scholarly journals Influence of Resonances on the Noise Performance of SQUID Susceptometers

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 204 ◽  
Author(s):  
Samantha I. Davis ◽  
John R. Kirtley ◽  
Kathryn A. Moler
Keyword(s):  
Quantum Interference ◽  
Noise Performance ◽  
Superconducting Quantum Interference Device ◽  
Noise Characteristics ◽  
Current Voltage ◽  
Electromagnetic Resonances ◽  
Current Voltage Characteristics ◽  
Local Magnetic Fields ◽  
Scanning Squid ◽  
Further Development

Scanning Superconducting Quantum Interference Device (SQUID) Susceptometry simultaneously images the local magnetic fields and susceptibilities above a sample with sub-micron spatial resolution. Further development of this technique requires a thorough understanding of the current, voltage, and flux ( I V Φ ) characteristics of scanning SQUID susceptometers. These sensors often have striking anomalies in their current–voltage characteristics, which we believe to be due to electromagnetic resonances. The effect of these resonances on the performance of these SQUIDs is unknown. To explore the origin and impact of the resonances, we develop a model that qualitatively reproduces the experimentally-determined I V Φ characteristics of our scanning SQUID susceptometers. We use this model to calculate the noise characteristics of SQUIDs of different designs. We find that the calculated ultimate flux noise is better in susceptometers with damping resistors that diminish the resonances than in susceptometers without damping resistors. Such calculations will enable the optimization of the signal-to-noise characteristics of scanning SQUID susceptometers.

scholarly journals Mechanism for reconfigurable logic in disordered dopant networks

2021 ◽  
Author(s):  
Henri Tertilt ◽  
Jesse Bakker ◽  
Marlon Becker ◽  
Bram de Wilde ◽  
Indrek Klanberg ◽  
...  
Keyword(s):  
Kinetic Monte Carlo ◽  
Logic Gates ◽  
Boolean Logic ◽  
Atomic Scale ◽  
Reconfigurable Logic ◽  
Temperature Dependent ◽  
Current Voltage ◽  
Kinetic Monte Carlo Simulations ◽  
Current Voltage Characteristics ◽  
Further Development

Abstract We present an atomic-scale mechanism based on variable-range hopping of interacting charges enabling reconfigurable logic and nonlinear classification tasks in dopant network processing units in silicon. Kinetic Monte Carlo simulations of the hopping process show temperature-dependent current-voltage characteristics, artificial evolution of basic Boolean logic gates, and fitness-dependent gate abundances in striking agreement with experiment. The simulations provide unique insights in the local electrostatic potential and current flow in the dopant network, showing subtle changes induced by control voltages that set the conditions for the logic operation. These insights will be crucial in the systematic further development of this burgeoning technology for unconventional computing. The establishment of the principles underlying the logic functionality of these devices encourages the exploration and utilization of the same principles in other materials and device geometries.

Non-Destructive Open Fault Isolation in Flip-Chip Devices with Space-Domain Reflectometry

2013 ◽  
Author(s):  
W. Qiu ◽  
M.S. Wei ◽  
J. Gaudestad ◽  
V.V. Talanov
Keyword(s):  
Quantum Interference ◽  
Flip Chip ◽  
Time Domain Reflectometry ◽  
Fault Isolation ◽  
Superconducting Quantum Interference Device ◽  
Isolation Method ◽  
Space Domain ◽  
Open Faults ◽  
Scanning Squid ◽  
Non Destructive

Abstract Space-domain reflectometry (SDR) utilizing scanning superconducting quantum interference device (SQUID) microscopy is a newly developed non-destructive failure analysis (FA) technique for open fault isolation. Unlike the conventional open fault isolation method, time-domain reflectometry (TDR), scanning SQUID SDR provides a truly two-dimensional physical image of device under test with spatial resolution down to 30 μm [1]. In this paper, the SQUID SDR technique is used to isolate dead open faults in flip-chip devices. The experimental results demonstrate the capability of SDR in open fault detection

A New Methodology for Electrical Debugging Short in Packages with the Modified Daisy-Chain Die

2007 ◽  
Author(s):  
Steve K. Hsiung ◽  
Kevan V. Tan ◽  
John Soopikian
Keyword(s):  
Quantum Interference ◽  
Stress Testing ◽  
Time Domain Reflectometry ◽  
Superconducting Quantum Interference Device ◽  
Difficult Time ◽  
Reference Device ◽  
Ic Packaging ◽  
Scanning Squid ◽  
Non Destructive ◽  
The Magnetic Field

Abstract Packages with the Modified Daisy-chain (MDC) die have been used increasingly to accelerate reliability stress testing of IC packaging during package development, qualification, and evaluation and reliability monitor programs [1]. Utilizing this approach in essence eliminates chip circuit failure mechanisms. Unlike packages with active die, in packages with the MDC die, when short occurred between two daisy-chain pairs of I/Os, there are four possibilities that can attribute to each pin of the two daisy-chain pairs. That makes the isolation of short failure difficult. Time Domain Reflectometry (TDR) is a well-described technique to characterize package discontinuity (open or short failure). By using a bare package substrate and a reference device, an analyst can characterize the discontinuity and localize it: within the package, the die-package interconnects, or on the die [2]. Scanning SQUID (Superconducting Quantum Interference Device) Microscopy, known as SSM, is a non-destructive technique that detects magnetic fields generated by current. The magnetic field, when converted to current density via Fast Fourier Transform (FFT), is particularly useful to detect shorts and high resistance (HR) defects [3]. In this paper, a new methodology that combines Resistance Analysis, TDR Isolation and SSM Identification for electrical debugging short in packages with the MDC die will be presented. Case studies will also be discussed.

Un-cooled Micro-bolometer with Sandwiched Thermo-sensing Layer Based on Ge Films Deposited by Plasma

2006 ◽  
Vol 910 ◽  
Author(s):  
Andrey Kosarev ◽  
Mario Moreno ◽  
Alfonso Torres ◽  
Roberto Ambrosio
Keyword(s):  
Response Time ◽  
Low Frequency ◽  
Thermal Response ◽  
Thermal Coefficient ◽  
Temperature Dependence Of Conductivity ◽  
Current Voltage ◽  
Thermal Response Time ◽  
Current Voltage Characteristics ◽  
Thermal Coefficient Of Resistance ◽  
Further Development

AbstractWe have fabricated and studied an un-cooled micro-bolometer with thermo-sensing layer sandwiched between two electrodes. The micro-bolometer has “bridge” configuration to provide sufficient thermo isolation of the thermo-sensing layer and is made on the surface of silicon wafer by means of surface micro-machining technique. The support layer of SiN and thermo-sensing layer of a-Ge:H,F have been deposited by low frequency PE CVD. The active area of the thermo-sensing layer is Ab=70x66 μm2. Temperature dependence of conductivity σ(T), current-voltage characteristics I(U), spectral noise density and thermal response time have been measured to characterize operation and to determine main performance characteristics. Activation energy of the thermo-sensing layer was Ea=0.34 eV providing thermal coefficient of resistance α=0.043 K-1. Pixel resistance was in the range Rb=(1÷30)x105 Ohm. Current and voltage responsivities were in the range RI=0.3÷14 AW-1 and RU=(1÷2)x105 VW-1, respectively. The value of detectivity was in the range of D*=(1÷40)x108 cmHz1/2W-1 and response time was τ=100 μs. The characteristics obtained in this micro-bolometer with sandwiched thermo-sensing layer make it promising for further development.

scholarly journals Magnetoneurograhy of an Electrically Stimulated Arm Nerve

2018 ◽  
Vol 4 (1) ◽  
pp. 363-366 ◽  
Author(s):  
Eric Elzenheimer ◽  
Helmut Laufs ◽  
Tilmann Sander-Thömmes ◽  
Gerhard Schmidt
Keyword(s):  
Power Distribution ◽  
Quantum Interference ◽  
Spectral Power ◽  
Signal Strength ◽  
Frequency Range ◽  
Superconducting Quantum Interference Device ◽  
Spectral Power Distribution ◽  
High Interest ◽  
Averaging Time ◽  
Further Development

AbstractFor further development and optimization of novel uncooled magnetoelectric (ME) sensors, a better understanding of spectral power distribution and signal strength of nerve signals is of high interest. For obtaining information on these signal properties, Superconducting Quantum Interference Device (SQUID) measurements were performed at the Physikalisch-Technische Bundesanstalt (PTB) in Berlin. Signal amplitudes were subject-dependent and ranged from 17 fT to 60 fT in a frequency range from 100 Hz to 1 kHz. The required SQUID averaging time was in the range of minutes, while for current ME sensors significantly longer averaging times are expected to be necessary.

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