BINA

We present novel photonic neuromorphic computing scheme working with incoherent light while capable implementing negative weighting for the neural network and obtaining reliable/accurate computing of the linear multiply-accumulate function necessary for neural networks applications.

The Leggett-Garg Inequality (LGI) constrains, under certain fundamental assumptions, the correlations between measurements of a quantity Q at different times. Here we analyze the LGI, and propose similar but somewhat more elaborate inequalities, employing a technique that utilizes the mathematical properties of correlation matrices, which was recently proposed in the context of nonlocal correlations. We also find that this technique can be applied to inequalities that combine correlations between different times (as in LGI) and correlations between different locations (as in Bell inequalities). All the proposed bounds include additional correlations compared to the original ones and also lead to a particular form of complementarity. A possible experimental realization and some applications are briefly discussed.

Bell inequalities are one of the cornerstones of quantum foundations, and fundamental tools for quantum technologies. Recently, the scientific community worldwide has put a lot of effort towards them, which culminated with loophole-free experiments. Nonetheless, none of the experimental tests so far was able to extract information on the full inequality from each entangled pair, since the wave function collapse forbids performing, on the same quantum state, all the measurements needed for evaluating the entire Bell parameter. We present here the first single-pair Bell inequality test, able to obtain a Bell parameter value for every entangled pair detected. This is made possible by exploiting sequential weak measurements, allowing to measure non-commuting observables in sequence on the same state, on each entangled particle. Such an approach not only grants unprecedented measurement capability, but also removes the need to choose between different measurement bases, intrinsically eliminating the freedom-of-choice loophole and stretching the concept of counterfactual-definiteness (since it allows measuring in the otherwise not-chosen bases). We also demonstrate how, after the Bell parameter measurement, the pair under test still presents a noteworthy amount of entanglement, providing evidence of the absence of (complete) wave function collapse and allowing to exploit this quantum resource for further protocols.

Perovskite photovoltaics offer a highly efficient and low-cost solar energy harvesting technology. However, the presence of lead (Pb) cations in photovoltaic halide perovskite (HaPs) materials is concerning, and quantifying the environmental hazard of accidental Pb2+ leaching into the soil is crucial for assessing the sustainability of this technology. Pb2+ from inorganic salts was previously found to remain in the upper soil layers due to adsorption. However, Pb-HaPs contain additional organic and inorganic cations, and competitive cation adsorption may affect Pb2+ retention in soils. Therefore, we measured, analyzed by simulations and report the depths to which Pb2+ from HaPs penetrates into 3 types of agricultural soil. Most of the HaP-leached Pb2+ is found to be retained already in the first cm of the soil columns, and subsequent rain events do not induce Pb2+ penetration below the first few cm of soil surface …

Memristive devices based on correlated Mott materials have great potential for memory applications, and specifically neuromorphic computations, due to their simple structure, miniaturization capabilities, power efficiency, and operation speeds. For these reasons, many efforts are made to design improved synaptic devices based on Mott materials. This work demonstrates a nonvolatile memristive three-terminal transistor based on the correlated oxide VO 2, which has a (Mott) metal-insulator transition near room temperature. An ultrathin VO 2 layer is incorporated in a metal-oxide-semiconductor field-effect geometry using alumina as the gate dielectric. A field effect is demonstrated to modify the channel’s resistance in a nonvolatile and reversible fashion. However, only when the gate voltage is applied at the metallic state of the VO 2 does the resistance of the insulating state change. Thus, the metallic and insulating …

We demonstrate that the direction of current rectification via one of nature’s most efficient light-harvesting systems, the photosystem 1 complex (PS1), can be controlled by its orientation on Au substrates. Molecular self-assembly of the PS1 complex using four different linkers with distinct functional head groups that interact by electrostatic and hydrogen bonds with different surface parts of the entire protein PS1 complex was used to tailor the PS1 orientation. We observe an orientation-dependent rectification in the current–voltage characteristics for linker/PS1 molecule junctions. Results of an earlier study using a surface two-site PS1 mutant complex having its orientation set by covalent binding to the Au substrate supports our conclusion. Current–voltage–temperature measurements on the linker/PS1 complex indicate off-resonant tunneling as the main electron transport mechanism. Our ultraviolet photoemission …

The Leggett-Garg Inequality (LGI) constrains, under certain fundamental assumptions, the correlations between measurements of a quantity Q at different times. Here we analyze the LGI, and propose similar but somewhat more elaborate inequalities, employing a technique that utilizes the mathematical properties of correlation matrices, which was recently proposed in the context of nonlocal correlations. We also find that this technique can be applied to inequalities that combine correlations between different times (as in LGI) and correlations between different locations (as in Bell inequalities). All the proposed bounds include additional correlations compared to the original ones and also lead to a particular form of complementarity. A possible experimental realization and some applications are briefly discussed.

Time-lenses can image ultrafast signals in time. Placing them in a 2-f configuration leads to Fourier transform of the input signal and ultrafast spectroscopy. We utilized two time-lenses in a 4-f configuration and formed an interferometer in the time domain. Our time lenses are based on four-wave mixing process, generating an idler beam which serves as the output. The output from the first time-lens is the input to the second time-lens. At the output of the second time-lens, we get an interference between the signal beams of both time-lenses and the idler beams of both time-lenses. This interference is sensitive to ultrafast phase shifts in time and can lead to interfere signals in different times. This interferometer is good for quantum imaging, and studying the temporal structure of entangled photons. In this talk we will demonstrate the interferometer, how we exploit time-lenses for interferometry, the application of the …

The coherent dynamics in networks of coupled oscillators is of great interest in wave-physics since the coupling produces various dynamical effects, such as coherent energy exchange (beats) between the oscillators. However, it is common wisdom that these coherent dynamics are transients that quickly decay in active oscillators (eg lasers) since pump saturation causes mode competition that results, for homogeneous gain, in the prevalence of the single winning mode. We observe that pump saturation in coupled parametric oscillators counter-intuitively encourages the multi-mode dynamics of beating and indefinitely preserves it, despite the existence of mode competition. We explore in detail the coherent dynamics of a pair of coupled parametric oscillators with a shared pump and arbitrary coupling in a radio frequency (RF) experiment, as well as in simulation. Specifically, we realize two parametric oscillators as …

The later stages of cooling of molecules and clusters in the interstellar medium are dominated by emission of vibrational infrared radiation. With the development of cryogenic storage it has become possible to experimentally study these processes. Recent storage ring results demonstrate that intramolecular vibrational redistribution takes place within the cooling process, and an harmonic cascade model has been used to interpret the data. Here we analyze this model and show that the energy distributions and the photon emission rates develop into near-universal functions that can be characterized with only a few parameters, irrespective of the precise vibrational spectra and oscillator strengths of the systems. We show that the photon emission rate and emitted power vary linearly with total excitation energy with a small offset. The time developments of ensemble internal energy distributions are calculated with …

In many industrial settings, films of polymers such as polypropylene (PP) and polyethylene terephthalate (PET) require surface treatment due to poor wettability and low surface energy. Here, a simple process is presented to prepare durable thin coatings composed of polystyrene (PS) core, PS/SiO2 core–shell, and hollow SiO2 micro/nanoparticles onto PP and PET films as a platform for various potential applications. Corona-treated films were coated with a monolayer of PS microparticles by in situ dispersion polymerization of styrene in ethanol/2-methoxy ethanol with polyvinylpyrrolidone as stabilizer. A similar process on untreated polymeric films did not yield a coating. PS/SiO2 core–shell coated microparticles were produced by in situ polymerization of Si(OEt)4 in ethanol/water onto a PS-coated film, creating a raspberry-like morphology with a hierarchical structure. Hollow porous SiO2-coated microparticles onto …

X-ray optical wave mixing is a nonlinear diffraction method that gives direct information about the Ångstrom and femtosecond-scale structure of the local optically-induced charge density in bulk solids, information unavailable to purely optical methods. The first measurements of wave mixing between x rays and optical photons were reported for single crystal diamond [Glover et al., Nature 488, 603 (2012)]. Here we report x-ray optical wave mixing experiments using the Swiss-FEL and LCLS hard x-ray free-electron lasers. To measure the wave-mixing signal we use silicon crystal optics to monochromate the free-electron laser output and analyze the energy-angle dependent wave-mixing signal while rejecting the elastic background. The results include the first measurements from silicon and the first measurement of the higher-order wave-mixing process generating the sum frequency of two optical and one x-ray …

Geometry, an ancient yet vibrant branch of mathematics, has important and far-reaching impacts on various disciplines such as art, science, and engineering. Here, we introduce an emerging concept dubbed “geometric deep optical sensing” that is based on a number of recent demonstrations in advanced optical sensing and imaging, in which a reconfigurable sensor (or an array thereof) can directly decipher the rich information of an unknown incident light beam, including its intensity, spectrum, polarization, spatial features, and possibly angular momentum. We present the physical, mathematical, and engineering foundations of this concept, with particular emphases on the roles of classical and quantum geometry and deep neural networks. Furthermore, we discuss the new opportunities that this emerging scheme can enable and the challenges associated with future developments.

In fluorescence-based biosensing applications, to increase optical detection sensitivity, time-resolved measurements are extensively used. Magnetic modulation biosensing (MMB) is a novel, fast, and sensitive detection technology for various applications. While this technology provides high sensitivity detection of biomarkers, to date, only the time resolved signal was analyzed. Here, we use for the first time both time-resolved and spatial-resolved measurements and show that this combination drastically improves the sensitivity of an MMB-based assay.

In many industrial settings, films of polymers such as polypropylene (PP) and polyethylene terephthalate (PET) require surface treatment due to poor wettability and low surface energy. Here, a simple process is presented to prepare durable thin coatings composed of polystyrene (PS) core, PS/SiO2 core–shell, and hollow SiO2 micro/nanoparticles onto PP and PET films as a platform for various potential applications. Corona-treated films were coated with a monolayer of PS microparticles by in situ dispersion polymerization of styrene in ethanol/2-methoxy ethanol with polyvinylpyrrolidone as stabilizer. A similar process on untreated polymeric films did not yield a coating. PS/SiO2 core–shell coated microparticles were produced by in situ polymerization of Si(OEt)4 in ethanol/water onto a PS-coated film, creating a raspberry-like morphology with a hierarchical structure. Hollow porous SiO2-coated microparticles onto …

K04. 00003: Zwitterists: Photo-patternable Polymer Zwitterions for Interfacial Dipole Doping of Monolayer Graphene*

Rapid, highly sensitive, and high-throughput detection of biomarkers at low concentrations is invaluable for early diagnosis of various diseases. In many sensitive immunoassays the protocol is time consuming and requires a complicated and expensive detection system. Here, we demonstrate a high-throughput optical modulation biosensing (ht-OMB) system, which enables reading a 96-well plate within 10 minutes. Using the system, to detect human Interleukin-8, we demonstrated a limit of detection of 0.14 ng/L and a 4-log dynamic range. Testing 94 RNA extracts from 36 confirmed RT-qPCR SARS-CoV-2-positive patients (C_t≤40) and 58 confirmed RT-qPCR SARS-CoV-2-negative individuals resulted in 100% sensitivity and 100% specificity.

Pancreatic ductal adenocarcinoma (PDA) is characterized by aggressive local invasion and metastatic spread, leading to high lethality. Although driver gene mutations during PDA progression are conserved, no specific mutation is correlated with the dissemination of metastases–. Here we analysed RNA splicing data of a large cohort of primary and metastatic PDA tumours to identify differentially spliced events that correlate with PDA progression. De novo motif analysis of these events detected enrichment of motifs with high similarity to the RBFOX2 motif. Overexpression of RBFOX2 in a patient-derived xenograft (PDX) metastatic PDA cell line drastically reduced the metastatic potential of these cells in vitro and in vivo, whereas depletion of RBFOX2 in primary pancreatic tumour cell lines increased the metastatic potential of these cells. These findings support the role of RBFOX2 as a potent metastatic suppressor in …

The advent of functional devices based on two-dimensional (2D) materials has further intensified the interest in the latter. However, the fabrication of structures using layered materials remains a key challenge. Recently, we proposed the so-called “Laser-Induced Transfer” method (LIT), as a digital and solvent-free approach for the high-resolution and intact transfer of 2D materials’ pixels. Here, we will further highlight the versatility of LIT by reporting results on the high-quality digital transfer of graphene and MoS2. These materials have emerged in the field of nanoelectronics, sensors and photonics due to their unique optoelectronic properties, but their high-quality transfer remains a hurdle. The quality of the transferred films has been confirmed with systematic characterization based on Scanning Electron Microscopy and Raman spectroscopy, as well as mobility’s extraction. Then we will present how the laser …

This review article summarizes the comprehensive work that was done in our laboratory in recent years, as-well-as other reports, on the various aspects of sonochemistry of molten gallium. The low mp (29.8 °C) of gallium enables its melting in warm water, aqueous solutions and organic liquids. This opened a new research direction that focused on the chemical and physical properties of gallium particles that were formed in such media. It includes their interactions with water and with organic and inorganic solutes in aqueous solutions and with carbon nanoparticles. Formation of nanoparticles of liquid gallium alloys was also reported.

In nanophotonic, small mode volumes, narrow resonance linewidths and field enhancements, fundamentally scales with refractive index values and are key for many implementations involving light-matter interactions. Topological insulators (TI) are a class of insulating materials that host topologically protected surface states, some of which exhibit very high permittivity values. In this talk, I will discuss our latest results on Bi2Te3 and Bi2Se3 TI nanostructures. Using polarized far-field and near field nanospectroscopy we reveal that Bi2Se3 nanobeams exhibit mid-infrared resonant modes with 2π 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.