Shot-noise Fano factor as a probe of Majorana localized states in p-wave superconductors

2008 ◽  
Vol 403 (5-9) ◽  
pp. 994-995
Author(s):  
C.J. Bolech ◽  
E. Demler
Keyword(s):  
Shot Noise ◽  
Fano Factor ◽  
Localized States ◽  
P Wave

SHOT NOISE SUPPRESSION IN INDIVIDUAL AND SERIES ARRAYS OF MAGNETIC TUNNEL JUNCTIONS

2011 ◽  
Vol 10 (04) ◽  
pp. 381-394 ◽  
Author(s):  
AISHA GOKCE ◽  
RYAN STEARRETT ◽  
E. R. NOWAK ◽  
C. NORDMAN
Keyword(s):  
Shot Noise ◽  
Noise Suppression ◽  
Tunnel Junctions ◽  
Noise Source ◽  
Magnetic Tunnel Junctions ◽  
Fano Factor ◽  
Localized States ◽  
Tunnel Barrier ◽  
In Series ◽  
Shot Noise Suppression

Charge-current shot noise is investigated in single magnetic tunnel junctions and devices having multiple junctions that are connected in series. The ratio of the measured shot noise in single junctions to the expected Poisson value, namely the Fano factor, F, is observed to vary from 1 to well below 0.5. Deviations from F = 1 are attributed to localized states (defects) located in the tunnel barrier or at the interfaces with the magnetic electrodes. For series arrays of junctions, the Fano factor scales inversely with the number (1 ≤ N ≤ 30) of junctions in series, even for junctions exhibiting sub-Poissonian (F < 1) shot noise. The 1/N scaling is consistent with the incoherent tunneling of electrons across junctions and indicates that each junction behaves as an individual noise source. The advantages of incorporating series arrays of magnetic tunnel junctions into devices for magnetic field sensing are discussed.

scholarly journals Enhanced Shot Noise in Resonant Tunneling via Interacting Localized States

2003 ◽  
Vol 91 (13) ◽  
Author(s):  
S. S. Safonov ◽  
A. K. Savchenko ◽  
D. A. Bagrets ◽  
O. N. Jouravlev ◽  
Y. V. Nazarov ◽  
...  
Keyword(s):  
Shot Noise ◽  
Resonant Tunneling ◽  
Localized States

Optimal control of shot noise and Fano factor by external fields

2010 ◽  
Vol 76 (2) ◽  
pp. 309-319 ◽  
Author(s):  
G.-Q. Li ◽  
U. Kleinekathöfer
Keyword(s):  
Optimal Control ◽  
Shot Noise ◽  
Fano Factor ◽  
External Fields

scholarly journals Direct white noise characterization of short-channel MOSFETs

2020 ◽  
Author(s):  
Kenji Ohmori ◽  
Shuhei Amakawa
Keyword(s):  
White Noise ◽  
Shot Noise ◽  
Noise Suppression ◽  
Noise Figure ◽  
Drain Current ◽  
Fano Factor ◽  
Short Channel ◽  
Drain Bias ◽  
Noise Characterization ◽  
First Time

On-wafer evaluation of white thermal and shot noise in nanoscale MOSFETs is demonstrated by directly sensing the drain current under zero- and nonzsero-drain-bias (V<sub>d</sub>) conditions for the first time, without recourse to a hot noise source, commonly needed in noise figure measurement. The dependence of white noise intensity on the drain bias clearly shows thermal noise at V<sub>d</sub>=0 V and shot noise at V<sub>d</sub>>0 V with its gate-bias-dependent suppression. An empirical expression for the Fano factor (shot-noise suppression factor) that is well-behaved even at V<sub>d</sub>=0V exactly and suitable for measurement-based evaluation is proposed. The direct measurement approach could allow more accurate and predictive noise modeling of RF MOSFETs than has conventionally been possible.

scholarly journals Physics-Informed Neural Network for High Frequency Noise Performance in Quasi-Ballistic MOSFETs

Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2219
Author(s):  
Jonghwan Lee
Keyword(s):  
Neural Network ◽  
Shot Noise ◽  
High Frequency ◽  
Equivalent Circuit Model ◽  
Tunneling Current ◽  
Fano Factor ◽  
Channel Noise ◽  
Frequency Noise ◽  
Noise Performance ◽  
Noise Sources

A physics-informed neural network (PINN) model is presented to predict the nonlinear characteristics of high frequency (HF) noise performance in quasi-ballistic MOSFETs. The PINN model is formulated by combining the radial basis function-artificial neural networks (RBF-ANNs) with an improved noise equivalent circuit model, including all the noise sources. The RBF-ANNs are utilized to model the thermal channel noise, induced gate noise, correlation noise, as well as the shot noise, due to the gate and source-drain tunneling current through the potential barriers. By training a spatial distribution of the thermal channel noise and a Fano factor of the shot noise, underlying physical theories are naturally embedded into the PINN model as prior information. The PINN model shows good capability of predicting the noise performance at high frequencies.

Suppression and enhancement of shot noise in mesoscopic transport through localized states

2003 ◽  
Author(s):  
Alex K. Savchenko ◽  
Sergey S. Safonov ◽  
Sergei H. Roshko ◽  
Dmitrii A. Bagrets ◽  
Oleg N. Jouravlev ◽  
...  
Keyword(s):  
Shot Noise ◽  
Localized States ◽  
Mesoscopic Transport

PHOTON SHOT NOISE

1999 ◽  
Vol 13 (11) ◽  
pp. 337-347 ◽  
Author(s):  
C. W. J. BEENAKKER ◽  
M. PATRA
Keyword(s):  
Shot Noise ◽  
Signal To Noise Ratio ◽  
Random Medium ◽  
Fano Factor ◽  
Incident Radiation ◽  
Reduction Factor ◽  
Recent Theory ◽  
Noise Power ◽  
The One ◽  
Bose Einstein

A recent theory is reviewed for the shot noise of coherent radiation propagating through a random medium. The Fano factor [Formula: see text] (the ratio of the noise power and the mean transmitted current) is related to the scattering matrix of the medium. This is the optical analogue of Büttiker's formula for electronic shot noise. Scattering by itself has no effect on the Fano factor, which remains equal to 1 (as for a Poisson process). Absorption and amplification both increase the Fano factor above the Poisson value. For strong absorption [Formula: see text] has the universal limit [Formula: see text], with f the Bose–Einstein function at the frequency of the incident radiation. This is the optical analogue of the one-third reduction factor of electronic shot noise in diffusive conductors. In the amplifying case the Fano factor diverges at the laser threshold, while the signal-to-noise ratio [Formula: see text] reaches a finite, universal limit.

scholarly journals Unified Model of Shot Noise in the Tunneling Current in Sub-10 nm MOSFETs

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2759
Author(s):  
Jonghwan Lee
Keyword(s):  
Analytical Model ◽  
Shot Noise ◽  
Tunneling Current ◽  
Fano Factor ◽  
Unified Model ◽  
Analytical Formulation ◽  
Landauer Formula ◽  
Gate Tunneling ◽  
Tunneling Currents ◽  
Ultrathin Oxide

A single unified analytical model is presented to predict the shot noise for both the source-to-drain (SD) and the gate tunneling current in sub-10 nm MOSFETs with ultrathin oxide. Based on the Landauer formula, the model is constructed from the sequential tunneling flows associated with number fluctuations. This approach provides the analytical formulation of the shot noise as a function of the applied voltages. The model performs well in predicting the Fano factor for shot noise in the SD and gate tunneling currents.

scholarly journals Direct white noise characterization of short-channel MOSFETs

2020 ◽  
Author(s):  
Kenji Ohmori ◽  
Shuhei Amakawa
Keyword(s):  
White Noise ◽  
Shot Noise ◽  
Noise Suppression ◽  
Noise Figure ◽  
Drain Current ◽  
Fano Factor ◽  
Short Channel ◽  
Drain Bias ◽  
Noise Characterization ◽  
First Time

On-wafer evaluation of white thermal and shot noise in nanoscale MOSFETs is demonstrated by directly sensing the drain current under zero- and nonzsero-drain-bias (V<sub>d</sub>) conditions for the first time, without recourse to a hot noise source, commonly needed in noise figure measurement. The dependence of white noise intensity on the drain bias clearly shows thermal noise at V<sub>d</sub>=0 V and shot noise at V<sub>d</sub>>0 V with its gate-bias-dependent suppression. An empirical expression for the Fano factor (shot-noise suppression factor) that is well-behaved even at V<sub>d</sub>=0V exactly and suitable for measurement-based evaluation is proposed. The direct measurement approach could allow more accurate and predictive noise modeling of RF MOSFETs than has conventionally been possible.

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