Article
Optics
Jian-Dong Zhang, Chenglong You, Shuai Wang
Summary: This paper investigates the phase sensitivity limits of a Mach-Zehnder interferometer with specific scenarios and optimal single-mode input choices, as well as the effects of several realistic factors on phase sensitivity.
Article
Optics
Nicola Coluccelli, Giovanni Cichelli, Paolo Laporta, Giulio Cerullo
Summary: We propose a system that combines a high-energy femtosecond ytterbium laser, an optical parametric amplifier, and a photonic crystal hollow core fiber compressor for coherent anti-Stokes Raman scattering spectroscopy. The use of the compressor allows for matching the duration of the Stokes pulse to that of the pump pulse, resulting in improved excitation efficiency. Experimental results and a theoretical model are presented to quantify the expected sensitivity improvement. The system is successfully demonstrated for detecting bacterial spores on a surface with a single laser shot, achieving an unprecedented signal-to-noise ratio.
Article
Engineering, Electrical & Electronic
Yasmine Hawwari, Jerome Antoni, Hugo Andre, Yosra Marnissi, Dany Abboud, Mohammed El-Badaoui
Summary: This article presents a practical solution to the problem of detecting spectral peaks in nonuniform spectra. A robust probabilistic approach is applied, where the histogram of trimmed spectral data is fitted with a truncated Gamma distribution. The estimated distribution parameters are used to derive a threshold through a hypothesis test. The proposed approach is robust as it formulates the distribution without peaks, regardless of the number of peaks in the spectral data. The authors also suggest a preprocessing step to handle nonuniform spectra, and the methodology is validated using simulated and experimental signals.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2022)
Article
Physics, Applied
Pui Q. Yang
Summary: A unified model of shot and Johnson noises is developed for ICIPs, helping to address the confusion between the two noise sources in evaluating detectivities. General yet concise expressions are derived for evaluating the noise characteristics and detectivity of ICIPs, as well as the signal current and photon noise. These derivations contribute to a better understanding of the noise characteristics in ICIPs and other photodetectors.
APPLIED PHYSICS LETTERS
(2022)
Article
Computer Science, Artificial Intelligence
Shafin Rahman, Salman Khan, Nick Barnes
Summary: This article proposes a novel loss function called polarity loss to improve the visual-semantic alignment in zero-shot object detection models. By refining semantic embeddings and maximizing the gap between positive and negative predictions, the approach achieves better feature representation and object discrimination, leading to significant performance improvements on multiple datasets.
IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS
(2022)
Article
Computer Science, Artificial Intelligence
Haoang Chi, Shengang Li, Wenjing Yang, Long Lan
Summary: In wildly FDA (WFDA), classifiers are trained with noisy labeled data from source domain and few labeled data from target domain. To address the issue of label noise in the source domain, a robust quadruple adaptation network (QAN) is proposed as a concise and effective solution. Experiments demonstrate that under WFDA, QAN outperforms existing baselines.
KNOWLEDGE-BASED SYSTEMS
(2021)
Article
Optics
Sara Meir, Avi Klein, Hamootal Duadi, Eliahu Cohen, Moti Fridman
Summary: Correlated beams play a crucial role in communication and technology, but classical amplifiers can degrade their correlation. In this study, we investigate the impact of amplifiers on correlated beams using a novel measurement system, and demonstrate methods to tailor the correlation after amplification.
Article
Quantum Science & Technology
Lisa Maria Gaechter, Rebekka Garreis, Jonas Daniel Gerber, Max Josef Ruckriegel, Chuyao Tong, Benedikt Kratochwil, Folkert Kornelis de Vries, Annika Kurzmann, Kenji Watanabe, Takashi Taniguchi, Thomas Ihn, Klaus Ensslin, Wister Wei Huang
Summary: We demonstrate two different experimental approaches to measure the decay times of excited states in bilayer graphene quantum dots, and obtained long decay times. We also introduce a new method using a capacitively coupled charge sensor to study the time dynamics of the excited state.
Article
Acoustics
Matthew de Brett, Tore Butlin, Luis Andrade, Ole M. Nielsen
Summary: This paper investigates the impact of nonlinear vibration transmission through car suspensions on road noise control, and the experiments demonstrate that hydraulic dampers in cars have strong nonlinear characteristics at low frequencies.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Physics, Multidisciplinary
Simon Grall, Shuo Li, Laurent Jalabert, Soo Hyeon Kim, Arnaud Chovin, Christophe Demaille, Nicolas Clement
Summary: This article introduces a formalism to describe the electrochemical shot noise of a redox monolayer, which has been experimentally confirmed at room temperature in a liquid environment. The proposed method, performed at equilibrium, eliminates parasitic capacitance and increases sensitivity, allowing for quantitative information about electron coupling, dispersion, and the number of molecules. Unlike solid-state physics, the homogeneity in energy levels and transfer rates in the monolayer results in a Lorentzian spectrum. This study opens up possibilities for quantum transport research in liquid environments at room temperature and highly sensitive measurements for bioelectrochemical sensors.
PHYSICAL REVIEW LETTERS
(2023)
Article
Optics
Pavel A. Cheremkhin, Nikolay N. Evtikhiev, Vitaly V. Krasnov, Vladislav G. Rodin, Rostislav S. Starikov
Summary: This study focuses on analyzing the impact of the main noise components of digital cameras in digital holography on reconstructed images, obtaining analytical equations for estimating signal-to-noise ratio, and allowing for the pre-estimation of the camera noise effect on reconstructed images before experiments.
OPTICS AND LASERS IN ENGINEERING
(2021)
Article
Computer Science, Artificial Intelligence
Haoran Li, Chun-Mei Feng, Yong Xu, Tao Zhou, Lina Yao, Xiaojun Chang
Summary: The goal of this study is to improve the detection performance of unseen classes in camouflaged object detection (COD). A new zero-shot COD framework is proposed, which includes a Dynamic Graph Searching Network (DGSNet) and a Camouflaged Visual Reasoning Generator (CVRG). The framework utilizes a dynamic searching strategy for graph reasoning and aims to detect camouflaged objects more effectively.
IEEE TRANSACTIONS ON IMAGE PROCESSING
(2023)
Article
Nanoscience & Nanotechnology
Han Li, Zhao Zhang, Luhan Zu, Yongcun Hao, Honglong Chang
Summary: This paper outlines the design of a novel mode-localized electric current sensor based on a mechanically sensitive element of weakly coupled resonator systems. The sensor converts the test current to voltage through a silicon shunt resistor, causing a stiffness perturbation to one resonator. The mode-localization phenomenon alters the energy distribution, and the sensor has a sensitivity of 567/A, a noise floor of 69.3 nA/root Hz, a resolution of 183.6 nA, and a bias instability of 81.6 nA.
MICROSYSTEMS & NANOENGINEERING
(2022)
Article
Engineering, Multidisciplinary
Mohsen Mousavi, Damien Holloway, J. C. Olivier, Amir H. Gandomi
Summary: This paper explores the advantages of using Variational Mode Decomposition (VMD) in detecting local damage on beam type structures subjected to a sprung mass. By introducing a new damage sensitive feature (DSF), it enhances peaks at the damage positions while suppressing peaks at other locations, demonstrating superior performance compared to the well-known Empirical Mode Decomposition (EMD) method.
Article
Acoustics
Aryan Singh, Keegan J. Moore
Summary: This research presents a signal denoising method based on empirical mode decomposition (EMD) and linear combinations of intrinsic mode functions (IMFs). The proposed method effectively addresses the issue of mode mixing and optimizes the linear combination to minimize noise and maximize information in the denoised signal. The method is demonstrated on two applications and compared to existing denoising approaches, showing better performance.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Review
Chemistry, Multidisciplinary
Ferdinand Evers, Amnon Aharony, Nir Bar-Gill, Ora Entin-Wohlman, Per Hedegard, Oded Hod, Pavel Jelinek, Grzegorz Kamieniarz, Mikhail Lemeshko, Karen Michaeli, Vladimiro Mujica, Ron Naaman, Yossi Paltiel, Sivan Refaely-Abramson, Oren Tal, Jos Thijssen, Michael Thoss, Jan M. van Ruitenbeek, Latha Venkataraman, David H. Waldeck, Binghai Yan, Leeor Kronik
Summary: This article provides a critical overview of the theory of the chirality-induced spin selectivity (CISS) effect and reviews its applications in electron processes. It discusses the latest developments in the understanding of the CISS effects in electron transmission, electron transport, and chemical reactions, and identifies the remaining challenges and research opportunities.
ADVANCED MATERIALS
(2022)
Article
Physics, Multidisciplinary
F. J. Matute-Canadas, C. Metzger, Sunghun Park, L. Tosi, P. Krogstrup, J. Nygard, M. F. Goffman, C. Urbina, H. Pothier, A. Levy Yeyati
Summary: In this study, microwave spectroscopy of an InAs nanowire between superconducting contacts implementing a finite-length, multichannel Josephson weak link was performed. Additional transitions indicating Coulomb interactions were identified, providing a qualitative understanding of the rich Andreev spectra through a combination of experimental measurements and model calculations.
PHYSICAL REVIEW LETTERS
(2022)
Correction
Physics, Multidisciplinary
Sujoy Karan, Haonan Huang, Ciprian Padurariu, Bjorn Kubala, Andreas Theiler, Annica M. Black-Schaffer, Gonzalo Morras, Alfredo Levy Yeyati, Juan Carlos Cuevas, Joachim Ankerhold, Klaus Kern, Christian R. Ast
Article
Physics, Multidisciplinary
Sujoy Karan, Haonan Huang, Ciprian Padurariu, Bjoern Kubala, Andreas Theiler, Annica M. Black-Schaffer, Gonzalo Morras, Alfredo Levy Yeyati, Juan Carlos Cuevas, Joachim Ankerhold, Klaus Kern, Christian R. Ast
Summary: This study demonstrates the reversal of supercurrent flow from 0 to pi in a Josephson junction by continuously changing the impurity-superconductor coupling at the atomic scale.
Article
Physics, Multidisciplinary
Miguel Alvarado, Alfredo Levy Yeyati
Summary: The study introduces a general method to obtain the boundary Green's function of correlated systems, using a numerical algorithm to circumvent previous analytical constraints. The efficiency and accuracy of the method is demonstrated through analyzing edge features of different models.
Article
Multidisciplinary Sciences
Edwin Herrera, Isabel Guillamon, Victor Barrena, William J. Herrera, Jose Augusto Galvis, Alfredo Levy Yeyati, Jan Rusz, Peter M. Oppeneer, Georg Knebel, Jean Pascal Brison, Jacques Flouquet, Dai Aoki, Hermann Suderow
Summary: Two-dimensional electronic states are often observed at surfaces of wide-band metals, resulting from confinement by nanoscale closed geometries. In this study, we used scanning tunnelling microscopy to investigate atomically flat terraces on the surfaces of a heavy-fermion superconductor, URu2Si2. We observed two-dimensional heavy fermions with quantized energy levels separated by a fraction of a millielectronvolt, suggesting a new route to studying quantum-well states in strongly correlated quantum materials.
Article
Multidisciplinary Sciences
A. Ibabe, M. Gomez, G. O. Steffensen, T. Kanne, J. Nygard, A. Levy Yeyati, E. J. H. Lee
Summary: In this study, we find that measurements of the superconductor-to-normal transition resulting from Joule heating can be used as a powerful spectroscopical tool to characterize hybrid superconductor-semiconductor devices. By applying this technique to junctions in Al-InAs nanowires, we obtain detailed information of each lead independently, including differences in superconducting coherence lengths, inhomogeneous covering of the epitaxial shell, and the inverse superconducting proximity effect, which can serve as a unique fingerprint for each device with applications in data interpretation, device optimization, and disorder analysis. Our work highlights the importance of heating in hybrid devices, an effect that is often overlooked.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Jan M. M. van Ruitenbeek, Richard Korytar, Ferdinand Evers
Summary: By introducing a simple model system, we have found that chirality-induced spin selectivity can be understood as the result of constructive interference of partial waves scattered by the spin-orbit terms. Forward scattering rates are found to be independent of spin, while back scattering is spin dependent over wide energy windows.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Julian Skolaut, Jedrzej Tepper, Federica Galli, Wulf Wulfhekel, Jan M. van Ruitenbeek
Summary: Determining the conductivity of molecular layers is crucial in molecular electronics. We utilized conductive atomic force microscopy to investigate the influence of gold substrate roughness on conductivity variation, finding that substrate roughness plays a crucial role.
BEILSTEIN JOURNAL OF NANOTECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
S. Mojtaba Tabatabaei, David Sanchez, Alfredo Levy Yeyati, Rafael Sanchez
Summary: We discuss a quantum thermal machine that generates power from a thermally driven double quantum dot coupled to normal and superconducting reservoirs. Energy exchange between the dots is mediated by electron-electron interactions. We find that the heat engine efficiency increases with increasing coupling to the superconducting reservoir. The presence of the superconducting gap and the strong energy dependence of the electronic density of states around the gap edges contribute to large efficiencies. The competition between Andreev processes and quasiparticle tunneling is observed in the system. Our results emphasize the importance of both pair tunneling and structured band spectrum for an accurate characterization of the heat engine properties in normal-superconducting coupled dot systems.
Article
Materials Science, Multidisciplinary
W. Dednam, S. Tewari, E. B. Lombardi, J. J. Palacios, J. M. van Ruitenbeek, C. Sabater
Summary: This article studies the dynamic bonding of gold atoms on surfaces under low coordination conditions using low-temperature scanning tunneling microscopy. By conducting experiments with an atomically sharp gold tip and utilizing classical molecular dynamics simulations and density-functional theory calculations, the differences in bonding behavior between different positions are elucidated, as well as providing information on the crystalline classification of the STM tips based on their performance.
Article
Materials Science, Multidisciplinary
G. O. Steffensen, J. C. Estrada Saldana, A. Vekris, P. Krogstrup, K. Grove-Rasmussen, J. Nygard, A. L. Yeyati, J. Paaske
Summary: Direct transport between two opposing sets of YSR subgap states has been demonstrated in a double quantum dot, and the transition between the relaxation regimes has been identified.
Article
Materials Science, Multidisciplinary
Jon Ortuzar, Stefano Trivini, Miguel Alvarado, Mikel Rouco, Javier Zaldivar, Alfredo Levy Yeyati, Jose Ignacio Pascual, Sebastian Bergeret
Summary: In this paper, a theoretical method is presented to calculate the spatial distribution of Yu-Shiba-Rusinov (YSR) bound states in a two-dimensional superconductor with arbitrary Fermi contours (FCs) in the presence of magnetic impurities. The method is based on the Green's function formalism and approximates an arbitrary contour shape to a regular polygon. The accuracy of this approximation is demonstrated by comparing the results with those obtained from an exact numerical calculation. The method is further applied to study the evolution of YSR states in the presence of impurity atoms and compared with experimental results obtained from scanning tunneling microscopy measurements.
Article
Materials Science, Multidisciplinary
C. Hermansen, A. Levy Yeyati, J. Paaske
Summary: In this study, we investigated the frequency-dependent admittance of a phase-biased Josephson junction spanning a magnetic impurity or a spinful Coulomb-blockaded quantum dot. The local magnetic moment led to the emergence of Yu-Shiba-Rusinov bound states, which influenced subgap absorption and inductive response. Modeling the system as a superconducting spin-polarized exchange-cotunnel junction, we calculated the linear current response to an ac bias voltage, considering phase bias, particle-hole symmetry, and source-drain coupling asymmetry. The analysis of the corresponding inductive admittance revealed features consistent with interaction-induced 0-pi transition.
Article
Materials Science, Multidisciplinary
Samuel D. Escribano, Alfredo Levy Yeyati, Ramon Aguado, Elsa Prada, Pablo San-Jose
Summary: This article analyzes the subgap excitations and phase diagram of a quantum dot coupled to a semiconducting nanowire fully wrapped by a superconducting shell. It finds that the induced pairing vanishes under shell fluxoids, causing a level renormalization and pushing subgap levels closer to zero energy.
