Article
Physics, Multidisciplinary
Tao Gong, Inigo Liberal, Benjamin Spreng, Miguel Camacho, Nader Engheta, Jeremy N. Munday
Summary: The Casimir effect is a phenomenon where macroscopic metallic objects experience an attractive force due to vacuum fluctuation-induced interactions. This force is influenced by both plasmonic and photonic modes. In this study, we investigate the Casimir interaction between ultrathin films and find pronounced repulsive contributions to the force caused by highly confined and nearly dispersion-free epsilon-near-zero (ENZ) modes unique to ultrathin films. These contributions occur consistently around the ENZ frequency of the film regardless of interfilm separation. We also observe a thickness dependence of a figure of merit (FOM) for conductive thin films associated with ENZ modes, suggesting enhanced motion of objects induced by Casimir interactions for deeply nanoscale sizes.
PHYSICAL REVIEW LETTERS
(2023)
Article
Mathematics, Applied
F. Tajik, N. Allameh, A. A. Masoudi, G. Palasantzas
Summary: The study investigates the dynamical actuation of MEMS under the influence of Casimir forces between topological insulator plates, analyzing the impact of dielectric function and coating magnetization on the attractive and repulsive forces. The results show that the forces vary with the dielectric function and magnetization, affecting the stability and chaotic motion of the systems.
Article
Physics, Particles & Fields
Remo Garattini
Summary: This work explores a Yukawa modification of the Casimir wormhole, applying a Zero Tidal Forces Equation of State. Two different approaches are examined, one fixing the shape function in various ways and the other deducing the form of the shape function from the original Casimir source modified by a Yukawa term. The connection with the Absurdly Benign Traversable Wormhole is also discussed.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Nanoscience & Nanotechnology
Zhujing Xu, Xingyu Gao, Jaehoon Bang, Zubin Jacob, Tongcang Li
Summary: The study explores the non-reciprocal energy transfer phenomenon caused by quantum vacuum fluctuations, demonstrating strong coupling between two micromechanical oscillators through modulation of Casimir interaction parameters, leading to non-reciprocal energy transfer.
NATURE NANOTECHNOLOGY
(2022)
Article
Multidisciplinary Sciences
Zhujing Xu, Peng Ju, Xingyu Gao, Kunhong Shen, Zubin Jacob, Tongcang Li
Summary: This study reports an experimental demonstration of Casimir force exerted among three objects, using a unique sphere-plate-sphere geometry. The research also proposes and demonstrates a three-terminal switchable architecture for opto-mechanical Casimir interactions which could lead to the development of a Casimir transistor with potential applications in sensing and information processing.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
Tanja Schoger, Benjamin Spreng, Gert-Ludwig Ingold, Paulo A. Maia Neto, Serge Reynaud
Summary: We studied the Casimir interaction between two dielectric spheres immersed in a salted solution and found that this interaction exhibits universality properties at distances larger than the Debye screening length. This finding is important for the modeling of colloids and biological interfaces.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Thorsten Emig, Giuseppe Bimonte
Summary: Recent measurements of Casimir forces have shown that quantum fluctuations of the electromagnetic field undergo intricate modifications in complex geometries. In this paper, a multiple scattering description is introduced for calculating Casimir interactions between bodies of arbitrary shape and material composition. This approach allows for the calculation of interactions in complex geometries using just a few wave scatterings, without any prior knowledge of the scattering amplitudes of the bodies. Some initial applications demonstrate the efficacy of this method.
PHYSICAL REVIEW LETTERS
(2023)
Article
Multidisciplinary Sciences
Battulga Munkhbat, Adriana Canales, Betul Kucukoz, Denis G. Baranov, Timur O. Shegai
Summary: This study introduces a method for stable microcavity formation based on self-assembly of gold nanoflake pairs in an aqueous solution, utilizing the equilibrium between attractive Casimir forces and repulsive electrostatic forces. The system allows for tunable optical microcavities with adjustable equilibrium configurations, enabling the realization of hybrid light-matter states. These Casimir microcavities could potentially be used in opto-mechanics, nanomachinery, and cavity-induced polaritonic chemistry.
Article
Chemistry, Physical
H. J. Jonas, S. G. Stuij, P. Schall, P. G. Bolhuis
Summary: Researchers have developed a protocol based on a combination of theoretical Casimir potentials and angular switching functions to establish a model for synthetic colloidal patchy particles. By optimizing model parameters through Monte Carlo simulations, they were able to match experimental observations. This approach provides a systematic way to accurately model critical Casimir induced patchy particle interactions for large-scale simulations.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Optics
John Joseph Marchetta, Prachi Parashar, K. Shajesh
Summary: This study explores the repulsion effects on an anisotropically polarizable atom located on the symmetry axis of an anisotropically polarizable annular disk, which has two torsion-free points on each side. The position of the second torsion-free point on either side affects the orientation dependence of the atom, showing a geometrical relationship. In the ring limit of the annular disk, an additional region of repulsion is observed.
Article
Physics, Multidisciplinary
C. Romaniega
Summary: This study focuses on the electromagnetic Casimir-Lifshitz interaction between two bodies, specifically examining the fluctuation-induced pressure on the cavity wall. The research reveals that the sign of the pressure is independent of the geometry of the configuration.
EUROPEAN PHYSICAL JOURNAL PLUS
(2021)
Article
Materials Science, Multidisciplinary
Z. Babamahdi, V. B. Svetovoy, D. T. Yimam, B. J. Kooi, T. Banerjee, J. Moon, S. Oh, M. Enache, M. Stohr, G. Palasantzas
Summary: The film thickness plays a crucial role in determining the Casimir and electrostatic forces of topological insulating Bi2Se3 films. Thicker films can approach the genuine Casimir force after voltage compensation, while strong electrostatic effects lead to gradual deviation from theory in thinner films.
Article
Chemistry, Multidisciplinary
Oleg A. Vasilyev, Emanuele Marino, Bas B. Kluft, Peter Schall, Svyatoslav Kondrat
Summary: Fine-tuning interactions between particles can influence the structure of charged nanoparticles deposited on a substrate, with critical Casimir interactions decreasing significantly at the substrate. Experiments and simulations show self-assembly of nanoparticles into crystalline clusters and potential formation of fractal-like nanoparticle gels and bicontinuous phases. This research provides exciting opportunities for studying complex structures in optoelectronics and photonics.
Article
Chemistry, Physical
Ivan Santamaria-Holek, Agustin Perez-Madrid
Summary: Using an innovative approach based on Planck's law, this study explores the common origin of the repulsive Casimir thermal pressure and heat exchange in nanogaps. By employing a scale transformation, the researchers demonstrate the validity of Planck's law in describing confined thermal radiation properties in nanoscale gaps. Analytical expressions for the Casimir thermal pressure and heat conductance are derived and compared with experimental data, showing remarkable agreement.
NANOSCALE HORIZONS
(2022)
Article
Multidisciplinary Sciences
Ying Wu, Mou Yan, Zhi-Kang Lin, Hai-Xiao Wang, Feng Li, Jian-Hua Jiang
Summary: This study reports the first experimental realization of an on-chip micromechanical metamaterial as a higher-order topological insulator for elastic waves at MHz. The higher-order topological phononic band gap is induced by band inversion at the Brillouin zone corner achieved by configuring orientations of elliptical pillars etched on the silicon chip. The experimental realization demonstrates the coexistence of topological edge and corner states induced by higher-order band topology in a single silicon chip.
Article
Engineering, Electrical & Electronic
Mihee Ji, Neil R. Taylor, Ivan Kravchenko, Pooran Joshi, Tolga Aytug, Lei R. Cao, M. Parans Paranthaman
Summary: This study demonstrated large-size vertical beta-Ga2O3 Schottky barrier diodes on a Si-doped n-type drift layer grown on a bulk Sn-doped beta-Ga2O3 substrate, with various device areas showing different breakdown voltages and ideality factors while maintaining relatively low specific on-state resistance.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Physics, Applied
Ying Pan, Rasmus E. Christiansen, Jerome Michon, Juejun Hu, Steven G. Johnson
Summary: Surface-enhanced Raman spectroscopy (SERS) is a powerful sensing method with the potential to detect single molecules, and topology optimization (TopOpt) can be used to design SERS substrates adhering to realistic fabrication constraints. By relaxing the fabrication minimum-feature-size constraint, TopOpt can be used to design SERS substrates with orders of magnitude larger enhancement factors. The results validate topology optimization as an effective method for engineering optimized SERS nanostructures adhering to fabrication limitations.
APPLIED PHYSICS LETTERS
(2021)
Article
Instruments & Instrumentation
Neil R. Taylor, Mihee Ji, Lei Pan, Praneeth Kandlakunta, Ivan Kravchenko, Pooran Joshi, Tolga Aytug, M. Parans Paranthaman, Lei R. Cao
Summary: In this study, Schottky barrier diodes were fabricated using Si-doped Ga2O3 epitaxial layer, showing good response to X-rays. The devices demonstrated fast response time and stability in X-ray detection through electrical performance testing.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
(2021)
Article
Optics
Alec M. Hammond, Ardavan Oskooi, Mo Chen, Zin Lin, Steven G. Johnson, Stephen E. Ralph
Summary: We present a photonics topology optimization (TO) package that can address a wide range of practical photonics design problems. The package incorporates robustness and manufacturing constraints and can scale to large devices and massive parallelism. It employs a hybrid algorithm that solves multiple frequency-domain TO problems using a mature time-domain (FDTD) package and is enhanced by new filter-design sources and material-interpolation methods.
Article
Optics
Zin Lin, Raphael Pestourie, Charles Roques-Carmes, Zhaoyi Li, Federico Capasso, Marin Soljacic, Steven G. Johnson
Summary: We introduce end-to-end inverse design for multi-channel imaging, which involves optimizing a nanophotonic frontend and an image-processing backend to extract depth, spectral, and polarization channels from a single monochrome image. We demonstrate that subwavelength-scale metasurface designs can easily distinguish similar wavelength and polarization inputs, unlike diffractive optics. Our proposed technique combines a single-layer metasurface frontend with an efficient Tikhonov reconstruction backend, requiring only a grayscale sensor. Through spontaneous demultiplexing, our method achieves multi-channel imaging by separating different channels into distinct spatial domains on the sensor. We present large-area metasurface designs for multi-spectral imaging, depth-spectral imaging, and all-in-one spectro-polarimetric-depth imaging, demonstrating robust reconstruction performance.
Article
Chemistry, Multidisciplinary
Troy C. Messina, Bernadeta R. Srijanto, Charles Patrick Collier, Ivan I. Kravchenko, Christopher Richards
Summary: Zero-mode waveguides (ZMWs) are widely used in single molecule fluorescence microscopy for their ability to enhance emitted light and study samples at physiological concentrations. A new method of ZMW production using focused ion beam (FIB) milling with gold ions is reported in this study, showing that ion-milled gold ZMWs exhibit similar plasmon-enhanced fluorescence as ZMWs fabricated with traditional techniques.
Article
Physics, Applied
Mohammed Benzaouia, John D. Joannopoulos, Steven G. Johnson, Aristeidis Karalis
Summary: This study presents general analytical criteria for designing standard filters and demonstrates the method of designing filter devices through specific unitary coupling ratios. By solving a nonlinear optimization problem, filter design can be achieved, with a focus on elliptic filters for optimal performance.
PHYSICAL REVIEW APPLIED
(2022)
Article
Multidisciplinary Sciences
Hanyu Zheng, Quan Liu, You Zhou, Ivan I. Kravchenko, Yuankai Huo, Jason Valentine
Summary: Rapid advances in deep learning have led to paradigm shifts in various fields, but the high computational requirements of digital neural networks result in increased energy consumption and limitations in real-time decision-making when computation resources are limited. This study demonstrates a meta-optic-based neural network accelerator that can off-load computationally expensive convolution operations into high-speed and low-power optics, achieving robust classification performance.
Article
Optics
Wenjie Yao, Francesc Verdugo, Henry O. Everit, Rasmus E. Christiansen, Steven G. Johnson
Summary: We propose a general framework for inverse design of nanopatterned surfaces that maximize surface-enhanced Raman spectra from randomly distributed molecules. Our optimized structures outperform coating with optimized spheres or bowtie structures by about 4 and 20 times, respectively, when considering nonlinear damage effects.
Article
Computer Science, Interdisciplinary Applications
Giuseppe Romano, Steven G. Johnson
Summary: In this study, a methodology for density-based topology optimization of non-Fourier thermal transport in nanostructures is introduced. It utilizes adjoint-based sensitivity analysis of the phonon Boltzmann transport equation (BTE) and a novel material interpolation technique called the transmission interpolation model (TIM). The approach is able to handle the interplay between real- and momentum-resolved material properties by parameterizing the material density with an interfacial transmission coefficient. This methodology allows for the systematic optimization of materials for heat management and conversion, as well as the design of devices where diffusive transport is not valid.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
Article
Optics
Hooman Barati Sedeh, Danilo G. Pires, Nitish Chandra, Jiannan Gao, Dmitrii Tsvetkov, Pavel Terekhov, Ivan Kravchenko, Natalia Litchinitser
Summary: Structured lights, such as beams with spin and orbital angular momenta and various polarizations, have attracted interest for their unique properties in optical and quantum communications, micromanipulation, and imaging. Additionally, structured optical materials have opened new opportunities for controlling light flow and sensing. However, the interaction between structured light and complex-shaped materials has not been fully explored.
LASER & PHOTONICS REVIEWS
(2023)
Article
Optics
Mohammed Benzaouia, A. D. Stone, Steven G. Johnson
Summary: In this study, a general analysis is presented for finding and characterizing nonlinear exceptional point (EP) lasers above threshold. The stability of the EP laser is confirmed through numerical analysis, and a new method for characterizing the EP laser is proposed.
Article
Engineering, Electrical & Electronic
Yuan Qin, Ming Xiao, Ruizhe Zhang, Qingyun Xie, Tomas Palacios, Boyan Wang, Yunwei Ma, Ivan Kravchenko, Dayrl P. Briggs, Dale K. Hensley, Bernadeta R. Srijanto, Yuhao Zhang
Summary: This work presents the fabrication of quasi-vertical GaN Schottky barrier diodes (SBDs) on a 6-inch Si substrate with a record-breaking breakdown voltage (BV) of over 1 kV. The novel use of a deep mesa in quasi-vertical devices allows for a self-aligned edge termination, and the mesa sidewall is covered by p-type nickel oxide (NiO) to reduce the surface field. The device exhibits a parallel-plane junction electric field of 2.8 MV/cm, along with low turn-on voltage and specific on-resistance. Additionally, it demonstrates excellent overvoltage robustness under continuous stress.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Optics
Sophie Fisher, Raphael Pestourie, Steven G. Johnson
Summary: This study presents a semianalytical framework for computing the coupling of radiative and guided waves in slowly varying surfaces. It fills the gap in current approximate methods by allowing the modeling of their coupling using a combination of two methods.
Article
Physics, Multidisciplinary
Lu Lu, Raphael Pestourie, Steven G. Johnson, Giuseppe Romano
Summary: This paper proposes a multifidelity neural operator based on deep neural networks, which can reduce the demand for high-fidelity data and achieve smaller errors in solving heat transport problems. By combining with genetic algorithms and topology optimization, it enables fast solvers and inverse design for the phonon Boltzmann transport equation (BTE).
PHYSICAL REVIEW RESEARCH
(2022)