scholarly journals Theory of a superconducting artificial neuron for extended backpropagation learning algorism

2018 ◽  
Vol 7 (3.29) ◽  
pp. 170
Author(s):  
Haruna Katayama ◽  
Toshiyuki Fujii ◽  
Noriyuki Hatakenaka
Keyword(s):  
Magnetic Fields ◽  
Josephson Junctions ◽  
Superconducting Devices ◽  
Sigmoid Function ◽  
Fixed Temperature ◽  
Artificial Neuron ◽  
Backpropagation Learning

An artificial neuron using superconducting devices, so-called double SQUID, applicable to the extended backpropagation learning algorism is studied. It is shown that the tunable slope of the sigmoid function required in the algorism can be achieved under the fixed temperature by externally applied magnetic fields threading the ring with two Josephson junctions in the double SQUID.  

scholarly journals Theory of a quantum artificial neuron based on superconducting devices

2018 ◽  
Vol 7 (3.29) ◽  
pp. 150
Author(s):  
Haruna Katayama ◽  
Toshiyuki Fujii ◽  
Noriyuki Hatakenaka
Keyword(s):  
Superconducting Devices ◽  
Quantum Mechanical ◽  
Sigmoid Function ◽  
Artificial Neuron ◽  
Rf Squid ◽  
Double Well Potential ◽  
Flux Qubit ◽  
Coherent Quantum

An artificial neuron using superconducting devices, so-called rf SQUID, working at the quantum-mechanical domain is studied. It is shown that quantum rf SQUID regarded as flux qubit can act as an artificial neuron with sigmoid function generated by coherent quantum-mechanical transitions between wells in double well potential representing rf SQUID.   

scholarly journals Fully in situ Nb/InAs-nanowire Josephson junctions by selective-area growth and shadow evaporation

2021 ◽  
Author(s):  
Pujitha Perla ◽  
H. Aruni Fonseka ◽  
Patrick Zellekens ◽  
Russell Deacon ◽  
Yisong Han ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Josephson Junctions ◽  
Quantum Circuits ◽  
Selective Area Growth ◽  
Selective Area ◽  
Area Growth ◽  
Shadow Evaporation ◽  
Superconducting Quantum Circuits

Nb/InAs-nanowire Josephson junctions are fabricated in situ by a special shadow evaporation scheme for the superconducting Nb electrode. The junctions are interesting candidates for superconducting quantum circuits requiring large magnetic fields.

Arrays of resistively shunted Josephson junctions in magnetic fields

1993 ◽  
Vol 48 (1) ◽  
pp. 322-332 ◽  
Author(s):  
Seunghwan Kim ◽  
M. Y. Choi
Keyword(s):  
Magnetic Fields ◽  
Josephson Junctions

Dynamical Properties of Weakly Coupled Josephson Systems

1990 ◽  
Vol 195 ◽  
Author(s):  
K. H. Lee ◽  
T.-K. Xia ◽  
D. Stroud
Keyword(s):  
High Temperature ◽  
Magnetic Fields ◽  
Harmonic Generation ◽  
Finite Temperature ◽  
Josephson Junctions ◽  
High Temperature Superconductors ◽  
Dynamical Behavior ◽  
Critical Currents ◽  
Weakly Coupled ◽  
Dynamical Properties

ABSTRACTWe review recent work on the dynamical behavior of coupled resistively-shunted Josephson junctions, with emphasis on our own calculations. We present a model which allows for the inclusion of finite temperature, disorder, d.c. and a. c. applied currents, and applied magnetic fields. We discuss applications to (a) calculations of critical currents and IV characteristics; (b) harmonic generation and microwave absorption by finite clusters of Josephson junctions; (c) critical energies for vortex depinning; and (d) quantized voltage plateaus in arrays subjected to combined d.c. and a. c. currents. Possible connections to the behavior of granular high-temperature superconductors are briefly discussed.

Low-error approximation of artificial neuron sigmoid function and its derivative

2009 ◽  
Vol 45 (21) ◽  
pp. 1082 ◽  
Author(s):  
A. Armato ◽  
L. Fanucci ◽  
G. Pioggia ◽  
D. De Rossi
Keyword(s):  
Sigmoid Function ◽  
Artificial Neuron

CRITICAL CURRENT DEPENDENCE OF STACKED JOSEPHSON JUNCTIONS DC SQUID IN Bi2Sr2CaCu2O8+Δ

2007 ◽  
Vol 21 (18n19) ◽  
pp. 3270-3273 ◽  
Author(s):  
SANG-JAE KIM
Keyword(s):  
Magnetic Fields ◽  
Critical Current ◽  
Josephson Junctions ◽  
Quantum Interference ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Periodic Modulation ◽  
Superconducting Quantum Interference Device ◽  
Current Dependence ◽  
Loop Area

We investigate critical current (Ic) modulation of stacked Josephson junctions (SJJs) dc superconducting quantum interference device ( dc SQUID) on a Bi 2 Sr 2 CaCu 2 O 8+δ ( Bi -2212) whisker. A coupled SJJs with a completely perforated hole of 0.1 μ m × 0.2 μ m were fabricated by using a 3-D focused-ion-beam (FIB) etching method. Those dc SQUIDs exhibited uniform multi-branch structures and clearly oscillated critical current under external magnetic fields (He). With applying He, the clear periodic modulation patterns of Ic are obtained and well fitted to the calculated value from the loop area of 0.02 μm2.

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