TAU Nanocenter

Control over the joint spectral amplitude of a photon pair has proved highly desirable for many quantum applications, since it contains the spectral quantum correlations, and has crucial effects on the indistinguishability of photons, as well as promising emerging applications involving complex quantum functions and frequency encoding of qudits. Until today, this has been achieved by engineering a single degree of freedom, either by custom poling nonlinear crystal or by shaping the pump pulse. We present a combined approach where two degrees of freedom, the phase-matching function, and the pump spectrum, are controlled. This approach enables the two-dimensional control of the joint spectral amplitude, generating a variety of spectrally encoded quantum states - including frequency uncorrelated states, frequency-bin Bell states, and biphoton qudit states. In addition, the joint spectral amplitude is controlled by photon bunching and anti-bunching, reflecting the symmetry of the phase-matching function.

Cavity quantum electrodynamics (QED), wherein a quantum emitter is coupled to electromagnetic cavity modes, is a powerful platform for implementing quantum sensors, memories, and networks. However, due to the fundamental tradeoff between gate fidelity and execution time, as well as limited scalability, the use of cavity-QED for quantum computation was overtaken by other architectures. Here, we introduce a new element into cavity-QED - a free charged particle, acting as a flying qubit. Using free electrons as a specific example, we demonstrate that our approach enables ultrafast, deterministic and universal discrete-variable quantum computation in a cavity-QED-based architecture, with potentially improved scalability. Our proposal hinges on a novel excitation blockade mechanism in a resonant interaction between a free-electron and a cavity polariton. This nonlinear interaction is faster by several orders of magnitude with respect to current photon-based cavity-QED gates, enjoys wide tunability and can demonstrate fidelities close to unity. Furthermore, our scheme is ubiquitous to any cavity nonlinearity, either due to light-matter coupling as in the Jaynes-Cummings model or due to photon-photon interactions as in a Kerr-type many-body system. In addition to promising advancements in cavity-QED quantum computation, our approach paves the way towards ultrafast and deterministic generation of highly-entangled photonic graph states and is applicable to other quantum technologies involving cavity-QED.

The Stern-Gerlach experiment, a seminal quantum physics experiment, demonstrated the intriguing phenomenon of particle spin quantization, leading to applications in matter-wave interferometry and weak-value measurements. Over the years, several optical experiments have exhibited similar behavior to the Stern-Gerlach experiment, revealing splitting in both spatial and angular domains. Here we show, theoretically and experimentally, that the Stern-Gerlach effect can be extended into the time and frequency domains. By harnessing Kerr nonlinearity in optical fibers, we couple signal and idler pulses using two pump pulses, resulting in the emergence of two distinct eigenstates whereby the signal and idler are either in phase or out of phase. This nonlinear coupling emulates a synthetic magnetization, and by varying it linearly in time, one eigenstate deflects towards a higher frequency, while the other deflects …

More than three decades after the inception of electron spin-based information encoding inspired by nonlinear electro-optic devices, we present a complementary approach: nonlinear optical devices directly inspired by spintronics. We theoretically propose an all-optical spin-valve device and a spin-dependent beam splitter, where the optical pseudospin is a superposition of signal and idler beams undergoing a sum-frequency generation process inside a 2D nonlinear photonic crystal. We delve into the operation of these devices, examining key properties such as the transmission angle and splitting ratio, optically controlled by the pump beam. Our findings open new avenues for both classical and quantum optical information processing in the frequency domain.

This study demonstrates the use of a MnO2-coated gas-permeable membrane for efficient radical delivery to water. MnO2 of various morphologies─including nanowires (NW), nanosheets (NS) and nanoflowers (NF)─were synthesized, characterized, and evaluated according to their catalytic ozonation. In the presence of dissolved ozone, all forms of suspended MnO2 resulted in elevated hydroxyl radical exposure but still differed across morphologies. MnO2 NS resulted in a more efficient catalytic ozonation per mass and was thus synthesized on gas-permeable membrane tubes as a proof-of-concept. Polydimethylsiloxane (PDMS) membrane tubing was used as a platform, as it has been shown to enable effective passive diffusion of ozone driven by concentration gradients. The coated membrane allowed direct hydroxyl radical generation in a two-step process. First, the gaseous ozone passes through the inner …

Groundwater contamination by widespread and persistent organic compounds requires extensive treatment efforts, for example by in-situ chemical oxidation (ISCO). In this study, we investigated ozone mass transfer and removal mechanisms of ozone-resistant monocyclic aromatic and non-aromatic compounds in a novel in-situ treatment method using ozone-permeable membranes as reactive barrier. Initial batch experiments confirmed fast depletion of ozone in presence of sub-stoichiometric benzoic acid (BA), in contrast to the non-aromatic 1,4-dioxane (DIOX), where ozone depleted much slower. Simulated in-situ membrane ozonation treatment of contaminated groundwater led to lower removal of 5 mg L-1 BA (52.7%) compared to DIOX (60.6%). Inhibited removal of BA compared to additional batch experiments could be explained by quick depletion of ozone by reactive intermediates on the membrane surface …

Cardiac monitoring after heart surgeries is crucial for health maintenance and detecting postoperative complications early. However, current methods like rigid implants have limitations, as they require performing second complex surgeries for removal, increasing infection and inflammation risks, thus prompting research for improved sensing monitoring technologies. Herein, we introduce a nanosensor platform that is biodegradable, biocompatible, and integrated with multifunctions, suitable for use as implants for cardiac monitoring. The device has two electrochemical biosensors for sensing lactic acid and pH as well as a pressure sensor and a chemiresistor array for detecting volatile organic compounds. Its biocompatibility with myocytes has been tested in vitro, and its biodegradability and sensing function have been proven with ex vivo experiments using a three-dimensional (3D)-printed heart model and 3D …

The growing volumes of metal wastewater produced by industry require more efficient techniques for metal recovery. Biosorption is an attractive and desirable method for metal recovery because it avoids the additional chemicals beyond the sorbent. Mucin glycoprotein is a natural bioresource that can potentially adsorb and reduce precious metals. In this study, we examine the ability of mucin to recover gold from a mixed-metals solution in an acidic environment modeling industrial wastewater. We show that selectivity in the adsorption of the metals—and particularly precious metals—is driven by the metal's chemical properties and affinity to mucin. The ability of mucin to reduce gold ions and transform them into nanoparticles was also investigated both in mixed-metal solutions and isolated-metal solutions and with two different forms of mucin (dissolved and nanofibers). Lastly, the recovered gold NPs were used in …

Coherent cathodoluminescence (CL)–electromagnetic radiation driven by free electrons–offers miniature, tunable light sources across a wide spectrum [1], and plays a vital role in the emerging field of free-electron quantum optics [2]. With the goal of variable chip-scale sources in mind [3, 4], efficient coupling between free electrons and light is crucial. Quantum efficiency, on the one hand, has received increased attention in the past few years, and can be increased via phase-matching [5] or resonant amplification [6]. On the other hand, improvements in energy efficiency–the relative part of the electron energy carried by the photon–has stagnated thus far, due to deteriorating beam parameters, electromagnetic losses and limited collection efficiencies [7]. A promising way to operate at low electron energy and enhance efficiency is through the Smith Purcell (SP) effect [8]–the coherent emission of photons by a free …

We report on a three-slit experiment in the presence of a linear potential with surface gravity water waves. For these classical waves, we reconstruct the Bohm trajectories as well as the corresponding quantum potentials.

We report on a three-slit experiment in the presence of a linear potential with surface gravity water waves. For these classical waves, we reconstruct the Bohm trajectories as well as the corresponding quantum potentials.

Constantly raising microplastic (MP) contamination of water sources poses a direct threat to the gentle balance of the marine environment. This study focuses on a multifactor hazard evaluation of conventional (polyethylene - PE, polypropylene - PP, and polystyrene - PS) and alternative (polyethylene terephthalate with 25 % or 50 % recycled material and polylactic acid) plastics. The risk assessment framework explored included MP abundance, water acidification potential, surface oxidation, fragmentation, and bacterial growth inhibition. Based on MP monitoring campaigns worldwide, we conclude that PE-based plastics are the most abundant MPs in water samples (comprise up to 82 % the MP in those samples). A year-long weathering experiment showed that PS-based and PP-based plastics were oxidized to a higher extent, resulting in the highest water acidification with pH reduction of up to three orders of …

Multiple catalytic oxidation processes involving new synthesized materials have recently been examined to replace conventional oxidative treatment methods for water purification, but upscaling and demonstration stages are mostly lacking, which hinders their practical implementation. In this study, we introduce a novel catalytic process where peroxymonosulfate (PMS) is activated by MnO2 surfaces that are attached on natural sand as part of a catalytic filtration column (CFC). PMS decomposition in the CFC was stable during steady-state filter operation with different natural waters (tap water and secondary effluent) and sulfate radicals were identified as main radical species. Complete oxidation (>99 %) of 10 mg/L rhodamine B in tap water could be achieved with PMS concentrations as low as 0.2 mM and a residence time of less than 3 min. Furthermore, unselective oxidation of various recalcitrant and …

The survival and function of tissues depend on appropriate vascularization. Blood vessels of the tissues supply oxygen, and nutrients and remove waste and byproducts. Incorporating blood vessels into engineered tissues is essential for overcoming diffusion limitations, improving tissue function, and thus facilitating the fabrication of thick tissues. Here, we present a modified ECM bioink, with enhanced mechanical properties and endothelial cell-specific adhesion motifs, to serve as a building material for 3D printing of a multiscale blood vessel network. The bioink is composed of natural ECM and alginate conjugated with a laminin adhesion molecule motif (YIGSR). The hybrid hydrogel was characterized for its mechanical properties, biochemical content, and ability to interact with endothelial cells. The pristine and modified hydrogels were mixed with induced pluripotent stem cells derived endothelial cells (iPSCs-ECs) and used to print large blood vessels with capillary beds in between.

The survival and function of tissues depend on appropriate vascularization. Blood vessels of the tissues supply oxygen, and nutrients and remove waste and byproducts. Incorporating blood vessels into engineered tissues is essential for overcoming diffusion limitations, improving tissue function, and thus facilitating the fabrication of thick tissues. Here, we present a modified ECM bioink, with enhanced mechanical properties and endothelial cell-specific adhesion motifs, to serve as a building material for 3D printing of a multiscale blood vessel network. The bioink is composed of natural ECM and alginate conjugated with a laminin adhesion molecule motif (YIGSR). The hybrid hydrogel was characterized for its mechanical properties, biochemical content, and ability to interact with endothelial cells. The pristine and modified hydrogels were mixed with induced pluripotent stem cells derived endothelial cells (iPSCs-ECs) and used to print large blood vessels with capillary beds in between.

Multiple catalytic oxidation processes involving new synthesized materials have recently been examined to replace conventional oxidative treatment methods for water purification, but upscaling and demonstration stages are mostly lacking, which hinders their practical implementation. In this study, we introduce a novel catalytic process where peroxymonosulfate (PMS) is activated by MnO2 surfaces that are attached on natural sand as part of a catalytic filtration column (CFC). PMS decomposition in the CFC was stable during steady-state filter operation with different natural waters (tap water and secondary effluent) and sulfate radicals were identified as main radical species. Complete oxidation (>99 %) of 10 mg/L rhodamine B in tap water could be achieved with PMS concentrations as low as 0.2 mM and a residence time of less than 3 min. Furthermore, unselective oxidation of various recalcitrant and …

In article number 2302229, Tal Dvir and co-workers demonstrate a biocompatible method for reinforcing engineered tissue post-fabrication. The technique enables 3D bioprinting of soft tissue and gives the cells time to establish intercellular communications before the tissue's mechanical properties are significantly improved by the reinforcement protocol. In the work, thick, vascularized cardiac tissues are enhanced to the point of injectability.

Constantly raising microplastic (MP) contamination of water sources poses a direct threat to the gentle balance of the marine environment. This study focuses on a multifactor hazard evaluation of conventional (polyethylene - PE, polypropylene - PP, and polystyrene - PS) and alternative (polyethylene terephthalate with 25 % or 50 % recycled material and polylactic acid) plastics. The risk assessment framework explored included MP abundance, water acidification potential, surface oxidation, fragmentation, and bacterial growth inhibition. Based on MP monitoring campaigns worldwide, we conclude that PE-based plastics are the most abundant MPs in water samples (comprise up to 82 % the MP in those samples). A year-long weathering experiment showed that PS-based and PP-based plastics were oxidized to a higher extent, resulting in the highest water acidification with pH reduction of up to three orders of …

Nonlinear photonic crystals (NPCs) with spatially modulated second‐order nonlinear coefficients are indispensable in nonlinear optics and modern photonics. To access full degrees of freedom in the generation and control of coherent light at new frequencies, three dimensional (3D) NPCs have been recently fabricated employing the femtosecond laser writing technique in ferroelectric crystals. However, the nonlinear interaction efficiencies in 3D NPCs so far are rather low, which has been a major barrier to further development. Here, fabrication challenges of large‐scale 3D NPCs have been overcome to realize more than four orders of magnitude efficiency improvement over previously reported crystals. With the generation of second harmonic vortex beam as an example, the measured conversion efficiencies as high as 2.9 × 10−6 W−1 (femtosecond pulse‐pumped) and 1.2 × 10−5 W−1 (continuous‐wave …

Multimode bright squeezed vacuum is a non-classical state of light hosting a macroscopic photon number while offering promising capacity for encoding quantum information in its spectral degree of freedom. Here, we employ an accurate model for parametric down-conversion in the high-gain regime and use nonlinear holography to design quantum correlations of bright squeezed vacuum in the frequency domain. We propose the design of quantum correlations over two-dimensional lattice geometries that are all-optically controlled, paving the way toward continuous-variable cluster state generation on an ultrafast timescale. Specifically, we investigate the generation of a square cluster state in the frequency domain and calculate its covariance matrix and the quantum nullifier uncertainties, that exhibit squeezing below the vacuum noise level.