Tootfinder

California says Trump's deployment of National Guard violates state sovereignty (Politico)
https://www.politico.com/news/2025/06/09/california-national-guard-lawsuit-gavin-newsom-00394609
http://www.memeorandum.com/250609/p99#a250609p99

Can slow recombination in ordered superconductors explain the excess quasiparticle population?
Eva Gurra, Douglas A. Bennett, Shannon M. Duff, Michael R. Vissers, Joel N. Ullom
https://arxiv.org/abs/2507.03217

Can slow recombination in ordered superconductors explain the excess quasiparticle population?
An excess density of quasiparticles is widely observed in superconducting films. This excess causes performance degradation in a variety of superconducting devices, including decoherence in qubits. In this Letter, we evaluate the hypothesis of [1] that the quasiparticle excess is caused by anomalously slow recombination at low quasiparticle densities due to localization in sub-gap states. We probe the density of states in aluminum and niobium films using current-voltage measurements of tunnel j…

Transmon qubit using Sn as a junction superconductor
Amrita Purkayastha, Amritesh Sharma, Param J. Patel, An-Hsi Chen, Connor P. Dempsey, Shreyas Asodekar, Subhayan Sinha, Maxime Tomasian, Mihir Pendharkar, Christopher J. Palmstr{\o}m, Mo\"ira Hocevar, Kun Zuo, Michael Hatridge, Sergey M. Frolov
https://arxiv.org/abs/2508.04007…

Transmon qubit using Sn as a junction superconductor
Superconductor qubits typically use aluminum-aluminum oxide tunnel junctions to provide the non-linear inductance. Junctions with semiconductor barriers make it possible to vary the superconductor material and explore beyond aluminum. We use InAs semiconductor nanowires coated with thin superconducting shells of beta-Sn to realize transmon qubits. By tuning the Josephson energy with a gate voltage, we adjust the qubit frequency over a range of 3 GHz. The longest energy relaxation time, T1 = 27 …

Stochastic Gradient-Descent Calibration of Pyragas Delayed-Feedback Control for Chaos Suppression in the Sprott Circuit
Adib Kabir, Onil Morshed, Oishi Kabir
https://arxiv.org/abs/2506.06639

Stochastic Gradient-Descent Calibration of Pyragas Delayed-Feedback Control for Chaos Suppression in the Sprott Circuit
This paper investigates chaos control in the Sprott circuit, a minimal electronic system exhibiting complex nonlinear dynamics. Using the third-order nonlinear differential equation from Kaveh Merat paper, we model the circuit and implement delayed feedback control to suppress chaos. Experimental voltage data were extracted from published figures via WebPlotDigitizer. Then we explore two calibration techniques: Minimizing sum of squared errors (SSE), and stochastic gradient descent (SGD) with f…

Sparse Narrow-Band Topology Optimization for Large-Scale Thermal-Fluid Applications
Vladislav Pimanov, Alexandre T. R. Guibert, John-Paul Sabino, Michael Stoia, H. Alicia Kim
https://arxiv.org/abs/2508.04261

Sparse Narrow-Band Topology Optimization for Large-Scale Thermal-Fluid Applications
We propose a fluid-based topology-optimization methodology for convective heat-transfer problems that can manage an extensive number of design variables, enabling the fine geometric features required for the next generation of heat-exchanger designs. Building on the classical Borrvall--Petersson formulation for Stokes flow, we develop a narrow-band optimization algorithm that concentrates computational effort on the fluid--solid interface, where it is most needed. To address the high cost of re…

Towards Long-Range, Battery-less Water Leak Detection: A LoRa-Based Approach
Roshan Nepal, Roozbeh Abbasi, Brandon Brown, Adunni Oginni, Norman Zhou, George Shaker
https://arxiv.org/abs/2507.03649

Towards Long-Range, Battery-less Water Leak Detection: A LoRa-Based Approach
This paper presents a battery-less, self-powered water leak detection system that utilizes LoRa communication for long-range, real-time monitoring. The system harvests hydroelectric energy through a layered stack of conductive nanomaterials and metals, achieving a peak short-circuit current of over 500 mA and 1.65 V open-circuit voltage upon exposure to water. To address LoRa's higher power demands, an energy management subsystem -- comprising a DC-DC boost converter and a 100 mF supercapacitor…

Reimagining Voltage-Controlled Cryogenic Boolean Logic Paradigm with Quantum-Enhanced Josephson Junction FETs
Md Mazharul Islam, Diego Ferrer, Shamiul Alam, Juan P. Mendez, Denis Mamaluy, Wei Pan, Ahmedullah Aziz
https://arxiv.org/abs/2508.00295

Reimagining Voltage-Controlled Cryogenic Boolean Logic Paradigm with Quantum-Enhanced Josephson Junction FETs
The growing demand for ultra low power computing and the emergence of quantum technologies have intensified interest in cryogenic electronics, particularly superconducting devices.Despite their promise, current controlled superconducting components face fundamental challenges in cascadability, limiting their effectiveness in complex logic architectures.To overcome this, recent efforts have focused on developing gate tunable superconducting devices, such as Josephson Junction Field Effect Transi…

Negative differential conductance in triangular molecular assemblies
Chao Li, Vladislav Pokorn\'y, Prokop Hapala, Martin \v{Z}onda, Ping Zhou, Silvio Decurtins, Shi-Xia Liu, Fengqi Song, R\'emy Pawlak, Ernst Meyer
https://arxiv.org/abs/2508.05575

Negative differential conductance in triangular molecular assemblies
We report the creation and characterization of a molecular-scale negative differential conductance (NDC) device by assembling a triangular trimer of 4,5,9,10-tetrabromo-1,3,6,8-tetraazapyrene (TBTAP) molecules on a superconducting Pb(111) substrate. Using low-temperature scanning tunneling spectroscopy, we observe robust NDC behavior manifesting as a decrease in current with increasing voltage between 0.7-0.9 V arising from the interplay of Coulomb blockade and strong inter-molecular capacitive…

This https://arxiv.org/abs/2402.13074 has been replaced.
initial toot: https://mastoxiv.page/@a…

AC Josephson Signatures of the Superconducting Higgs/Amplitude Mode
The Higgs mode in superconductors corresponds to oscillations of the amplitude of the order parameter. While its detection typically entails resonant optical excitation, we present a purely transport-based setup wherein it is excited in a voltage biased Josephson junction. Demonstrating the importance of order parameter dynamics, the interplay of Higgs resonance and Josephson physics enhances the second harmonic Josephson current oscillating at twice the usual Josephson frequency in transparent…

Augmented Physics-Based Li-ion Battery Model via Adaptive Ensemble Sparse Learning and Conformal Prediction
Samuel Filgueira da Silva, Mehmet Fatih Ozkan, Faissal El Idrissi, Marcello Canova
https://arxiv.org/abs/2507.00353

Augmented Physics-Based Li-ion Battery Model via Adaptive Ensemble Sparse Learning and Conformal Prediction
Accurate electrochemical models are essential for the safe and efficient operation of lithium-ion batteries in real-world applications such as electrified vehicles and grid storage. Reduced-order models (ROM) offer a balance between fidelity and computational efficiency but often struggle to capture complex and nonlinear behaviors, such as the dynamics in the cell voltage response under high C-rate conditions. To address these limitations, this study proposes an Adaptive Ensemble Sparse Identif…