Article
Engineering, Electrical & Electronic
Deyun Wei, Jun Yang
Summary: The discrete fractional Fourier transform is a useful tool in non-stationary signal processing. This paper proposes a two-dimensional sparse fractional Fourier transform (2D SFRFT) algorithm, which achieves the lowest runtime and sample complexity compared to existing methods. The algorithm is improved to be robust by analyzing errors due to noises, and its effectiveness is demonstrated in various applications.
Article
Chemistry, Physical
Buyang Yu, Lan Chen, Zhengkang Qu, Chunfeng Zhang, Zhengyuan Qin, Xiaoyong Wang, Min Xiao
Summary: The study demonstrates the presence of a phonon bottleneck effect in CsPbI3 nanocrystals through broadband two-dimensional electronic spectroscopy, showing a size-dependent relaxation of hot carriers and doubling of their lifetime as the nanocrystal size decreases. This finding suggests the feasibility of controlling hot carrier dynamics in perovskite semiconductors for potential applications.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Biochemistry & Molecular Biology
Amber R. Titus, Pedro P. Madeira, Luisa A. Ferreira, Vladimir Y. Chernyak, Vladimir N. Uversky, Boris Y. Zaslavsky
Summary: This work presents experimental evidence that mesoscopic changes occur before macroscopic phase separation in aqueous mixtures. Through dynamic light scattering and spectroscopic analysis, quantitative estimates of these changes are obtained and a model of phase separation is developed.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Applied
Huanjiong An, Qianyun Ma, Fan Zhang, Chen Zhai, Jianfeng Sun, Yiwei Tang, Wenxiu Wang
Summary: This study analyzed the starch retrogradation process by using 2D-COS analysis on FTIR and Raman spectroscopy data. It identified quantitative peaks related to starch retrogradation and established a quantitative partial least squares model to determine the degree of starch retrogradation. The findings have implications for improving the quality of starch-based food products.
FOOD HYDROCOLLOIDS
(2024)
Article
Optics
Jieli Yan, Stephen Revesz, Danfu Liang, Hebin Li
Summary: Optical two-dimensional coherent spectroscopy (2DCS) is a useful tool for studying energy level structure and dynamics in atomic ensembles. In this study, a broadband optical 2DCS experiment was conducted on rubidium atoms, which have different D line characteristics compared to potassium atoms. The experimental results were consistent with simulated spectra based on the perturbation solutions. This work allows for the study of many-body interactions and correlations in rubidium atoms using double-quantum and multiquantum 2DCS.
Article
Optics
Yirong Xu, Shangyuan Li, Zhengyuan Zhu, Xiaoxiao Xue, Xiaoping Zheng, Bingkun Zhou
Summary: In this study, a photonic-assisted space-frequency two-dimensional (2D) compressive radar receiver is proposed to achieve high-resolution detection in wide-range scenarios. The system employs spatially adaptive photonic projection basis for compression in the space dimension and photonic compressive sensing for compression in the frequency dimension. The proposed receiver overcomes the resolution deterioration problem of existing photonic compressive receivers and enables wide-range radar detection and inverse synthetic aperture radar (ISAR) imaging with high resolution.
Article
Mathematics, Applied
Waseem Z. Lone, Firdous A. Shah, Ahmed Zayed
Summary: The aim of this study is to introduce a convolution-based two-dimensional fractional shearlet transform in the context of fractional time-frequency analysis. The preliminary analysis encompasses the derivation of fundamental properties of the novel integral transform including the orthogonality relation, inversion formula, and the range theorem. To extend the scope of the study, the cone adapted variant of the two-dimensional fractional shearlet transform is also studied in detail. Nevertheless, several coherent examples are presented to facilitate a sound illustration of the concepts.
FRACTIONAL CALCULUS AND APPLIED ANALYSIS
(2022)
Article
Optics
Xinyu Chen, Hao Ming, Chenjia Li, Guangqiang He, Fan Zhang
Summary: An ANN-based scheme is proposed to enhance the performance of NFDM optical transmission systems; Two-stage ANN equalization is used to jointly mitigate time and frequency domain distortions; Numerical simulations show significant Q-factor gain in multi-dimensional signal equalization.
Article
Engineering, Electrical & Electronic
Ahmed Zayed
Summary: This paper discusses the fractional Fourier transform, including its applications and the derivation of a sampling theorem for a new two-dimensional transform. Unlike the traditional tensor product case, the new sampling theorem involves Sinc functions dependent on weighted sums and differences of transform variables, resulting in more diverse configuration and distribution of sample points.
Article
Chemistry, Physical
Hans-Peter Solowan, Pavel Maly, Tobias Brixner
Summary: This study uses 2DES technique to measure the excitation pathways of azulene from S-0 to S-2 state in both liquid and gas phase, and assesses the effect of solvent and the interplay of intra- and intermolecular energy relaxation through a comparison between the two phases.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Ramanathan Kamalakkannan, Rajakumar Roopkumar
Summary: In this paper, a new two-dimensional fractional Stockwell transform is introduced using the kernel of the coupled fractional Fourier transform. It is shown that this transform satisfies expected properties, including Parseval identity and inversion formula, and its range on L-2(R-2) is characterized alongside a convolution theorem. Uncertainty principles for the coupled fractional Fourier transform and the two-dimensional fractional Stockwell transform are also proven.
CIRCUITS SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Automation & Control Systems
Yuxin Lin, Bingo Wing-Kuen Ling, Nuo Xu, Xueling Zhou
Summary: This paper presents a color image denoising method based on two-dimensional quaternion valued singular spectrum analysis (2DQSSA), which can simultaneously exploit the relationship among color planes and the local information within each color plane. Compared to traditional methods and non-overlapping methods, the 2DQSSA based denoising method achieves better denoising results.
JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS
(2022)
Article
Optics
Yunyou Hu, Liang Xu, Hanyang Xu, Xianchun Shen, Yasong Deng, Huanyao Xu, Jianguo Liu, Wenqing Liu
Summary: This paper presents a method for gas leak monitoring using remote sensing imaging technology, which utilizes scanning FTIR remote-sensing imaging systems to achieve 3-D quantitative reconstruction of gas clouds, thereby obtaining detailed information and locating the source of gas leaks accurately.
Review
Chemistry, Multidisciplinary
Somnath Biswas, JunWoo Kim, Xinzi Zhang, Gregory D. Scholes
Summary: Coherent broadband spectroscopy and two-dimensional electronic spectroscopy have been widely used to investigate ultrafast processes and have made significant progress. These techniques provide important theoretical frameworks and experimental methods for optimizing the photophysical properties of various artificial systems.
Article
Optics
Mengqi Han, Wengjing Chen
Summary: In this study, a two-dimensional complex wavelet with an asymmetric frequency envelope and direction selectivity is proposed for single-frame fringe projection profilometry. The experimental results demonstrate high phase accuracy, validating the effectiveness of the method.
Article
Multidisciplinary Sciences
Fabio Novelli, Jonathan O. Tollerud, Dharmalingam Prabhakaran, Jeffrey A. Davis
Article
Optics
Eugeniu Balaur, Guido A. Cadenazzi, Nicholas Anthony, Alex Spurling, Eric Hanssen, Jacqueline Orian, Keith A. Nugent, Belinda S. Parker, Brian Abbey
Summary: The invention of phase contrast microscopy has enabled the visualization of highly optically transparent samples without the need for staining, revolutionizing optics. Advanced approaches to phase imaging, such as the combination of ptychographic coherent diffractive imaging with plasmonically active metamaterials, have shown significant enhancement in both reconstructed phase and amplitude. This approach opens up new possibilities for imaging a wide range of extremely thin or highly transparent objects previously inaccessible to optical microscopy.
Article
Physics, Multidisciplinary
Jia Wang, Peter Hannaford, Bryan J. Dalton
Summary: A fully comprehensive multi-mode quantum treatment based on truncated Wigner approximation (TWA) was used to study many-body effects and quantum fluctuations on the formation of a discrete time crystal (DTC) in a Bose-Einstein condensate (BEC) bouncing on a periodically driven atom mirror. The study showed that TWA approach can provide accurate predictions and observed the possibility of creating a stable DTC based on repulsive interactions. Additionally, the dynamical behavior of the system was found to be largely independent of whether the boson-boson interaction is attractive or repulsive, indicating the robustness of the system.
NEW JOURNAL OF PHYSICS
(2021)
Article
Multidisciplinary Sciences
M. Wurdack, E. Estrecho, S. Todd, T. Yun, M. Pieczarka, S. K. Earl, J. A. Davis, C. Schneider, A. G. Truscott, E. A. Ostrovskaya
Summary: Room-temperature exciton polaritons in a monolayer WS2 exhibit narrow linewidth and enhanced coherence, capable of propagating over tens of micrometers with partial coherence and displaying ballistic transport characteristics. When interacting with cavity photons in optical microcavities, excitons in TMDCs can form exciton polaritons with inherited useful properties.
NATURE COMMUNICATIONS
(2021)
Article
Biochemical Research Methods
Alireza Lajevardipour, Zoltan Vilagosh, Dominique Appadoo, Jeffrey Davis, Saulius Juodkazis, Andrew Wood
Summary: The study found that products containing moisturizing ingredients such as glycerol and sorbitol have significant absorption characteristics in the far-infrared range, while sunscreen ingredients have relatively low absorbance rates. Components like melanin and collagen in dehydrated skin samples also show significant absorption properties, but not as important as moisturizing agents.
BIOMEDICAL OPTICS EXPRESS
(2021)
Article
Multidisciplinary Sciences
Eugeniu Balaur, Sandra O' Toole, Alex J. Spurling, G. Bruce Mann, Belinda Yeo, Kate Harvey, Catherine Sadatnajafi, Eric Hanssen, Jacqueline Orian, Keith A. Nugent, Belinda S. Parker, Brian Abbey
Summary: This study demonstrates the generation of colorimetric histology images using full-sized plasmonically active microscope slides. These slides translate subtle changes in dielectric constant into striking color contrast when samples are placed on them. The biomedical potential of this technique is shown by distinguishing neoplastic cells from normal breast epithelium in mouse models and in human diagnostic tissue. Comparing the colorimetric output with conventional histopathology shows the potential for histoplasmonics as an alternative or adjunct to staining.
Article
Materials Science, Multidisciplinary
M. A. Conway, J. B. Muir, S. K. Earl, M. Wurdack, R. Mishra, J. O. Tollerud, J. A. Davis
Summary: This study successfully identifies and separates the optically excited biexciton in monolayer WS2 using two-quantum multidimensional coherent spectroscopy (2Q-MDCS), and measures the binding energy of the biexciton. The biexciton is composed of two bright excitons in opposite valleys.
Correction
Multidisciplinary Sciences
M. Wurdack, E. Estrecho, S. Todd, T. Yun, M. Pieczarka, S. K. Earl, J. A. Davis, C. Schneider, A. G. Truscott, E. A. Ostrovskaya
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Susannah Holmes, Henry J. Kirkwood, Richard Bean, Klaus Giewekemeyer, Andrew Martin, Marjan Hadian-Jazi, Max O. Wiedorn, Dominik Oberthuer, Hugh Marman, Luigi Adriano, Nasser Al-Qudami, Sasa Bajt, Imrich Barak, Sadia Bari, Johan Bielecki, Sandor Brockhauser, Mathew A. Coleman, Francisco Cruz-Mazo, Cyril Danilevski, Katerina Doerner, Alfonso M. Ganan-Calvo, Rita Graceffa, Hans Fanghor, Michael Heymann, Matthias Frank, Alexander Kaukher, Yoonhee Kim, Bostjan Kobe, Juraj Knoska, Torsten Laurus, Romain Letrun, Luis Maia, Marc Messerschmidt, Markus Metz, Thomas Michelat, Grant Mills, Serguei Molodtsov, Diana C. F. Monteiro, Andrew J. Morgan, Astrid Muennich, Gisel E. Pena Murillo, Gianpietro Previtali, Adam Round, Tokushi Sato, Robin Schubert, Joachim Schulz, Megan Shelby, Carolin Seuring, Jonas A. Sellberg, Marcin Sikorski, Alessandro Silenzi, Stephan Stern, Jola Sztuk-Dambietz, Janusz Szuba, Martin Trebbin, Patrick Vagovic, Thomas Ve, Britta Weinhausen, Krzysztof Wrona, Paul Lourdu Xavier, Chen Xu, Oleksandr Yefanov, Keith A. Nugent, Henry N. Chapman, Adrian P. Mancuso, Anton Barty, Brian Abbey, Connie Darmanin
Summary: The European XFEL MHz SFX technique enables tracking of sub-microsecond structural changes in individual crystals, allowing for multi-hit serial crystallography. This technique overcomes the issue of radiation damage in traditional methods.
NATURE COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
L. Chu Van, B. T. Le Tran, T. Nguyen Thi, D. Hoang Trong, T. Dang Van, T. Do Mai, H. Trinh Ngoc, T. Thai Doan, K. Doan Quoc
Summary: This article investigates the nonlinear characteristics of three newly designed benzene-core photonic crystal fibers and selects the optimal fiber structure. The results demonstrate that these fibers are highly efficient for supercontinuum generation.
OPTICAL AND QUANTUM ELECTRONICS
(2022)
Article
Multidisciplinary Sciences
Jack B. Muir, Jesper Levinsen, Stuart K. Earl, Mitchell A. Conway, Jared H. Cole, Matthias Wurdack, Rishabh Mishra, David J. Ing, Eliezer Estrecho, Yuerui Lu, Dmitry K. Efimkin, Jonathan O. Tollerud, Elena A. Ostrovskaya, Meera M. Parish, Jeffrey A. Davis
Summary: Researchers introduced mobile exciton impurities into a two-dimensional electron gas and conducted experiments on monolayer WS2 using multi-dimensional coherent spectroscopy. They found that at low electron doping densities, the dominant interactions occur between polaron states dressed by the same Fermi sea. Additionally, they discovered a bipolaron bound state with remarkably large binding energy involving excitons in different valleys cooperatively bound to the same electron.
NATURE COMMUNICATIONS
(2022)
Article
Optics
Lanh Chu Van, Ngoc Vo Thi Minh, Bao Tran Le Tran, Trong Dang Van, Phuong Nguyen Thi Hong, Trang Do Mai, Trung Le Canh, Hieu Van Le, Thuy Nguyen Thi, Thanh Thai Doan, Van Thuy Hoang
Summary: This article investigates the use of tapered liquid-core fibers for supercontinuum generation through numerical simulations. The results show that tapered fibers have the potential for high coupling efficiency and high nonlinearity. By changing the core diameter, both all-normal dispersion and anomalous dispersion supercontinuum generation can be achieved. Furthermore, the use of cascaded tapered fibers can mitigate thermal effects and increase the stability of the output supercontinuum spectra.
OPTICS COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Mitchell A. Conway, Stuart K. Earl, Jack B. Muir, Thi-Hai-Yen Vu, Jonathan O. Tollerud, Kenji Watanabe, Takashi Taniguchi, Michael S. Fuhrer, Mark T. Edmonds, Jeffrey A. Davis
Summary: By using multidimensional coherent spectroscopy, we excited, controlled, and probed a coherent superposition of excitons in the K and K' valleys in monolayer WS(2). We observed phase rotations greater than π and showed that this could be described by a combination of the AC-Stark shift and the Bloch-Siegert shift. However, the process was not perfectly adiabatic and additional decoherence caused by power broadening was observed. These nonadiabatic effects may pose problems for certain applications, but the measurements also suggest ways to minimize or eliminate them.
Article
Materials Science, Multidisciplinary
S. K. Earl, M. A. Conway, J. B. Muir, M. Wurdack, E. A. Ostrovskaya, J. O. Tollerud, J. A. Davis
Summary: The research team used femtosecond laser pulses to demonstrate the optical Stark effect in monolayer WS2, showing adiabatic evolution of the system and linear dependence of induced energy shift on instantaneous intensity, even for ultrafast driving fields of fewer than 15 optical cycles.
Article
Computer Science, Artificial Intelligence
Pavel Kolesnichenko, Qianhui Zhang, Changxi Zheng, Michael S. Fuhrer, Jeffrey A. Davis
Summary: Despite the great promise of 2D materials for various applications, the reality of device proliferation and meeting real-life demands is still far from being achieved. Experimentally obtainable samples commonly experience a wide range of perturbations that significantly deviate the properties from idealistic models, making it challenging for physical property interpretations and disentanglement of effects. Through statistical correlation analysis and unsupervised machine learning algorithms, we can identify dominant components related to tensile strain, disorder induced by environmental molecules, multi-layer regions, and charge doping, in excitonic spectra of WS2 monolayers. This approach has the potential to determine the local environment of 2D materials and pave the way for advanced, machine-aided characterization of monolayer matter.
MACHINE LEARNING-SCIENCE AND TECHNOLOGY
(2021)
