Article
Optics
Sean Ravenhall, Benjamin Yuen, Chris Foot
Summary: A high-flux compact cold-atom source based on a pyramid MOT was developed for portable quantum technology devices, including space-based experiments. By optimizing the aperture size, higher flux was achieved compared to other cold-atom sources using different MOT configurations.
Article
Multidisciplinary Sciences
Chung Chuan Hsu, Remy Larue, Chang Chi Kwong, David Wilkowski
Summary: This research demonstrates a simple and compact approach to laser cooling and trapping of atoms using laser-induced thermal ablation. The technique shows strong potential for applications in quantum technologies such as quantum computing and precision measurements.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Electrical & Electronic
Anirban Kar, Keshari Nandan, Yogesh Singh Chauhan
Summary: Silicon-based cold-source transistors have great potential in energy-efficient logic switches and semiconductor technology node scaling. In this study, we propose a compact model for dual-gate cold-source field-effect transistors (DG-CSFETs) that is charge-based and includes the impacts of small device geometry. The model accurately captures the drain-current behavior and has been verified against quantum transport simulations, making it the first compact model developed for cold-source transistors.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Physics, Applied
Nicolas Vitrant, Sebastien Garcia, Kilian Muller, Alexei Ourjoumtsev
Summary: The ultracompact high-resolution imaging system for cold atoms developed can image cold Rb atoms with approximately 1-mu m resolution over a 100 x 100 mu m(2) field of view. It utilizes an in-vacuum multimode optical fiber and external adaptive optics, allowing for easy rearrangement between absorption and fluorescence imaging modes. This system is ideal for hybrid quantum-engineering platforms where optical access is restricted.
PHYSICAL REVIEW APPLIED
(2021)
Article
Physics, Applied
Sasan Razmkhah, Ali Bozbey, Pascal Febvre
Summary: The research team has designed and successfully fabricated an on-chip compact voltage multiplier to increase the voltage amplitude of SFQ pulses, which is expected to provide a gain of 10 dB for the output signals of SFQ circuits. The circuit is designed using superconductor technology, with lower noise level compared to traditional semiconductor amplifiers, and can operate at higher frequencies.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2021)
Article
Quantum Science & Technology
Samuel L. Jacob, Massimiliano Esposito, Juan M. R. Parrondo, Felipe Barra
Summary: In a collision between a moving particle and a fixed system with internal degrees of freedom, the motion of the particle can act as a work source for the joint internal system, resulting in energy changes that preserve entropy. This opens up interesting perspectives for quantum thermodynamics formulations within scattering theory.
Article
Optics
B. Major, O. Ghafur, K. Kovacs, K. Varju, V Tosa, M. J. J. Vrakking, B. Schuette
Summary: The study demonstrates a concept for a compact intense XUV source based on HHG, focusing on generating high-intensity XUV pulses for exciting opportunities in XUV strong-field and nonlinear optics experiments, XUV-pump XUV-probe spectroscopy, and coherent diffractive imaging of nanoscale structures.
Article
Thermodynamics
Xinyu Ji, Xiang Ma, Xiaoping Yang, Jinjia Wei, Bengt Sunden
Summary: Through experimental study, it was found that nucleate boiling can be suppressed and forced convection heat transfer can be enhanced by increasing the jet velocity. On the micro-pin-finned surface, the heat transfer is greatly intensified due to the increase in surface area and the number of nucleation sites.
APPLIED THERMAL ENGINEERING
(2023)
Article
Mathematics, Applied
Zhilin Li, Kejia Pan
Summary: In this paper, new fourth order compact schemes for Robin and Neumann boundary conditions are developed for boundary value problems of elliptic PDEs in two and three dimensions. These schemes utilize carefully designed undetermined coefficient methods and can be applied to various elliptic PDEs including both flux and linear boundary conditions. The developed schemes are versatile and generally have M-matrices as coefficient matrices, ensuring well-posed problems and convergence of the methods. Examples with large wave numbers and oscillatory solutions are presented to demonstrate the performance of the new schemes.
SIAM JOURNAL ON SCIENTIFIC COMPUTING
(2023)
Article
Food Science & Technology
Jie Tang, Yifeng Zou, Ruhe Xie, Bo Tu, Guanghai Liu
Summary: In this paper, a compact supervisory system is designed to track refrigerated transportation and detect improper practices using temperature data. Through a testbed simulation and machine learning models, the system is able to classify the state of the door and the refrigeration system.
Article
Construction & Building Technology
Shilei Lu, Yang Liu, Yuwei Li, Ran Wang
Summary: This study proposed a multi-dimensional performance-based evaluation method and validated its feasibility through a real case study, which can accurately evaluate the energy and economic efficiency of cold sources.
ENERGY AND BUILDINGS
(2021)
Article
Environmental Sciences
Maria Tenkanen, Aki Tsuruta, Kimmo Rautiainen, Vilma Kangasaho, Raymond Ellul, Tuula Aalto
Summary: Estimates of methane emissions in northern wetlands have large uncertainties, with inversion models being a potentially useful method. However, sparse atmospheric observations can limit the accuracy of these models, highlighting the importance of improving a priori estimates. This study utilizes SMOS satellite data to better capture the seasonality of methane emissions in the northern high latitudes, resulting in a 17% reduction in cold season biospheric emissions compared to previous estimates, partially offset by increased anthropogenic emissions.
Article
Nanoscience & Nanotechnology
Weibin Xie, Qing Wang, Xuan He, Shengwei Fang, Zhichao Yuan, Xianghui Qi, Xuzong Chen
Summary: This study proposes a cold cesium atomic beam source for use in cesium beam atomic clocks. The source utilizes a two-dimensional magneto-optical trap (2D-MOT) with hollow cooling and pushing lights to separate the cooling and pushing functions, resulting in a high-flux cold atomic beam output.
Article
Astronomy & Astrophysics
Takuya Tsutsui, Kipp Cannon, Leo Tsukada
Summary: Multimessenger astronomy is of great interest, with the speed of gravitational wave source localization being crucial for electromagnetic follow-up success. A new rapid compact object collision localization method trade-off accuracy for speed, suitable for fast early location estimates.
Article
Thermodynamics
Noriyuki Watanabe, Takuji Mizutani, Hosei Nagano
Summary: A miniature loop heat pipe (mLHP) has been developed for cooling compact wide bandgap power semiconductors with high heat flux and high allowable operating temperature. The mLHP, consisting of an evaporator, a condenser, and transport tubes, can achieve excellent heat transfer performance using specific materials and cooling methods. The proposed steady-state numerical model is consistent with experimental results, with a relative error of 7%.
ENERGY CONVERSION AND MANAGEMENT
(2021)
Article
Physics, Multidisciplinary
A. Farolfi, A. Zenesini, D. Trypogeorgos, C. Mordini, A. Gallemi, A. Roy, A. Recati, G. Lamporesi, G. Ferrari
Summary: The study successfully achieved effects similar to magnetic junctions using a coherently coupled mixture of ultracold bosonic gases, observing the formation of magnetic interfaces and waves. These results establish ultracold gases as a platform for studying far-from-equilibrium spin dynamics in regimes not easily accessible in solid-state systems.
Article
Optics
Simone Donadello, Valentina Furlan, Ali Gokhan Demir, Barbara Previtali
Summary: The study analyzed the relationship between powder catchment efficiency and deposition height stability, revealing that track height stabilization is associated with a reduction of the powder catchment efficiency. Through a monitoring system and analytical model, it was possible to estimate the highest powder catchment efficiency and regular height in real-time.
OPTICS AND LASERS IN ENGINEERING
(2022)
Correction
Multidisciplinary Sciences
Cecilia Clivati, Alice Meda, Simone Donadello, Salvatore Virzi, Marco Genovese, Filippo Levi, Alberto Mura, Mirko Pittaluga, Zhiliang Yuan, Andrew J. Shields, Marco Lucamarini, Ivo Pietro Degiovanni, Davide Calonico
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Cecilia Clivati, Alice Meda, Simone Donadello, Salvatore Virzi, Marco Genovese, Filippo Levi, Alberto Mura, Mirko Pittaluga, Zhiliang Yuan, Andrew J. Shields, Marco Lucamarini, Ivo Pietro Degiovanni, Davide Calonico
Summary: In this study, the authors use technologies from the optical clocks community to demonstrate a setup for twin-field quantum key distribution (QKD) that extends the coherence times by three orders of magnitude, overcoming the main challenge towards real-world implementation. They develop a solution using interferometry techniques to enable simultaneous key streaming and channel length control, and successfully demonstrate it on a 206 km field-deployed fiber. This technique represents an effective solution for real-world quantum communications.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
R. Cominotti, A. Berti, A. Farolfi, A. Zenesini, G. Lamporesi, I. Carusotto, A. Recati, G. Ferrari
Summary: We experimentally measured the dispersion relation of density and spin collective excitation modes in an elongated two-component superfluid of ultracold bosonic atoms. By utilizing a parametric spectroscopic technique based on external modulation of the transverse confinement frequency, we observed the formation of density and spin Faraday waves. Furthermore, we demonstrated that coherent coupling between the two components breaks the phase symmetry and imparts a finite mass to the spin modes.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Lauritz Klaus, Thomas Bland, Elena Poli, Claudia Politi, Giacomo Lamporesi, Eva Casotti, Russell N. Bisset, Manfred J. Mark, Francesca Ferlaino
Summary: This study investigates the phenomenon of quantized vortices in ultracold gases composed of lanthanide atoms, utilizing manipulation of atoms and rotating external magnetic fields.
Article
Physics, Multidisciplinary
S. Bresolin, A. Roy, G. Ferrari, A. Recati, N. Pavloff
Summary: Close to the demixing transition, the degree of freedom associated with relative density fluctuations of a two-component Bose-Einstein condensate is described by a nondissipative Landau-Lifshitz equation. In the quasi-one-dimensional weakly immiscible case, this mapping surprisingly predicts that a dark-bright soliton should oscillate when subject to a constant force favoring separation of the two components. We propose a realistic experimental implementation of this phenomenon which we interpret as a spin -Josephson effect in the presence of a movable barrier.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
R. Cominotti, A. Berti, C. Dulin, C. Rogora, G. Lamporesi, I. Carusotto, A. Recati, A. Zenesini, G. Ferrari
Summary: This study demonstrates a quantum phase transition from a paramagnetic to a ferromagnetic state in an extended atomic superfluid with a coherent coupling between two internal states. The nature of the transition is experimentally assessed using phase diagrams, hysteresis phenomena, magnetic susceptibility, and magnetization fluctuations. The observed features are found to be consistent with mean-field calculations, and experimental protocols are developed to generate domain walls in the ferromagnetic state.
Proceedings Paper
Engineering, Electrical & Electronic
Alice Meda, Cecilia Clivati, Salvatore Virzi, Simone Donadello, Alberto Mura, Filippo Levi, Marco Genovese, Ivo Degiovanni, Davide Calonico
Summary: The integration of QKD protocols in metropolitan networks requires addressing the challenges posed by unstable optical channels and background photons. Researchers have proposed an interferometry-based solution for precise channel length control and demonstrated its effectiveness.
2022 IEEE 15TH WORKSHOP ON LOW TEMPERATURE ELECTRONICS (WOLTE 2022)
(2022)
Article
Optics
Louise Wolswijk, Carmelo Mordini, Arturo Farolfi, Dimitris Trypogeorgos, Franco Dalfovo, Alessandro Zenesini, Gabriele Ferrari, Giacomo Lamporesi
Summary: This study investigates the strong out-of-equilibrium dynamics occurring when a harmonically trapped ultracold bosonic gas is evaporatively cooled across the Bose-Einstein condensation transition. The results show that the cooling rate affects the timescales for the growth of the condensate order parameter and the relaxation dynamics of its spatial fluctuations.
Article
Optics
A. Farolfi, A. Zenesini, R. Cominotti, D. Trypogeorgos, A. Recati, G. Lamporesi, G. Ferrari
Summary: In this study, we experimentally characterized a spatially extended Josephson junction using a coherently coupled two-spin-component Bose-Einstein condensate. The trapped cloud allowed for the freezing of transverse spin excitations. Our results suggest consistency with a simple local density approximation of spin hydrodynamics, the so-called Bose-Josephson junction equations, across different manipulation protocols. Additionally, we identified a method to generate states with a well-defined uniform magnetization.
