Rewritable Data Research Articles

Fully Optical Control of Polarization Current Direction in a Cyanide‐Bridged Trinuclear Complex

AbstractAs a remote and non‐contact stimulus, light offers the potential for manipulating the polarization of ferroelectric materials without physical contact. However, in current research, the non‐contact write‐read (erase) process lacks direct observation through the stable current as output signal. To address this limitation, we investigated the photoinduced polarization switching capabilities of the cyanide‐bridged compound [Fe2Co] using visible light, leading to the achievement of rewritable polarization. By subjecting [Fe2Co] crystals to alternating irradiation with 785 nm and 532 nm light, the polarization changes exhibited a distinct square wave pattern, confirming the reliability of the writing and erasing processes. Initialization involved exposing specific crystal units to 532 nm light for storing “1” or “0” information, while reading was accomplished by scanning the units with 785 nm light, resulting in brief current pulses for “1” states and no current signal for “0” states. This research unveils new possibilities for optical storage systems, paving the way for efficient and rewritable data storage and retrieval technologies, such as the next‐generation memories.

Fully Optical Control of Polarization Current Direction in a Cyanide-Bridged Trinuclear Complex.

As a remote and non-contact stimulus, light offers the potential for manipulating the polarization of ferroelectric materials without physical contact. However, in current research, the non-contact write-read (erase) process lacks direct observation through the stable current as output signal. To address this limitation, we investigated the photoinduced polarization switching capabilities of the cyanide-bridged compound [Fe2Co] using visible light, leading to the achievement of rewritable polarization. By subjecting [Fe2Co] crystals to alternating irradiation with 785 nm and 532 nm light, the polarization changes exhibited a distinct square wave pattern, confirming the reliability of the writing and erasing processes. Initialization involved exposing specific crystal units to 532 nm light for storing "1" or "0" information, while reading was accomplished by scanning the units with 785 nm light, resulting in brief current pulses for "1" states and no current signal for "0" states. This research unveils new possibilities for optical storage systems, paving the way for efficient and rewritable data storage and retrieval technologies, such as the next-generation memories.

Multidimensional Data Encoding Based on Multicolor Microencapsulated Thermoresponsive Fluorescent Phase Change Materials

AbstractLuminescent materials are emerging promising tools for digital data encoding due to their reduced cost, facile reading, robustness, and durability. For this, the use of fluorescent systems that combine multicolor emission with sensitivity to external stimuli will be highly desirable, as they can offer rewritable data encoding together with enhanced encryption security and storage density. Herein a novel strategy is pioneered to reach this goal, which exploits the temperature‐responsive emission properties of the mixtures of regular fluorophores with simple organic phase change materials (PCMs) such as paraffins. By preparing a diversity of microcapsules of these mixtures comprising different dyes and PCMs, thermosensitive fluorescent pixels can be prepared in a low‐cost, straightforward, and scalable manner that exhibits multicolor dynamic emission behavior. These features are capitalized to fabricate pixel arrays that perform two advanced digital encoding operations: high‐security 3D information encryption, and 4D data storage.

Investigating the Polarity Dependence of Multilevel Cell Operation in Conventional Mushroom Phase‐Change Memory Cells

Phase‐change materials have long been employed for rewriteable optical data storage at the industrial scale and are hailed as one of the most mature technologies for their applications in emerging nonvolatile memories. Memristors based on these materials have the potential to circumvent the long‐standing von Neumann bottleneck and offer significant computational advantage through neuromorphic computing. A very core fundamental concept that lies at the crux for such realization is their ability to offer multilevel cell (MLC) storage, in contrast to the binary counterpart. Yet, numerous challenges still remain to be tackled for their successful implementation in this regard. This work is a finite element analysis that particularly reports the polarity dependence of such MLC operation in the conventional mushroom geometry of devices employing this technology. The mechanism lying underneath is discussed and a perspective combining thermoelectric effects with the energy band diagrams resulting from metal–semiconductor contact formation is additionally put forth.

Enhanced up-conversion persistent luminescence of Zn2GeO4:Mn phosphors by non-equivalent doping and sensitization of up-conversion nanocrystals

Up-conversion persistent luminescence (UCPL) nanoparticles have captured tremendous attention due to their unique optical operating performance such as the absence of auto-fluorescence and the charging capacity of near-infrared (NIR) light. However, the weak afterglow intensity as well as low duration limits their practical applications including multimode anti-counterfeiting and biological imaging, etc. Herein, typical green persistent luminescence (PersL) and photo-stimulated luminescence (PSL) of Zn2GeO4:Mn2+ phosphors were enhanced via non-equivalent Li+ co-doping, in which the preferred site selection of Mn2+ and Li + have been verified by using the first-principles theory. The possible luminescent enhancement mechanisms were proposed based on improving the oxygen vacancy density and promoting the formation of Mn4+ defect energy level in bandgap structure by non-equivalent doping of Li+. Interestingly, UCPL of Zn2GeO4:Mn2+,Li + can be achieved after charging of Vis to NIR light. It is worth noting that this UCPL can be further enhanced by the sensitization of NaYF4:Yb,Tm nanoparticles via simply mixing Zn2GeO4:Mn2+,Li+ and NaYF4:Yb,Tm under 980 laser stimulation. As a result, Zn2GeO4:Mn2+,Li+ phosphor exhibits the enhanced quintuple-mode luminescence including photoluminescence, PersL, PSL, photo-stimulated persistent luminescence and UCPL. In particular, the achieved NIR rechargeable UCPL hybrid phosphors exhibit enormous potential for higher order anti-counterfeiting and rewriteable data encryption and decryption applications.

Multicolor emissive organic material to display aggregation caused red shift with dual state emission, and application towards rewritable data storage

The development of dual-state organic luminogens with high emission efficiency both in solution and solid phase is still a difficult task. Dual-state emissive fluorescent materials have proven to have a much broader application in several fields. Molecular design plays a significant role in fabricating switchable as well as tunable emissions. Nonetheless, the mechanism of dual-state emission needs to be studied further. Herein, two compounds, Blue-Yellow emissive material (BYEM) and Green-Red emissive material (GREM), have been designed and synthesized for a novel class of luminogens with dual-state emission (DSEgens) properties. These compounds emit luminously in solution state as well as solid state, with Aggregation Caused Red-Shifted Emission (ACRE) emission. Close-packed molecular structure and the steric hindrance effect can reduce the intramolecular rotation solution state, which accelerates the radiative transition of the compound in the solution state. On the contrary, in the solid state, the twisted structure and intermolecular C–H⋯π interactions can indorse the J-aggregation, which leads to the high fluorescence at the solid state. Significant red shift emission at solid state has been supported by theoretical calculations. On the other hand, by combining a partly shared donor–acceptor unit based on the twisted molecule, these compounds have shown good solvatochromic behavior. Gradual redshift emission has been observed as the solvent polarity is increased. These dual state highly emissive compounds can be applied in several industrial applications as well as the biomedical field.

Mechanoluminescent property of bis(phenylethynyl)platinum(II) complexes bearing substituted bipyridine and their application for developing rewritable data recording device

Two platinum(II) complexes, Pt(DiClBpy)(CCC6H5)2 (1) and Pt(DiBrBpy)(CCC6H5)2 (2) based on 4,4′-dichloro-2,2′-bipyridine (DiClbpy), 4,4′-dibromo-2,2′-bipyridine (DiBrbpy) and phenylacetylene ligands were synthesized and characterized. Both complexes display reversible and reproducible mechanochromic and mechanoluminescent properties with the luminescence red-shift exceeding 150 nm. Systematic studies on crystal structure, luminescence spectra, and PXRD demonstrate that the mechanochromic and mechanoluminescent properties of 1 and 2 are attributed to the formation/elimination of intermolecular Pt-Pt interactions during mechanical grinding/vapor absorption process, which lead to the transformation of the lowest energy excited states between MLCT and MMLCT transitions. In addition, based on such property, 1 and 2 were used as starting functional material to successfully develop the rewritable data recording device.

Understanding AIE and ACQ phenomenon of organometallic iridium(III) complexes by simple cationization engineering

Understanding the relationship between structure and properties is critical to the development of solid-state luminescence materials with desired characteristics and performance optimization. In this work, we elaborately designed and synthesized a pair of mononuclear iridium(III) complexes with similar structures but different degrees of cationization. [Ir2-f][2PF6] with two counterions is obtained by simple N-methylation of the ancillary ligand of [Ir1-f][PF6] which is a classic cationic iridium(III) complex. Such a tiny modification results in tremendously different optical properties in dilute solutions and powders. [Ir1-f][PF6] exhibits weak light in solution but enhanced emission in solid-state as well as poly(methyl methacrylate) matrix, indicative of its aggregation-induced emission (AIE) activity. On the sharp contrary, [Ir2-f][2PF6] is an aggregation-caused quenching (ACQ) emitter showing strong emission in the isolated state but nearly nonemissive in aggregation states. Benefiting from the appealing characteristics of mechanochromic luminescence and AIE behavior, [Ir1-f][PF6] has been successfully applied in reversible re-writable data recording and cell imaging. These results might provide deep insights into AIE and ACQ phenomenon of iridium(III) complexes and facilitate the development of phosphorescent materials with promising properties.

Data Mining with Privacy Protection Using Precise Elliptical Curve Cryptography

Protecting the privacy of data in the multi-cloud is a crucial task. Data mining is a technique that protects the privacy of individual data while mining those data. The most significant task entails obtaining data from numerous remote databases. Mining algorithms can obtain sensitive information once the data is in the data warehouse. Many traditional algorithms/techniques promise to provide safe data transfer, storing, and retrieving over the cloud platform. These strategies are primarily concerned with protecting the privacy of user data. This study aims to present data mining with privacy protection (DMPP) using precise elliptic curve cryptography (PECC), which builds upon that algebraic elliptic curve in finite fields. This approach enables safe data exchange by utilizing a reliable data consolidation approach entirely reliant on rewritable data concealing techniques. Also, it outperforms data mining in terms of solid privacy procedures while maintaining the quality of the data. Average approximation error, computational cost, anonymizing time, and data loss are considered performance measures. The suggested approach is practical and applicable in real-world situations according to the experimental findings.

Designing Glass and Crystalline Phases of Metal-Bis(acetamide) Networks to Promote High Optical Contrast.

Owing to their high tunability and predictable structures, metal-organic materials offer a powerful platform to study glass formation and crystallization processes and to design glasses with unique properties. Here, we report a novel series of glass-forming metal-ethylenebis(acetamide) networks that undergo reversible glass and crystallization transitions below 200 °C. The glass-transition temperatures, crystallization kinetics, and glass stability of these materials are readily tunable, either by synthetic modification or by liquid-phase blending, to form binary glasses. Pair distribution function (PDF) analysis reveals extended structural correlations in both single and binary metal-bis(acetamide) glasses and highlights the important role of metal-metal correlations during structural evolution across glass-crystal transitions. Notably, the glass and crystalline phases of a Co-ethylenebis(acetamide) binary network feature a large reflectivity contrast ratio of 4.8 that results from changes in the local coordination environment around Co centers. These results provide new insights into glass-crystal transitions in metal-organic materials and have exciting implications for optical switching, rewritable data storage, and functional glass ceramics.

Rewritable two-dimensional DNA-based data storage with machine learning reconstruction

DNA-based data storage platforms traditionally encode information only in the nucleotide sequence of the molecule. Here we report on a two-dimensional molecular data storage system that records information in both the sequence and the backbone structure of DNA and performs nontrivial joint data encoding, decoding and processing. Our 2DDNA method efficiently stores images in synthetic DNA and embeds pertinent metadata as nicks in the DNA backbone. To avoid costly worst-case redundancy for correcting sequencing/rewriting errors and to mitigate issues associated with mismatched decoding parameters, we develop machine learning techniques for automatic discoloration detection and image inpainting. The 2DDNA platform is experimentally tested by reconstructing a library of images with undetectable or small visual degradation after readout processing, and by erasing and rewriting copyright metadata encoded in nicks. Our results demonstrate that DNA can serve both as a write-once and rewritable memory for heterogenous data and that data can be erased in a permanent, privacy-preserving manner. Moreover, the storage system can be made robust to degrading channel qualities while avoiding global error-correction redundancy.

Order-disorder structural transition in Pr3+-doped Ba3Ga2O6 for rewritable and write-once-read-many optical data storage

The emerging challenges of the big data era, both in storage density and security, require the development of the next-generation optical data storage materials. Here, we report for the first time a photo-stimulated luminescence (PSL) material, Ba3Ga2O6: Pr3+, for rewritable optical storage and write-once-read-many data preservation. Ba3Ga2O6: Pr3+, with an isolated deep trap depth in the range 1.26–1.53eV, has been used for data encoding/decoding under the excitation of 254 nm UV light and by the simulation of an 808 nm NIR laser. Meanwhile, the phosphor allows for high-security write-once-read-many optical memory by taking advantage of the irreversible change of the photoluminescence (PL) color from blue to green (a binary blue ‘0’ and green ‘1’ code) irradiated by 365 nm UV light. The comprehensive investigations indicate that the irreversible PL switching is as a result of the order-disorder structural transition by thermal treatment. The new persistent luminescence material not only exhibits promising applications in sustainable rewritable data storage, but also paves the way for write-once-read-many optical information storage with a high level of security.

Rewritable Macromolecular Data Storage with Automated Read‐out

AbstractRewriting data stored on synthetic macromolecules is an interesting feature, even though it is considered as being quite challenging within the area of digital macromolecules. In this context, we initially studied a strategy for modifying the position tag of sequence‐encoded macromolecules in a reversible manner. The efficiency of this method, which relies on the orthogonal cleavage of a thioester moiety via aminolysis, was demonstrated by modifying parts of an exemplary sentence. Simultaneously, a novel algorithm was developed to ease the read‐out of macromolecular information by means of MS/MS techniques. This program, Oligoreader, can identify potential information‐containing macromolecules from a series of MS1 spectra, analyze the corresponding MS2 spectra, and finally decode the data. Consequently, the algorithm simplifies the entire read‐out process by avoiding any interference from the operator, which increases the potential for blind sequencing of uniform macromolecules.

Rewritable Macromolecular Data Storage with Automated Read-out.

Rewriting data stored on synthetic macromolecules is an interesting feature, even though it is considered as being quite challenging within the area of digital macromolecules. In this context, we initially studied a strategy for modifying the position tag of sequence-encoded macromolecules in a reversible manner. The efficiency of this method, which relies on the orthogonal cleavage of a thioester moiety via aminolysis, was demonstrated by modifying parts of an exemplary sentence. Simultaneously, a novel algorithm was developed to ease the read-out of macromolecular information by means of MS/MS techniques. This program, Oligoreader, can identify potential information-containing macromolecules from a series of MS1 spectra, analyze the corresponding MS2 spectra, and finally decode the data. Consequently, the algorithm simplifies the entire read-out process by avoiding any interference from the operator, which increases the potential for blind sequencing of uniform macromolecules.

The triple-stimuli-responsive luminescence switching properties and application of a square-planar platinum(II) complex

A new square-planar platinum (II) complex, Pt(Me3SiC≡CbpyC≡CSiMe3)(CCC6H4–Me-4)2 (1) was synthesized and characterized. This complex has a series of metastable structures, including seven orange solvated species, red 1·½(ClCH2CH2Cl), dark-brown 1B, black 1·¼(CH2Cl2) and 1·½(CH3OH), red-brown 1H and solvent-free amorphous 1G. Among them, 1B, 1H, 1G, 1·¼(CH2Cl2) and 1·½(CH3OH) display the long-wavelength NIR luminescence with emission beyond 900 nm. Complex 1 exhibits interesting triple-stimuli-responsive luminescence switching properties. First, 1 shows the reversible vapochromic and vapoluminescence properties between different metastable structures. Upon heating, all species of 1 change to a same solvent-free sample 1H, which emits the NIR luminescence peaked at 988 nm and can be reversibly converted back to the original species by exposure to specific VOC vapor. Furthermore, 1 also shows reversible mechanoluminescence property that all species of 1 will change to a brown amorphous 1G after grinding with its emission wavelength peaked at 954 nm. Systematic studies revealed that the vapor-, thermo-, and mechanical-grinding-triggered triple-stimuli-responsive luminescence switching property of 1 is due to the structural conversion and resultant changes of the lowest-energy excited states. Interestingly, the stacking structure and solvated molecule can influence the responses of metastable structures of 1 to heating or mechanical grinding. In addition, complex 1 can be used for visual recognition of CH3CN and 1,2-dichloroethane vapors as well as the development of simple rewritable data recording device.

Multimodal sensing in rewritable, data matrix azobenzene-based devices

Here, we exploited the UV light and thermal triggered E ↔ Z photoisomerization of an azobenzene compound to fabricate multimodal readable and rewritable data matrix based devices.

Improved Coefficient Recovery and Its Application for Rewritable Data Embedding.

JPEG is the most commonly utilized image coding standard for storage and transmission purposes. It achieves a good rate–distortion trade-off, and it has been adopted by many, if not all, handheld devices. However, often information loss occurs due to transmission error or damage to the storage device. To address this problem, various coefficient recovery methods have been proposed in the past, including a divide-and-conquer approach to speed up the recovery process. However, the segmentation technique considered in the existing method operates with the assumption of a bi-modal distribution for the pixel values, but most images do not satisfy this condition. Therefore, in this work, an adaptive method was employed to perform more accurate segmentation, so that the real potential of the previous coefficient recovery methods can be unleashed. In addition, an improved rewritable adaptive data embedding method is also proposed that exploits the recoverability of coefficients. Discrete cosine transformation (DCT) patches and blocks for data hiding are judiciously selected based on the predetermined precision to control the embedding capacity and image distortion. Our results suggest that the adaptive coefficient recovery method is able to improve on the conventional method up to 27% in terms of CPU time, and it also achieved better image quality with most considered images. Furthermore, the proposed rewritable data embedding method is able to embed 20,146 bits into an image of dimensions .

Fabrication of Ge<sub>30</sub>Te <sub>70-x</sub>Sb<sub>x</sub> Glasses Alloys and Studying the Effect of Partial Substitution on D.C Electrical Energy Parameters

The non-linear components has been emphasized for its multiple applications in rewritable recording and data storage devices. Chalcogenide glasses materials are promising due to their high refractive index. In this paper, alloys for Ge30Te70-xSbxglasses semiconductor (where x =0.0, 5, 10, 15 and 20) will be fabricated by melt quenching method. The effect of partial substitution on DC electric power parameters, and its knowledge of electrical conduction mechanisms, were investigated to determine the effect of Antimony on the density of extended states, local states, and in Fermi energy states. The electrical measurements revealed the existence of three conduction mechanisms depend on the temperature: at high temperature the conduction will be in the extended state. The local states are responsible at medium temperature, and at low temperature it will related to the Fermi level. The effect of partial substitution had produced change in all electrical conductivity parameters including the (extended, localized, and Fermi) density of states, the activation energy, tail width (ΔE), hoping transition distance (R), and interatomic distances a.

The Thinnest Light Disk: Rewritable Data Storage and Encryption on WS2 Monolayers (Adv. Funct. Mater. 36/2021)

The Thinnest Light Disk: Rewritable Data Storage and Encryption on WS₂ Monolayers (Adv. Funct. Mater. 36/2021)

The Thinnest Light Disk: Rewritable Data Storage and Encryption on WS2 Monolayers

AbstractThe thinnest light disk is demonstrated at the atomic level by developing an erasable method to directly write encrypted information onto WS2 monolayers. The write‐in is realized by precise control of photoluminescence emission by means of ozone functionalization and scanning focused laser beam. The visual decryption and reading‐out of information are enabled by fluorescence contrast. The high encryption level is ensured by the threshold power upon which the data deletion will be triggered. Owing to the high spatial resolution and power sensitivity, the storage capacity within <1 nm thickness can be up to ≈62.5 MB cm−2, and the writing speed can reach ≈6.25 MB s−1. Density functional theory calculations suggest that the disk formatting is realized by ozone molecule adsorption induced localized unoccupied states, while the read‐in relies on the passivation of defects via substitution of the sulfur vacancies with oxygen atoms. The results of this study promote data storage and encryption on the atomic scale.