanotubes (SWNTs) suspended above the channel of silicon MOSFETs can be used as vibrating gate electrodes. This new class of nano-electromechanical system (NEMS) combines the unique mechanical and electronic properties of SWNTs with an integrated siliconbased motion detection. Its electrical response exhibits a clear signature of the mechanical resonance of SWNTs arrays (120-150 MHz) showing that these thin horizontal arrays behave as a cohesive, rigid and elastic body membrane with a Young modulus in the order of 1-10 GPa and ultra-low…

Pumping properties of the hybrid single-electron transistor in dissipative environment

Pumping characteristics were studied of the hybrid normal-metal/superconductor single-electron transistor embedded in a high-ohmic environment. Two 3 micrometer-long microstrip resistors of CrOx with a sum resistance R=80kOhm were placed adjacent to this hybrid device. Substantial improvement of pumping and reduction of the subgap leakage were observed in the low-MHz range. At higher frequencies 0.1-1GHz, a slowdown of tunneling due to the enhanced damping and electron heating negatively affected the pumping, as compared to the reference bare devices.

Fast measurement of carbon nanotube resonator amplitude with a heterojunction bipolar transistor

Carbon nanotube (CNT) electromechanical resonators have demonstrated unprecedented sensitivities for detecting small masses and forces. The detection speed in a cryogenic setup is usually limited by the CNT contact resistance and parasitic capacitance. We report the use of a heterojunction bipolar transistor (HBT) amplifying circuit near the device to measure the mechanical amplitude at microsecond timescales. A Coulomb rectification scheme, in which the probe signal is at much lower frequency than the mechanical drive signal, allows investigation of the strongly non-linear regime. The behavio…

Suspended Carbon Nanotube Quantum Wires with Two Gates

Suspended single-walled carbon nanotube devices comprised of high quality electrical contacts and two electrostatic gates per device are obtained. Compared to nanotubes pinned on substrates, the suspended devices exhibit little hysteresis related to environmental factors and manifest as cleaner Fabry-Perot interferometers or single electron transistors. The high-field saturation currents in suspended nanotubes related to optical phonon or zone boundary phonon scattering are significantly lower due to the lack of efficient heat sinking. The multiple gate design may also facilitate future invest…

Suspended graphene devices with local gate control on an insulating substrate

We present a fabrication process for graphene-based devices where a graphene monolayer is suspended above a local metallic gate placed in a trench. As an example we detail the fabrication steps of a graphene field-effect transistor. The devices are built on a bare high-resistivity silicon substrate. At temperatures of 77~K and below, we observe the field-effect modulation of the graphene resistivity by a voltage applied to the gate. This fabrication approach enables new experiments involving graphene-based superconducting qubits and nano-electromechanical resonators. The method is applicable t…

High Q electromechanics with InAs nanowire quantum dots

In this report, we study electromechanical properties of a suspended InAs nanowire (NW) resonator. At low temperatures, the NW acts as the island of a single electron transistor (SET) and we observe a strong coupling between electrons and mechanical modes at resonance; the rate of electron tunneling is approximately 10 times the resonant frequency. Above and below the mechanical resonance, the magnitude of Coulomb peaks is different and we observe Fano resonance in conductance due to the interference between two contributions to potential of the SET. The quality factor ($Q$) of these devices i…

Digital and FM demodulation of a doubly-clamped single wall carbon nanotube oscillator: towards a nanotube cell phone

Electromechanical resonators are a key element in radio-frequency telecommunications devices and thus new resonator concepts from nanotechnology can readily find important industrial opportunities. In this paper, we report the successful experimental realization of AM, FM and digital demodulation with suspended single wall carbon nanotube resonators in the field effect transistor configuration. The crucial role played by the mechanical resonance in demodulation is clearly demonstrated. The FM technique is shown to lead to the suppression of unwanted background signals and the reduction of nois…

原子精度先进制造直接集成到硅制造工艺中段

Direct integration of atomic precision advanced manufacturing into middle-of-line silicon fabrication

本文提出一种结合溅射、退火和硬掩模的APAM工艺，可集成于晶体管制造中段，保留超高掺杂密度而牺牲原子精度，实验证明仅增加电阻不影响晶体管，为APAM进入制造环境铺路。

Gate-modulated thermopower of disordered nanowires: II. Variable-range hopping regime

We study the thermopower of a disordered nanowire in the field effect transistor configuration. After a first paper devoted to the elastic coherent regime (Bosisio R., Fleury G. and Pichard J.-L. 2014 \textit{New J. Phys.} \textbf{16} 035004), we consider here the inelastic activated regime taking place at higher temperatures. In the case where charge transport is thermally assisted by phonons (Mott Variable Range Hopping regime), we use the Miller-Abrahams random resistor network model as recently adapted by Jiang et al. for thermoelectric transport. This approach previously used to study the…