Logic Gate Devices Research Articles

Optical Signal Modulation in Photonic Waveguiding Heteroarchitectures with Continuously Variable Visible‐To‐Near‐Infrared Emission Color (Adv. Mater. 45/2022)

Photonic Logic Gates In article number 2204839, Chi-Ming Che and co-workers describe a photonic logic gate device based on supramolecular heterostructures made by phosphorescent Au, Cu, Pt, and Pd complexes. The photonic logic gate operation is realized by an optical waveguiding effect and energy transfer among the different building blocks. These photonic logic gates have high emission anisotropy, low optical waveguiding loss, and continuously varied emission colors ranging from blue to near-infrared spectral regions.

Interaction between double solitons in anti-PT symmetric synthetic photonic lattices

An anti-parity-time symmetry (anti-PT symmetric) double fiber loop synthetic photonic lattice is constructed theoretically by projecting the intensity of two loops and adjusting the phase and gain/loss distribution. Numerical studies on pulse dynamics show that the trajectories of double-pulse solitons may be manipulated by tuning the initial relative phases, pulse separation, nonlinearity, and non-Hermitian characteristics of the system. Our research may provide a new way to realize logic gate devices and optical switches in optical interconnection and optical communications.

Design of an all-optical multi-logic operation-integrated metamaterial-based terahertz logic gate.

Terahertz logic gates play a vital role in optical signal processing and terahertz digitization. Herein, a strategy to design an all-optical terahertz logic gate device composed of metamaterials with a semiconductor-metal hybrid is proposed; accordingly, a concrete logic gate composed of Ge embedded-in Au stripe supported by a Si board is presented theoretically. Simulation results reveal the dependence of the terahertz transmission spectra on the different illuminations in the device. Based on the illumination-transmission response, the designed device can realize the NOR or OR Boolean operation. The effects of the width of the Ge-Au stripe as well as the Si board on the transmission spectra and logic performance were also investigated.

Multifunctional and wavelength division multiplexing all-optical logic gates based on four-port metal-insulator-metal waveguides coupled with a ring resonator.

In the past few years, designing multifunctional all-optical logic devices has attracted more and more attention in integrated optical computing. We report a metal-insulator-metal based four-port all-optical logic gate device containing two parallel straight waveguides and a ring resonator. We employ the scattering matrix method to analyze the coupling mechanisms of the hybrid waveguide and adopt the finite-difference time-domain method to design four fundamental logic functions of AND, OR, XOR, and NOT based on the all-optical coherent control of the four-port system under three symmetrically incident conditions. We demonstrate that these logic functions can be freely modulated by changing the phase difference of the input light at two resonant wavelengths or in a broad band. The logic gate device proposed shows a simple structure with multiple functions, multiple channels, and convenience in fabrication, and can be applied in parallel optical computing based on wavelength division multiplexing technology.

Exploring Axial Organic Multiblock Heterostructure Nanowires: Advances in Molecular Design, Synthesis, and Functional Applications

AbstractOrganic multiblock heterostructure nanowires (OMHNs), integrating distinct components in the same axial structure, have attracted much attention due to their excellent properties such as intrinsic good light confinement and rectification characteristics. However, rationally incorporating such features into OMHNs with rigorous 1D morphology control remains a key synthetic objective. It is because that the single components possess fundamentally distinctive properties such as size‐dependent electronic, optical, and magnetic features as well as lattice parameters. In the last decade, researchers made their own efforts to this exciting field, especially from the controlled fabrication to the advanced applications of the multiblock nanowires. As a result, various OMHNs have been developed as very promising candidates for high‐performance optoelectronic applications such as light harvesting, logic gate devices, photonic transistors, and photonic anticounterfeiting. Herein, the recent advances of OMHNs from the aspects of molecular design, synthesis, and advanced applications are reviewed, and an outlook is given providing inspiration for the future development of OMHNs toward integrated optoelectronic at nanoscale.

Fluorescein-2-(Pyridin-2-Ylmethoxy) Benzaldehyde Conjugate for Fluorogenic Turn-On Recognition of Hg2+ in Water and Living Cells with Logic Gate and Memory Device Applications

Fluorescein-2-(Pyridin-2-Ylmethoxy) Benzaldehyde Conjugate for Fluorogenic Turn-On Recognition of Hg2+ in Water and Living Cells with Logic Gate and Memory Device Applications

Periodic structure containing host hyperbolic material for nano-guiding, sensing and imaging applications

In this simulation work, we have theoretically proposed a design of hyperbolic material-based ternary multilayer structure of plasma photonic crystal comprised of dielectrics and plasma materials. The optical properties have been analyzed with the help of transfer matrix method (TMM). The obtained spectra of reflection, transmission and absorption drawn with variation in filling fraction for the hyperbolic meta-material-based PC, are analyzed. By varying the filling fraction as f=0.1,0.2,0.3,0.4, it is found that at normalized frequency range, above 0.2, reflection is negligible. Thereafter, in higher normalized frequency, there exist a bandgap in a normalized frequency range 0.82–1.35. From the transmission spectra, it is noted that the transmission is nearly zero in lower normalized frequency range 0.0–0.2, then the transmission increases, and further decreases with formation of a bandgap. On the other-hand, the absorption is nearly 90% at lower normalized frequency region; and at higher normalized frequency, a zero-absorption band is obtained. Thus, we obtain an enlarged PBG in the normalized frequency range 0.82 to 1.35, where the zero-absorptionband for normal incidence also occurs at low frequency. The absorption increases with an increase in the filling fraction. All these results are in a good agreement with those reported earlier by the researchers. The insights of the present article can be employed in design of tunable optical filter, optical window, optical logic gate, broadband reflector, and absorption-based devices. The article can also be useful in the investigations on nano-guiding, sensing and imaging applications.

Dual-Channel Probe of Carbon Dots Cooperating with Lanthanide Complex Employed for Simultaneously Distinguishing and Sequentially Detecting Tetracycline and Oxytetracycline.

Tetracycline (TC) and oxytetracycline (OTC) are the most widely used broad-spectrum antimicrobial agents in tetracycline drugs, and their structures and properties are very similar, so it is a great challenge to distinguish and detect these two antibiotics with a single probe at the same time. Herein, a dual-channel fluorescence probe (SiCDs@mMIPs-cit-Eu) was developed by integrating two independent reaction sites with SiCDs-doped mesoporous silica molecular imprinting group and europium complex group into a nanomaterial. The synergistic influence of inner filter effect and “antenna effect” can be guaranteed to solve the distinction between TC and OTC. Moreover, this novel strategy can also sequentially detect TC and OTC in buffer solution and real samples with high sensitivity and selectivity. This method revealed good responses to TC and OTC ranging from 0 to 5.5 μM with a detection limit of 5 and 16 nM, respectively. Combined with the smartphone color-scanning application, the portable and cheap paper-based sensor was designed to realize the multi-color visual on-site detection of TC and OTC. In addition, the logic gate device was constructed according to the fluorescence color change of the probe for TC and OTC, which provided the application possibility for the intelligent detection of the probe.

Optical-switched proton logic gate: Indocyanine green decorated HSB-W5 MOFs nanosheets

Proton conduction controlled by light is important for advanced applications in sensors and information processing devices. We herein report a metal-organic framework (MOF) thin film by introducing indocyanine green dye into HSB-W5 (HSB = hydrogenated Schiff base) matrix (ICG@HSB-W5) to construct a series of basic logic gates (NOT, NAND, and NOR) on account of its good photothermal conversion ability and photo-controlled proton conductivity. The proton conductivity of ICG@HSB-W5 thin film is 25 times higher than that of the pristine HSB-W5 thin film and responses efficiently to lasers. In addition, the change of proton conductivity is very large with an ON/OFF ratio above 1000 and enough to be distinguished to build logic gates. In this logic gate system, 808- and 405-nm lasers are used as inputs and the proton conductivity is used as output signal with different thresholds. The electrical output signal is convenient and available to be received and detected. It offers a new route for the design of molecular logic gates based on MOF and facilitates the construction of proton-based logic gate or more complicated logic devices.

Logic devices based on nucleic acid self‐assembly

AbstractNucleic acids are natural macromolecules with the ability to store and transmit information based on the strict base‐pairing principle. Beyond the natural nucleic acid double helixes, various DNA/RNA nanostructures with customized geometries and functionalities have been fabricated. Featured with programmability and sequence‐dependent responsiveness, DNA/RNA nanostructures have been employed for the rational design and construction of logic devices. When stimulated by internal molecular triggers and/or external stimuli, these logic gate devices can operate at nanoscale level in complex biological environments, performing logic operations and producing corresponding outputs. In this minireview, we summarize the recent advances of nucleic acid logic devices, which are responsive to various stimuli, including DNA/RNA strands, metal ions, small molecules, peptides, proteins, photo‐irradiation, pH changes, and so forth. The applications of these devices in biosensing and biofunction regulation are also included. In the last part of the present study, we discuss the remaining challenges and perspectives of nucleic acid logic devices.image

Fluorescence and scattering based dual-optical signals ratiometric sensing and logic gate device for acetylcholinesterase activity assay

Acetylcholinesterase (AChE) plays a crucial role in regulating the levels of the neurotransmitters in organisms. In this study, a dual-optical signals ratiometric sensing system based on fluorescence and scattered light was constructed by using silicon quantum dots (SiQDs) and MnO2 nanosheets for AChE activity assay. The two independent signals of fluorescence and scattering can be collected at the same excitation wavelength, which not only improves the accuracy of detection but also greatly simplifies the experimental operation. In this study, the SiQDs with excellent optical properties were successfully prepared by one-step hydrothermal method and the optimal emission peak was located at 445 nm. The fluorescence signal of SiQDs could be suppressed via MnO2 nanosheets on account of the inner filter effect (IFE). In addition, MnO2 nanosheets could provide a size-regulated second-order scattering (SOS) signal at 725 nm. Therefore, MnO2 nanosheets could play the dual roles of fluorescence signal quencher and SOS signal donor. AChE could act on the substrate acetylthiocholine (ATCh) and make it to engender thiocholine (TCh), which will triggered the reduction of MnO2 nanosheets, resulting the decompostion of MnO2 nanosheets. At the same time, the fluorescence of SiQDs recovery and the SOS signal decline. Thus, the ratiometric sensing analysis of AChE activity was achieved according to the opposite responses of fluorescence and scattering dual signals. Under the optimal conditions, an excellent linearity for AChE from 0.5 to 80.0 U/L and high sensitivity with a detection limit of 0.16 U/L were achieved. The practical application of the established method was assessed and verified by analyzing of AChE activity in human serum, and obtained satisfactory results. The proposed dual-optical signals ratiometric analytical strategy exhibits the merits of simple operation, high sensitivity and excellent selectivity, indicating that it has great application potential in diagnosis the AChE-related diseases. Furthermore, an innovative logic gate device was designed based on dual-optical signals, which has great value for the development of artificial intelligence analysis equipment to monitor AChE activity.

Acetate ion augmented fluorescence sensing of Zn2+ by Salen-based probe, AIE character, and application for picric acid detection.

Counter anion-triggered metal ion detection has been rarely reported by fluorimetric method. To address this challenging issue, a fluorescent probe (H2L) has been synthesized from bromo-salicylaldehyde and hydrazine hydrate, and structurally characterized by single crystal X-ray diffraction. The probe shows very weak fluorescence itself. However, its emission intensity increases in the presence of Zn2+ over other metal ions. Surprisingly, the emission profile of this probe in presence of Zn2+ is augmented only when acetate anion (OAc¯) is present as counter anion, that allows for precise quantitative analysis by spectroscopic studies. The compositions and complexation among the probe, Zn2+ ion, and OAc¯ are supported by ESI-MS, 1H-NMR, and Job's plot. Based on these studies, it is confirmed that the binding ratio between probe: metal is 1:2 and the detection limit (LOD) for the Zn2+ is 2.18 µM. The probe is capable of recognizing Zn2+ ion in the wide range of pH∼6.5-9.5, and it could be efficiently recycled by EDTA. Furthermore, the combinatorial molecular logic gate and memory device have been constructed from the fluorescent behavior of H2L with Zn2+, OAc¯, and EDTA input as based on NOT and AND gates. Interestingly, the aggregation-induced emission (AIEE) phenomenon is also perceived with greater than 50% water content in organic water mixtures, which are then useful for the detection of picric acid often used as explosive.

Smartphone-based ratiometric fluorescent definable system for phosphate by merged metal−organic frameworks

Phosphate plays an important role in a wide range of chemical and biological processes, so the development of a new phosphate optical sensor with high sensitivity, specificity and visual recognition function has important practical significance. Herein, a ratiometric fluorescent (RF) probe and a smartphone-integrated colorimetric test paper sensing platform for assay phosphate was fabricated using hybrid fluorescent UiO-66-NH2 and Eu3+@MOF-808 metal−organic frameworks. After continuous addition of phosphate, the blue fluorescence emission of UiO-66-NH2 and the red emission of Eu3+@MOF-808 were regularly enhanced and quenched respectively, and the fluorescence response of the detection platform to phosphate exhibited a clear color change process (red → pink → blue). More importantly, the probe solution and test paper of the integrated smartphone are converted to digital values through RGB channels and successfully used to visualize semi-quantitative recognition of phosphate. In addition, an RF probe and a smartphone integrated fluorescent test paper were developed separately to devise logic gate devices for detecting phosphate. The multifunctional ratio sensing platform integrated by the smartphone furnishes a new strategy and broad prospects for the intelligent online identification of important targets in biological samples and environmental samples.

WITHDRAWN: Exploring Bahaviors of Electrode-driven Si Quantum Dot Systems: From Charge Control to Qubit Operation

Abstract Charge stabilities and spin-based quantum bit (qubit) operations in Si double quantum dot (DQD) systems, whose confinement potentials are controlled with multiple gate electrodes, are theoretically studied with a multi-scale modeling approach that combines electronic structure simulations and a Thomas-Fermi method. Taking Si / SiGe heterostructures as the target of modeling, this work presents in-depth discussion on designs of electron reservoirs, electrostatic controls of quantum dot (QD) shapes and corresponding charge confinement, and spin qubit manipulations. Effects of unintentional inaccuracy in DC control biases and geometric symmetries on the Rabi cycle of spin qubits are investigated to examine the robustness of logic operations. Solid connections to the latest experimental result are also established to validate the simulation method. As a rare modeling study that explores a full-stack functionality of Si DQD structures as quantum logic gate devices, this work delivers the knowledge of engineering details that are not uncovered by the latest experimental work, and can serve as a basic but practical guideline for potential device designs.

Fluorenyl-difluoroboron-β-diketonates with multi-stimuli fluorescent response behavior and their applications in a thermochromic logic gate device

Materials exhibiting multi-stimuli responsive luminescence are useful for applications in information encryption, fluorescence sensors, and optoelectronic devices. Herein, we report the development of fluorenyl-difluoroboron-β-diketonates that provide multi-stimuli responsive fluorescence. These complexes exhibit weak fluorescence in a diluted solution and aggregation-induced emission in the solid state. The solid-state emission color of these complexes can be tuned by grinding-fuming and grinding-heating cycles. Our experimental data reveal that propeller-shaped donor-acceptor structure and loose molecular packing structure induced by long alkyl chains are the key factors related to the stimuli response sensitivity. Furthermore, we demonstrate the information-process applications of these materials for use in a thermochromic logic gate device.

A Single‐Molecule and Logic Gate via Optical and Acid–Base Control

AbstractSingle‐molecule electronics is a promising solution for electronic device miniaturization. While controllable molecular logic gates are particularly attractive because they are the primary element and can accomplish logical operation reliable and repeatedly for practical application. Here, a brand‐new molecule, which is constructed from a light‐switchable azobenzene unit and proton‐switchable pyrimidine unit, is reported. The electronic transport properties of the molecule are theoretically investigated by density functional theory (DFT) combined with non‐equilibrium Green's function method (NEGF). The calculated current–voltage curves show that the molecule system produces a low resistance only when the ultraviolet (UV) light and acid solution are applied, otherwise, a high resistance will be obtained. Therefore, the molecule system can behave as a single‐molecule AND logic gate which can be controlled by two orthogonal inputs: protonation and light. This work demonstrates a feasible perspective for creating single‐molecule logic gate device.

Resistance characteristics analysis of droplet logic gate based on lattice Boltzmann method

In this paper, the geometric models of microfluidics NON-AND and AND-OR droplet logic gate devices are designed, and the operations of NON-AND and AND-OR logic are implemented in the designed models. Based on the color-gradient model (R-K model) of lattice Boltzmann method (LBM), the two-phase flow pattern in microchannel is simulated. Based on the “equivalent length method”, the Laplace resistance at the droplet phase interface and the local resistance at the right-angle bend are equivalent to the additional pipe length required for continuous phase flow in the channel to generate the same on-way resistance increment, and the resistance characteristics when slug flow droplets exist in the microchannel are quantitatively analyzed. The method is further applied to the analysis of the resistance characteristics of the droplet logic gate, and the quantitative explanation of the droplet path-choosing behavior is obtained. Compared with the “hydroelectricity analogism method”, the “equivalent length method” is more concise and easy to understand. The research results in this paper provide theoretical basis for the design of other forms of droplet logic gate devices.

Eu3+@metal–organic frameworks encapsulating carbon dots as ratiometric fluorescent probes for rapid recognition of anthrax spore biomarker

Anthrax spores pose a serious threat to human well-being and life, so it is highly desirable to develop a rapid, sensitive, and selective quantitative assay of calcium pyridine dicarboxylate (CaDPA) as a biomarker of anthrax spores. Herein, carbon dots (CDs) chelated Eu3+@metal–organic framework (Eu-MOFs) as dual-emissive ratiometric fluorescent (RF) probe was successfully fabricated by a simple one-pot in situ selective self-assembly synthetic strategy. The developed RF probe has an effective self-calibration function, which performs a highly sensitive and selective recognition of CaDPA in water and human serum sample. The blue-emitting CDs was employed as an effective fluorescence reference, while the Eu-MOFs exhibited enhanced red fluorescence signal through the coordination interaction with CaDPA chromophore. The sensing mechanism is attributed to that CaDPA can sensitize Eu3+ intrinsic luminescence due to the energy transfer from CaDPA to Eu3+. What's more interesting is that with the continuous drop of CaDPA, the emission color of CDs@Eu-MOF changes from blue to red. The results revealed that CDs@Eu-MOFs RF probe can detect CaDPA effectively in the range of 8–170 μg/L with good linear relationship, and exhibited a remarkable selectivity for CaDPA. More interestingly, a paper-based probe has also been devised for on-site detection of CaDPA. In addition, CaDPA is used as input signal to construct an IHIBITION logic gate device which performs the “off-on” mode. The constructed CDs@Eu-MOF probe can achieve exceptionally rapid, highly sensitive and selective detection of CaDPA, which can further expand the application prospects in environmental and biological analysis.

1,3,4-Oxadiazole based ruthenium amphiphile for Langmuir-Blodgett films and photo-responsive logic gate construction

Amphiphilic ruthenium bipyridine complexes based on 1,3,4-oxadiazole-pyridine ligands (L1, L2) were synthesized and characterized by 1H NMR, UV–Vis spectroscopy, electrochemistry and UV–Vis spectroelectrochemistry. The free ligands and the respective ruthenium(II) complexes exhibit an intraligand π−π∗ absorption band in the UV region that overlaps with the MLCT bands. The [Ru(bpy)2(L2)](PF6)2 complex with a bidentated L2 ligand did not form a stable monolayer in water-air interface demonstrating the relevance of coordination geometry on the molecular packing properties. In contrast, stable Langmuir-Blodgett films of the [Ru(bpy)2(L1)Cl]PF6 complex (RuL1) exhibiting reversible and fast spectroelectrochemical properties associated with the Ru(III/II) redox couple were obtained, where redox site inactivation become relevant above 20 monolayers where the current leveled up. Thin LB films were deposited on poly(bithiophene) to enhance its photoelectrochemical properties and realize photoresponsive AND and OR logic gate devices.

Thermal rectification of graphene on substrates with inhomogeneous stiffness

Thermal rectification is of great importance in various thermal management and thermal logic applications, where heat flux runs preferentially in one direction over the opposite one. This phenomenon is mostly reported in previous simulations and experiments by introducing asymmetry shape-tailoring, defects and doping, etc. However, these approaches break the structure of the heat conductor. In this paper, we report thermal rectification induced by modulating the substrate stiffness on the supported graphene, which preserves structural integrity of graphene, making it reusable. Our results show that the heat flux prefers to flow toward the stiffer part of a substrate. The maximum thermal rectification factor can reach ∼48% by using the ideal substrate model prediction. Moreover, a wide range thermal rectification factor of 3.5%–22.7% can be achieved by using a sandwich model. These phenomena are explained by phonon vibration spectra and excitation simulations. Our results should be of great help for understanding the modulation of thermal rectification in supported material and shed light on the design of a new thermal logic gate and thermal management devices.