Differential conductance anomaly in ferromagnetic Ni nanocontacts

2004 ◽  
Vol 282 ◽  
pp. 143-146 ◽  
Author(s):  
Koji Sekiguchi ◽  
Masayoshi Shimizu ◽  
Eiji Saitoh ◽  
Hideki Miyajima
Keyword(s):  
Differential Conductance

scholarly journals NanoLEDs for energy-efficient and gigahertz-speed spike-based sub-λ neuromorphic nanophotonic computing

Nanophotonics ◽  
2020 ◽  
Vol 9 (13) ◽  
pp. 4149-4162 ◽  
Author(s):  
Bruno Romeira ◽  
José M. L. Figueiredo ◽  
Julien Javaloyes
Keyword(s):  
Neural Networks ◽  
Energy Efficient ◽  
High Speed ◽  
Dynamic Properties ◽  
Optical Computing ◽  
Differential Conductance ◽  
Rate Equations ◽  
Dynamical Equations ◽  
Electrical Modulation ◽  
High Bandwidth

AbstractEvent-activated biological-inspired subwavelength (sub-λ) photonic neural networks are of key importance for future energy-efficient and high-bandwidth artificial intelligence systems. However, a miniaturized light-emitting nanosource for spike-based operation of interest for neuromorphic optical computing is still lacking. In this work, we propose and theoretically analyze a novel nanoscale nanophotonic neuron circuit. It is formed by a quantum resonant tunneling (QRT) nanostructure monolithic integrated into a sub-λ metal-cavity nanolight-emitting diode (nanoLED). The resulting optical nanosource displays a negative differential conductance which controls the all-or-nothing optical spiking response of the nanoLED. Here we demonstrate efficient activation of the spiking response via high-speed nonlinear electrical modulation of the nanoLED. A model that combines the dynamical equations of the circuit which considers the nonlinear voltage-controlled current characteristic, and rate equations that takes into account the Purcell enhancement of the spontaneous emission, is used to provide a theoretical framework to investigate the optical spiking dynamic properties of the neuromorphic nanoLED. We show inhibitory- and excitatory-like optical spikes at multi-gigahertz speeds can be achieved upon receiving exceptionally low (sub-10 mV) synaptic-like electrical activation signals, lower than biological voltages of 100 mV, and with remarkably low energy consumption, in the range of 10–100 fJ per emitted spike. Importantly, the energy per spike is roughly constant and almost independent of the incoming modulating frequency signal, which is markedly different from conventional current modulation schemes. This method of spike generation in neuromorphic nanoLED devices paves the way for sub-λ incoherent neural elements for fast and efficient asynchronous neural computation in photonic spiking neural networks.

New Approach to Negative Differential Conductance with High Peak-to-Valley Ratio in Silicon

2000 ◽  
Vol 39 (Part 1, No. 4B) ◽  
pp. 2246-2250 ◽  
Author(s):  
Junji Koga ◽  
Celine Vanderstraeten ◽  
Shin-ichi Takagi ◽  
Akira Toriumi
Keyword(s):  
High Peak ◽  
Differential Conductance ◽  
Negative Differential Conductance ◽  
New Approach ◽  
Peak To Valley Ratio

RENORMALIZATION OF POTENTIAL SCATTERING IN A ONE-DIMENSIONAL NON-LUTTINGER LIQUID: CONDUCTION AND X-RAY FERMI-EDGE SINGULARITY

1995 ◽  
Vol 09 (05) ◽  
pp. 249-269
Author(s):  
DONGXIAO YUE
Keyword(s):  
Luttinger Liquid ◽  
Scattered Wave ◽  
Zeeman Splitting ◽  
Electron System ◽  
Potential Scattering ◽  
Differential Conductance ◽  
One Dimensional ◽  
Edge Singularity ◽  
Fermi Edge ◽  
Fermi Edge Singularity

We review some of our recent results on the potential scattering in a weakly interacting one-dimensional(1D) electron gas. The technique we developed is a poor man's renormalization group procedure in the scattered wave basis. This technique can treat the renormalizations of the scattering on the barrier and the scattering between the electrons in a coherent way, and it allows us to find the scattering amplitudes on a localized potential of arbitrary strength for electrons at any energy. The obtained phase shifts are used to study the Fermi-edge singularity in an interacting 1D electron system, where anomalous exponent of the power-law singularity in the vicinity of the edge is found. The transmission coefficient is directly related to the conductance of a 1D channel by the Landauer formula. Simple formulas that describe the conductance at any temperature are derived. In spin-[Formula: see text] systems, the electron–electron backscattering induces renormalizations of the interaction constants, which causes the low-temperature conductance to deviate from the results of the Luttinger liquid theory. In particular, the temperature dependence of the conductance may become nonmonotonic. In the presence of a magnetic field, backscattering gives rise to a peak in the differential conductance at bias equal to the Zeeman splitting.

TEMPERATURE DEPENDENCE OF HIGH FIELD ELECTRON TRANSPORT PROPERTIES IN WURTZITE PHASE GaN FOR DEVICE MODELING

2008 ◽  
Vol 22 (22) ◽  
pp. 3915-3922 ◽  
Author(s):  
A. R. BINESH ◽  
H. ARABSHAHI ◽  
G. R. EBRAHIMI ◽  
M. REZAEE ROKN-ABADI
Keyword(s):  
Electron Transport ◽  
Electric Fields ◽  
Dominant Role ◽  
Electron Velocity ◽  
Differential Conductance ◽  
Device Modeling ◽  
Wurtzite Phase ◽  
Ensemble Monte Carlo ◽  
Electron Transport Properties ◽  
High Electric Fields

An ensemble Monte Carlo simulation has been used to model bulk electron transport at room and higher temperatures as a function of high electric fields. Electronic states within the conduction band valleys at the Γ1, U, M, Γ3 and K are represented by non-parabolic ellipsoidal valleys centred on important symmetry points of the Brillouin zone. The simulation shows that intervalley electron transfer plays a dominant role in GaN in high electric fields leading to a strongly inverted electron distribution and to a large negative differential conductance. Our simulation results have also shown that the electron velocity in GaN is less sensitive to temperature than in other III-V semiconductors like GaAs . So GaN devices are expected to be more tolerant to self-heating and high ambient temperature device modeling. Our steady state velocity-field characteristics are in fair agreement with other recent calculations.

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