Article
Multidisciplinary Sciences
Dieter Schuch, Moise Bonilla-Licea
Summary: Shortly after Schrödinger's wave mechanics, Madelung formulated it in terms of real hydrodynamic-like equations. This formulation is the basis of Bohmian mechanics with a different interpretation. The criticism against Bohmian mechanics is its lack of symmetry between position and momentum, which is present in classical phase space and quantum mechanical representations. Madelung's formulation and Bohmian mechanics are usually expressed in position space only. Recently, we extended this formalism to include dissipative systems with broken time-reversal symmetry.
Article
Physics, Fluids & Plasmas
Yan V. Fyodorov, Elizaveta Safonova
Summary: Using the method of random matrix theory with supersymmetry within the framework of the Heidelberg approach, this study provides a statistical description of stationary intensity inside an open wave-chaotic cavity. It is shown that the probability density of single-point intensity decays as a power law for large intensities when incoming waves are fed via a finite number of open channels, with a marked difference from the Rayleigh law. The joint probability density of intensities in multiple observation points and the statistics for the maximal intensity in the observation pattern are also analyzed.
Article
Physics, Fluids & Plasmas
Niklas Grimm, Annette Zippelius, Matthias Fuchs
Summary: This article characterizes the effect of collision rules on velocity correlations in a system of hard spheres. The results show that there are long-range correlations between velocities in a nonequilibrium state, which is consistent with previous research findings.
Article
Physics, Multidisciplinary
Xiaoliang Xiao, Fangyang Zhan, Weixiang Kong, Jing Fan, Rui Wang, Xiaozhi Wu
Summary: In this study, a van der Waals heterostructure ZrTe5/Cr2Ge2Te6 is found to realize a robust time-reversal symmetry-breaking quantum spin Hall state through first-principles calculations and topology analysis. The presence of the time-reversal symmetry-breaking quantum spin Hall phase is confirmed by utilizing topological edge states and spin Hall conductance, which can be directly measured in experiments. The authors also discover that the built-in electric field is essential for realizing such a topological state, and an external electric field can effectively tune the nontrivial band gap.
NEW JOURNAL OF PHYSICS
(2022)
Article
Physics, Multidisciplinary
Koshi Okamura
Summary: This paragraph summarizes the revised time-reversal symmetry in a nonmagnetic condensed-matter system, indicating its dependence on the spatial symmetry of two-fold rotation in addition to the conventional inversion. Representative systems like Si and GaAs are used to demonstrate the Bloch state under the constraints of spatial and time-reversal symmetries based on first-principles calculations. Additionally, the nondegenerate gapless state in a topological system is also assessed.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2023)
Article
Physics, Multidisciplinary
Hamidreza Emamipour
Summary: This study investigates the tunneling conductance in graphene-based ferromagnet-normal metal-superconductor junction with time-reversal symmetry broken. It is found that exchange field of ferromagnet suppresses the tunneling conductance for various pairing states, but increases when Fermi wave mismatch is present. Adjusting bias voltages and junction parameters can help differentiate between different symmetry states.
Article
Materials Science, Multidisciplinary
Duo Zhao, Jiaqian Sun, Wei Tang, Yu-Jia Zeng
Summary: The Ising magnetoresistance induced by Ising spin-orbit coupling has significant importance in explaining unconventional observations and physical phenomena in low-symmetry two-dimensional materials.
Article
History & Philosophy Of Science
Cristian Lopez, Michael Esfeld
Summary: In this paper, we propose an alternative interpretation of time-reversal symmetry in philosophy of physics: Humean time-reversal symmetry. According to this interpretation, time-reversal symmetry is understood as a heuristic, epistemic virtue of the best system, rather than a property of the Humean mosaic. One consequence of this view is that one of the main arguments against a primitive direction of time is rendered harmless, paving the way for primitivism about the direction of time.
Article
Materials Science, Multidisciplinary
Joseph Poata, Fabio Taddei, Michele Governale
Summary: In this paper, the occurrence and features of corner states in convex polygon flakes are theoretically studied. The presence of corner states between two given edges is determined by analyzing the sign of their induced masses, and general rules for convex polygon flakes are derived. Numerical simulations are conducted to validate the theoretical findings.
Article
Materials Science, Multidisciplinary
Haotian Wu, Xinxin Gao, Shuo Liu, Qian Ma, Hao Chi Zhang, Xiang Wan, Tie Jun Cui
Summary: A new mechanism for controlling electromagnetic wave flow based on spatiotemporal metasurface assisted with parity-time (PT) symmetric modulations is proposed and experimentally verified in the microwave regime. The generated spin-momentum coupling can be flexibly switched in real time, providing a powerful platform for exploring physical effects that are hard to realize in traditional photonic topological systems.
ADVANCED OPTICAL MATERIALS
(2021)
Article
Engineering, Multidisciplinary
Kadry Zakaria, Abdullah M. Alsharif
Summary: The linear instability of a planar jet surrounded by an inviscid gas medium is investigated with the presence of odd viscosity for various modes. Previous studies did not consider the role of odd viscosity in measuring growth rate, wave number, instability limit, and breakup length. Odd viscosity is a stabilizing factor for liquid sheets but can be unstable in certain cases due to model parameters. Sprays are widely used in the production of metal alloys, metal powders, and downstream metal manufacturing processes, particularly in the steel industry.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Physics, Multidisciplinary
Yotam Shapira, Tom Manovitz, Nitzan Akerman, Ady Stern, Roee Ozeri
Summary: Research on many-body systems of quantum interacting particles with broken time-reversal symmetry is important for understanding a variety of collective behaviors. Quantum simulators are potential tools for exploring and understanding such systems. However, achieving programmable interactions, strong time-reversal symmetry breaking, and high-fidelity quantum control in a scalable manner is challenging.
Article
Multidisciplinary Sciences
Kohei Matsuura, Masaki Roppongi, Mingwei Qiu, Qi Sheng, Yipeng Cai, Kohtaro Yamakawa, Zurab Guguchia, Ryan P. Day, Kenji M. Kojima, Andrea Damascelli, Yuichi Sugimura, Mikihiko Saito, Takaaki Takenaka, Kota Ishihara, Yuta Mizukami, Kenichiro Hashimoto, Yilun Gu, Shengli Guo, Licheng Fu, Zheneng Zhang, Fanlong Ning, Guoqiang Zhao, Guangyang Dai, Changqing Jin, James W. Beare, Graeme M. Luke, Yasutomo J. Uemura, Takasada Shibauchi
Summary: Iron-chalcogenide superconductors FeSe1-xSx have unique electronic properties and the nature of superconductivity with nematicity is important for understanding unconventional superconductivity. Recent experiments show that the superconducting state in FeSe1-xSx breaks time-reversal symmetry and exhibits ultranodal pair state. The presence of broken TRS and suppressed superfluid density suggests the existence of two different superconducting states separated by the nematic critical point.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Materials Science, Multidisciplinary
Andrew C. Yuan, Erez Berg, Steven A. Kivelson
Summary: The study demonstrates that the superconducting state in Sr2RuO4 can degenerate at an assumed tetracritical point. Spatially varying strain can lead to different states of the superconducting state, including those preserving time-reversal symmetry and those breaking it at region boundaries. This research shows that various natural patterns of strain induce a rich variety of superconducting textures, possibly resolving inconsistencies between theoretical proposals and experimental observations.
Article
Physics, Multidisciplinary
Tian-Shu Deng, Lei Pan, Yu Chen, Hui Zhai
Summary: This study investigates the stability of Kramers degeneracy and nontrivial topological states under time-reversal symmetry against coupling to the environment. The results show that dissipation can lead to splitting of spectral functions for degenerate states and induce backscattering between counterpropagating edge states, causing the absence of accurate quantization of conductance in the case of the quantum spin Hall effect. The findings have implications for interacting topological phases protected by time-reversal symmetry.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Nikita Nefedkin, Ahmed Mekawy, Jonas Krakofsky, Yongrui Wang, Alexey Belyanin, Mikhail Belkin, Andrea Alu
Summary: Engineered intersubband transitions in multi-quantum well semiconductor heterostructures exhibit high second-order nonlinear susceptibilities in metasurfaces. By optimizing the design, the saturation limits in mid-infrared frequency upconversion in nonlinear metasurfaces are significantly extended. This has important implications for night-vision imaging and compact nonlinear wave mixing systems.
ADVANCED MATERIALS
(2023)
Article
Physics, Multidisciplinary
Guoqiang Xu, Yihao Yang, Xue Zhou, Hongsheng Chen, Andrea Alu, Cheng-Wei Qiu
Summary: This study discovers diffusion-based topological states supported by spatiotemporally modulated advections on a fluidic surface. It establishes a framework for topological diffusion and thermal edge or bulk states, potentially enabling flexible manipulation of heat and mass transfer.
Review
Physics, Multidisciplinary
Lujun Huang, Alex Krasnok, Andrea Alu, Yiling Yu, Dragomir Neshev, Andrey E. Miroshnichenko
Summary: Two-dimensional transition metal dichalcogenide materials have extraordinary electronic, optical, and thermal properties, with monolayers exhibiting strong photoluminescence due to high quantum yields. Resonant nanophotonic structures enhance light-matter interactions and performance. Rapidly developing field with diverse potential applications.
REPORTS ON PROGRESS IN PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Y. Ra'di, A. Alu
Summary: In this paper, the authors review the physical mechanisms, functionalities, and recent progress of metagratings. Conventional gradient metasurfaces have limitations in rerouting impinging waves with overall efficiency, especially for extreme wavefront transformations. However, metagratings can manipulate light with unitary efficiency even in extreme conditions and offer advantages such as simpler fabrication and broader bandwidths.
IEEE PHOTONICS JOURNAL
(2022)
Article
Optics
Matt Markowitz, Michele Cotrufo, You Zhou, Karl Stensvad, Craig Schardt, Adam Overvig, Andrea Alu
Summary: Tailored resonant waveguide gratings (RWG) embedded in a glass-like matrix are explored as angularly tolerant tri-band reflection filters under oblique excitation. Through inverse design, 1D grating structures are optimized to support multi-frequency narrow-band resonances in an otherwise transparent background, ideally suited for augmented reality applications.
Article
Physics, Multidisciplinary
Huanan Li, Shixiong Yin, Andrea Alu
Summary: This study demonstrates nonreciprocity for temporal boundaries by showing Faraday polarization rotation in a magnetoplasma with abruptly switched material properties. The findings open new opportunities for time metamaterials and wave engineering.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Junghyun Shin, Younghun Ryu, Mohammad-Ali Miri, Seung-Bo Shim, Hyoungsoon Choi, Andrea Alu, Junho Suh, Jinwoong Cha
Summary: This study explores the generation of microwave frequency combs using a niobium-based superconducting electromechanical device, and observes the formation of combs with a frequency spacing of 8 MHz around a microwave resonant frequency. The experimental results show excellent agreement with numerical modeling, highlighting the important application value of these electromechanical frequency combs in nanomechanical sensing.
Article
Multidisciplinary Sciences
Neda Alsadat Aghamiri, Guangwei Hu, Alireza Fali, Zhen Zhang, Jiahan Li, Sivacarendran Balendhran, Sumeet Walia, Sharath Sriram, James H. Edgar, Shriram Ramanathan, Andrea Alu, Yohannes Abate
Summary: This study introduces a hybrid polaritonic-oxide heterostructure platform for nanoscale active control of polaritons. By utilizing scanning probe microscopy and infrared nanoimaging techniques, the authors demonstrate the nanoscale reconfigurability of complex phonon polaritons with high resolution. The use of correlated perovskite oxide substrates allows for real-time modulation and nanoscale reconfiguration of hyperbolic polaritons in van der Waals crystals.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Julian Klein, Zhigang Song, Benjamin Pingault, Florian Dirnberger, Hang Chi, Jonathan B. Curtis, Rami Dana, Rezlind Bushati, Jiamin Quan, Lukas Dekanovsky, Zdenek Sofer, Andrea Alu, Vinod M. Menon, Jagadeesh S. Moodera, Marko Loncar, Prineha Narang, Frances M. Ross
Summary: Atomic-level defects in van der Waals (vdW) materials are essential for quantum technologies and sensing applications. The magnetic semiconductor CrSBr, with a direct gap and rich magnetic phase diagram, exhibits optically active defects that are correlated with the magnetic environment. The narrow defect emission in CrSBr is related to both the bulk magnetic order and an additional defect-induced magnetic order. This study establishes vdW magnets like CrSBr as an exceptional platform for studying defects and creating tailor-made magnetic textures with optical access.
Article
Nanoscience & Nanotechnology
Guangwei Hu, Weiliang Ma, Debo Hu, Jing Wu, Chunqi Zheng, Kaipeng Liu, Xudong Zhang, Xiang Ni, Jianing Chen, Xinliang Zhang, Qing Dai, Joshua D. Caldwell, Alexander Paarmann, Andrea Alu, Peining Li, Cheng-Wei Qiu
Summary: Various optical crystals with opposite permittivity components have been observed and characterized in the mid-infrared regime. These crystals possess hyperbolic polaritons with large-momenta optical modes and wave confinement, making them promising for nanophotonic on-chip technologies. Monoclinic CdWO4 crystals are shown to exhibit symmetry-broken hyperbolic phonon polaritons and offer new opportunities for polaritonic phenomena.
NATURE NANOTECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Andrea Cordaro, Brian Edwards, Vahid Nikkhah, Andrea Alu, Nader Engheta, Albert Polman
Summary: As traditional microelectronic technology reaches its limits in speed and power consumption, there is a strong demand for novel computing strategies. Analogue optical computing has the advantage of processing large amounts of data at high speeds with negligible energy costs. Researchers have recently explored ultrathin optical metasurfaces for real-time image processing, particularly for edge detection. By incorporating feedback, they have also demonstrated that metamaterials can be used to solve complex mathematical problems, although this has been limited to guided-wave systems and large setups. This study presents an ultrathin Si metasurface-based platform for analogue computing, capable of solving Fredholm integral equations of the second kind using free-space visible radiation. The device combines an inverse-designed Si-based metagrating with a semitransparent mirror to perform the required Neumann series and solve the equation in the analogue domain at the speed of light. The use of visible wavelength operation enables a compact, ultrathin device that can be integrated on a chip and has high processing speeds.
NATURE NANOTECHNOLOGY
(2023)
Editorial Material
Materials Science, Multidisciplinary
Andrea Alu
Summary: Optical Materials Express Editor-in-Chief, Andrea Ali, has introduced new topic categories for the Journal, redefining the Journal scope and better reflecting the current state of this dynamic field of research.
OPTICAL MATERIALS EXPRESS
(2023)
Article
Nanoscience & Nanotechnology
Sander A. . Mann, Heedong Goh, Andrea Alu
Summary: Enabling strong nonlinear optical phenomena requires carefully designed photonic devices to maximize light-matter interactions. Topology optimization has been widely used in optimizing photonic devices due to its efficiency in dealing with large parameter spaces. However, the application of topology optimization in nonlinear effects in dielectric structures is limited.
Article
Nanoscience & Nanotechnology
Nikita Nefedkin, Michele Cotrufo, Andrea Alu
Summary: Nonreciprocity originating from classical interactions among nonlinear scatterers is explored in this work, offering a promising tool for quantum information processing and quantum computing. It is shown that large nonreciprocal responses can be achieved in nonlinear systems by controlling the position and transition frequencies of the atoms, without requiring a nonreciprocal environment. The connection between this effect and the asymmetric population of a slowly decaying dark state is demonstrated.
Article
Physics, Applied
Romain Tirole, Emanuele Galiffi, Jakub Dranczewski, Taran Attavar, Benjamin Tilmann, Yao-Ting Wang, Paloma A. Huidobro, Andrea Alu, John B. Pendry, Stefan A. Maier, Stefano Vezzoli, Riccardo Sapienza
Summary: We report a switchable time-varying mirror composed of an indium-tin-oxide-gold bilayer that exhibits a tenfold modulation of reflectivity. The reflected pulse's frequency content is extended beyond the pump spectral content by interacting with the saturated mirror. The shortening of the mirror's rise time with increasing pump power enables applications in spectral manipulation, communication networks, optical switching, and computing.
PHYSICAL REVIEW APPLIED
(2022)