BINA

Geometric phase is a key player in many areas of quantum science and technology. In this review article, we outline several foundational aspects of quantum geometric phases and their relations to classical geometric phases. We then discuss how the Aharonov-Bohm and Sagnac effects fit into this context. Moreover, we present a concise overview of technological applications of the latter, with special emphasis on gravitational sensing, like in gyroscopes and gravitational wave detectors.

Metal–semiconductor interfaces are ubiquitous in modern electronics. These quantum-confined interfaces allow for the formation of atomically thin polarizable metals and feature rich optical and optoelectronic phenomena, including plasmon-induced hot-electron transfer from metal to semiconductors. Here, we report on the metal–semiconductor interface formed during the intercalation of zero-valent atomic layers of tin (Sn) between layers of MoS2, a van der Waals layered material. We demonstrate that Sn interaction leads to the emergence of gap states within the MoS2 band gap and to corresponding plasmonic features between 1 and 2 eV (0.6–1.2 μm). The observed stimulation of the photoconductivity, as well as the extension of the spectral response from the visible regime toward the mid-infrared suggests that hot-carrier generation and internal photoemission take place.

Among extensively studied Li‐ion cathode materials, LiCoO2 (LCO) remains dominant for portable electronic applications. Although its theoretical capacity (274 mAh g−1) cannot be achieved in Li cells, high capacity (≤240 mAh g−1) can be obtained by raising the charging voltage up to 4.6 V. Unfortunately, charging Li‐LCO cells to high potentials induces surface and structural instabilities that result in rapid degradation of cells containing LCO cathodes. Yet, significant stabilization is achieved by surface coatings that promote formation of robust passivation films and prevent parasitic interactions between the electrolyte solutions and the cathodes particles. In the search for effective coatings, the authors propose RbAlF4 modified LCO particles. The coated LCO cathodes demonstrate enhanced capacity (>220 mAh g−1) and impressive retention of >80/77% after 500/300 cycles at 30/45 °C. A plausible mechanism …

The optimal performance of organic electrodes for aqueous batteries requires their full compatibility with selected electrolyte solutions. Electrode materials having 1–3-dimensional structures of variable rigidity possess a confined space in their structure filled with water and electrolyte solutions. Depending on the rigidity and confined space geometry, insertion and extraction of ions into electrode structures are often coupled with incorporation/withdrawal of water molecules. Aside from the scientific interest in understanding the charging mechanism of such systems, co-insertion of solvent molecules affects strongly the charge storage capability of the electrodes for energy storage devices. We present herein in situ electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D) investigations of polyaniline (PANI) electrodes operating in various aqueous Na+-containing electrolytes, namely, Na2SO4 …

Increasing the production capacity of electrical energy to fulfill the continuously rising global demand, while simultaneously trying to avoid greenhouse gas emissions in the process, and being environmentally sound, is one of the largest challenges of this era.One way to achieve it is to rely on hydrogen for energy storage. Nowadays, most of the hydrogen produced is mainly from fossil fuels, and the emission of detrimental gasses is only shifted. To get to a true green hydrogen, it is necessary to produce it in emissions-free processes.One method to achieve this is to use renewable energies in combination with electrochemical water electrolyzers, in which two distinct chemical reactions take place: the cathodic hydrogen evolution reaction (HER) and the anodic oxygen evolution reaction (OER). Both reaction require catalysts to execute at high rates, and while the HER is considered to be relatively facile and takes …

Experimental characterization and applications of forward Brillouin scattering in various types of optical fibers are presented. Measurements are compared with the predictions of analysis and calculations whenever possible. Results include the forward Brillouin scattering spectra of bare and coated single-mode fibers, multi-core fibers, and polarization-maintaining fibers. Both intra-modal and inter-modal process in polarization-maintaining fibers are reported. The contributions of radial and torsional-radial modes are identified and classified. The interplay of forward Brillouin scattering and the Kerr effect is characterized as well. Position-integrated, point-measurement, and spatially distributed analyses of liquid media outside the fiber are demonstrated. The sensing of surrounding media is enabled by forward Brillouin scattering processes, even though guided light does not come in contact with such media. The …

Forward Brillouin scattering interactions support the sensing and analysis of media outside the cladding boundaries of standard fibers, where light cannot reach. Quantitative point-sensing based on this principle has yet to be reported. In this work, we report a forward Brillouin scattering point-sensor in a commercially available, off-the-shelf multi-core fiber. Pump light at the inner, on-axis core of the fiber is used to stimulate a guided acoustic mode of the entire fiber cross-section. The acoustic wave, in turn, induces photoelastic perturbations to the reflectivity of a Bragg grating inscribed in an outer, off-axis core of the same fiber. The measurements successfully analyze refractive index perturbations on the tenth decimal point and distinguish between ethanol and water outside the centimeter-long grating. The measured forward Brillouin scattering linewidths agree with predictions. The acquired spectra are unaffected by forward Brillouin scattering outside the grating region. The results add point-analysis to the portfolio of forward Brillouin scattering optical fiber sensors.

Among extensively studied Li‐ion cathode materials, LiCoO2 (LCO) remains dominant for portable electronic applications. Although its theoretical capacity (274 mAh g−1) cannot be achieved in Li cells, high capacity (≤240 mAh g−1) can be obtained by raising the charging voltage up to 4.6 V. Unfortunately, charging Li‐LCO cells to high potentials induces surface and structural instabilities that result in rapid degradation of cells containing LCO cathodes. Yet, significant stabilization is achieved by surface coatings that promote formation of robust passivation films and prevent parasitic interactions between the electrolyte solutions and the cathodes particles. In the search for effective coatings, the authors propose RbAlF4 modified LCO particles. The coated LCO cathodes demonstrate enhanced capacity (>220 mAh g−1) and impressive retention of >80/77% after 500/300 cycles at 30/45 °C. A plausible mechanism …

In the first chapter of this book, the opto-mechanical effect of forward Brillouin scattering is introduced within a broader context of propagation effects in fibers and of interactions between optical and acoustic waves. A review of linear and nonlinear scattering phenomena is provided, including the mechanisms of Rayleigh, Raman, and Brillouin scattering, and the optical Kerr effect. Scattering from short-period and long-period grating devices is discussed as well. The potential applications and implications of the various mechanisms in optical fiber communications, sensing, signal processing, and lasing are briefly addressed. Next, the physical principles of opto-mechanics are introduced. These include the stimulation of elastic waves by electrostrictive bulk forces and radiation pressures and the scattering of optical waves through photoelasticity and moving boundary effects. Specific formalisms are developed for the …

The seven-transmembrane superfamily member 3 protein (TM7SF3) is a p53-regulated homeostatic factor that attenuates cellular stress and the unfolded protein response. Here we show that TM7SF3 localizes to nuclear speckles; eukaryotic nuclear bodies enriched in splicing factors. This unexpected location for a trans-membranal protein enables formation of stable complexes between TM7SF3 and pre-mRNA splicing factors including DHX15, LARP7, HNRNPU, RBM14, and HNRNPK. Indeed, TM7SF3 regulates alternative splicing of >330 genes, mainly at the 3’end of introns by directly modulating the activity of splicing factors such as HNRNPK. These effects are observed both in cell lines and primary human pancreatic islets. Accordingly, silencing of TM7SF3 results in differential expression of 1465 genes (about 7% of the human genome); with 844 and 621 genes being up- or down-regulated, respectively …

Polarization-maintaining fibers support guided acoustic modes that are more complex than those of single-mode fibers, due to the presence of strain rods. Forward Brillouin scattering interactions in those fibers can be intra-modal as well as inter-modal. Intra-modal interactions involve the stimulation of guided acoustic waves by a pair of optical fields that co-propagate in a common principal axis. The intra-modal processes can lead to phase modulation of co-polarized optical probe signals, similar to standard single-mode fibers. The forward Brillouin scattering spectra differ between the two axes. In addition, acoustic modes stimulated through an intra-modal process in one axis may also modulate a probe wave in the orthogonal axis. Such inter-polarization cross-phase modulation is analogous to the dynamic gratings of backward Brillouin scattering in polarization-maintaining fibers. In inter-modal forward Brillouin …

Electron paramagnetic resonance (EPR) spectroscopy has become a promising structural biology tool to resolve complex and dynamic biological mechanisms in-vitro and in-cell. Here, we focus on the advantages of continuous wave (CW) and pulsed EPR distance measurements to resolve transcription processes and protein-DNA interaction. The wide range of spin-labeling approaches that can be used to follow structural changes in both protein and DNA render EPR a powerful method to study protein-DNA interactions and structure–function relationships in other macromolecular complexes. EPR-derived data goes well beyond static structural information and thus serves as the method of choice if dynamic insight is needed. Herein, we describe the conceptual details of the theory and the methodology and illustrate the use of EPR to study the protein-DNA interaction of the copper-sensitive transcription factor, CueR.

Background: The cost of heart failure hospitalizations in the US alone is over USD 10 billion per year. Over 4 million Americans are hospitalized every year due to heart failure (HF), with a median length of stay of 4 days and an in-hospital mortality rate that exceeds 5%. Hospitalizations of patients with HF can be prevented by early detection of lung congestion. Our study assessed a new contact-free optical medical device used for the early detection of lung congestion. Methods: The Gili system is an FDA-cleared device used for measuring chest motion vibration data. Lung congestion in the study was assessed clinically and verified via two cardiologists. An algorithm was developed using machine learning techniques, and cross-validation of the findings was performed to estimate the accuracy of the algorithm. Results: A total of 227 patients were recruited (101 cases vs. 126 controls). The sensitivity and specificity for the device in our study were 0.91 (95% CI: 0.86–0.93) and 0.91 (95% CI: 0.87–0.94), respectively. In all instances, the observed estimates of PPVs and NPVs were at least 0.82 and 0.90, respectively. The accuracy of the algorithm was not affected by different covariates (including respiratory or valvular conditions). Conclusions: This study demonstrates the efficacy of a contact-free optical device for detecting lung congestion. Further validation of the study results across a larger and precise scale is warranted.

In this chapter, the analysis of forward stimulated Brillouin scattering in fibers comprised of multiple cores is presented. In such multi-core fibers, guided acoustic waves may be stimulated by optical fields in one core and induce photoelastic scattering of light waves in a different one. The photoelastic scattering leads to cross-phase modulation among optical fields in spatially distinct cores, which is mediated by the stimulation of guided acoustic modes. Cross-phase modulation may take place even among cores that are spaced far apart, where the direct coupling of optical power is arbitrarily weak. The process is quantified in terms of the spectrum of forward Brillouin scattering coefficient, defined earlier with respect to single-mode fibers. The spectrum of cross-phase modulation between the inner, on-axis core and an outer, off-axis core is mediated by guided acoustic modes of radial symmetry and torsional-radial …

The velocity distribution of a classical gas of atoms in thermal equilibrium is the normal Maxwell distribution. It is well known that for sub-recoiled laser cooled atoms L\'evy statistics and deviations from usual ergodic behaviour come into play. Here we show how tools from infinite ergodic theory describe the cool gas. Specifically, we derive the scaling function and the infinite invariant density of a stochastic model for the momentum of laser cooled atoms using two approaches. The first is a direct analysis of the master equation and the second following the analysis of Bertin and Bardou using the lifetime dynamics. The two methods are shown to be identical, but yield different insights into the problem. In the main part of the paper we focus on the case where the laser trapping is strong, namely the rate of escape from the velocity trap is for and . We construct a machinery to investigate the time averages of physical observables and their relation to ensemble averages. The time averages are given in terms of functionals of the individual stochastic paths, and here we use a generalisation of L\'evy walks to investigate the ergodic properties of the system. Exploring the energy of the system, we show that when it exhibits a transition between phases where it is either an integrable or non integrable observable, with respect to the infinite invariant measure. This transition corresponds to very different properties of the mean energy, and to a discontinuous behaviour of the fluctuations. Since previous experimental work showed that both and are attainable we believe that both phases could be explored also experimentally.

Protein degradation mediated by the ubiquitin-proteasome pathway regulates signaling events in many physiological and pathological conditions. In vitro degradation assays have been instrumental in the understanding of how cell proliferation and other fundamental cellular processes are regulated. These assays are direct, time-specific and highly informative but also laborious, typically relying on low-throughput polyacrylamide gel-electrophoresis followed by autoradiography or immunoblotting. We present protein degradation on chip (pDOC), a MITOMI-based integrated microfluidic technology for discovery and analysis of proteins degradation in cell-free extracts. The platform accommodates hundreds of microchambers on which protein degradation is assayed quickly, simultaneously and using minute amounts of reagents in one or many physiochemical environments. Essentially, pDOC provides a sensitive …

The Cramer-Rao bound, satisfied by classical Fisher information, a key quantity in information theory, has been shown in different contexts to give rise to the Heisenberg uncertainty principle of quantum mechanics. In this paper, we show that the identification of the mean quantum potential, an important notion in Bohmian mechanics, with the Fisher information, leads, through the Cramer-Rao bound, to an uncertainty principle which is stronger, in general, than both Heisenberg and Robertson-Schrodinger uncertainty relations, allowing to experimentally test the validity of such an identification.

Silicon-photonic integrated circuits are a pivotal technology for the continued growth of data communications. A main task of silicon photonics is the wavelength division multiplexing of communication channels to aggregate bandwidths that exceed the working rates available in electronics. In this work, we design and implement a 16-channel, wavelength division multiplexing device in silicon-on-insulator. The device operates at the O-band wavelengths, centered at 1310 nm, which are favored by many data center applications. The spacing between adjacent channels is 0.96 nm (167 GHz), close to those of dense wavelength division multiplexing standards in the 1550 nm wavelength range (C band). The layout consists of 15 Mach-Zehnder interferometers, cascaded in a four-stage tree topology. The differential phase delay within each interferometer is precisely trimmed post-fabrication, through local illumination of a photosensitive upper cladding layer of As 2 Se 3 chalcogenide glass. Trimming is performed subject to closed-loop feedback of transfer functions measurements. The devices can be useful in data center optical communications.

A superconducting (SC) mixed state occurs in type-II superconductors where the upper critical field H c 2 is higher than the thermodynamic critical field H c. When an applied field is in between these fields, the free energy depends weakly on the order parameter which therefore can be small (SC state) or zero (normal state) at different parts of the sample. In this paper we demonstrate how a normal state along a line traversing a superconductor can be turned on and off externally in zero field. The concept is based on a long, current-carrying excitation coil, piercing a ring-shaped superconductor. The ring experiences zero field, but the vector potential produced by the coil generates a circular current that destroys superconductivity along a radial line starting at preexisting nucleation points in the sample. Unlike the destruction of superconductivity with magnetic field, the vector potential method is reversible and …

In nanophotonics, small mode volume and high-quality factor (Q-factor) resonances fundamentally scales with high refractive index values. Topological insulators (TI) are a new class of materials possessing narrow bulk bandgap and gapless Dirac surface states, and exhibit ultra high permittivity values. In this work, I will discuss our latest results on Bi2Te3 and Bi2Se3 TI meta-optics. Using polarized far-field and near field Nanospectroscopy we reveal that Bi2Se3 nanobeams exhibit mid-infrared resonant modes with 2pi phase shifts across the resonance. We further demonstrate that Bi2Te3 metasurfaces exhibit deep subwavelength resonant modes utilizing their record high index value peaking at n~11.

The changes occurring in mRNA organization during nucleo-cytoplasmic transport and export, are not well understood. Moreover, directionality of mRNA passage through the nuclear pore complex (NPC) has not been examined within individual NPCs. Here we find that an mRNP is compact during nucleoplasmic travels compared to a more open structure after transcription and at the nuclear periphery. Compaction levels of nuclear transcripts can be modulated by varying levels of SR proteins and by changing genome organization. Nuclear mRNPs are mostly rod-shaped with distant 5'/3'-ends, although for some, the ends are in proximity. The latter is more abundant in the cytoplasm and can be modified by translation inhibition. mRNAs and lncRNAs exiting the NPC exhibit predominant 5’-first export. In some cases, several adjacent NPCs are engaged in export of the same mRNA suggesting 'gene gating' …