Chiral Matrix Research Articles

Chiral Twist Interface Modulation Enhances Thermoelectric Properties of Tellurium Crystal.

Manipulating the grain boundary and chiral structure of enantiomorphic inorganic thermoelectric materials facilitates a new degree of freedom for enhancing thermoelectric energy conversion. Chiral twist mechanisms evolve by the screw dislocation phenomenon in the nanostructures; however, contributions of such chiral transport have been neglected for bulk crystals. Tellurium (Te) has a chiral trigonal crystal structure, high band degeneracy, and lattice anharmonicity for high thermoelectric performance. Here, Sb-doped Te crystals are grown to minimize the severe grain boundary effects on carrier transport and investigate the interface of chiral Te matrix and embedded achiral Sb2Te3 precipitates, which induce unusual lattice twists. The low grain boundary scattering and conformational grain restructuring provide electrical-favorable semicoherent interfaces. This maintains high electrical conductivity leading to a twofold increase in power factor compared to polycrystal samples. The embedded Sb2Te3 precipitates concurrently enable moderate phonon scattering leading to a remarkable decrease in lattice thermal conductivity and a high dimensionless figure of merit(zT)of 1.1 at 623 K. The crystal growth and chiral atomic reorientation unravel the emerging benefits of interface engineering as a crucial contributor to effectively enhancing carrier transport and minimizing phonon propagation in thermoelectric materials.

Deviation probabilities for extremal eigenvalues of large Chiral non-Hermitian random matrices

Abstract Consider the chiral non-Hermitian random matrix ensemble with parameters n and v, and let ( ζ i ) 1 ≤ i ≤ n {(\zeta_{i})_{1\leq i\leq n}} be its n eigenvalues with positive x-coordinate. In this paper, we establish deviation probabilities and moderate deviation probabilities for the spectral radius ( n n + v ) 1 2 ⁢ max 1 ≤ i ≤ n ⁡ | ζ i | 2 {(\frac{n}{n+v})^{\frac{1}{2}}\max_{1\leq i\leq n}|\zeta_{i}|^{2}} , as well as ( n n + v ) 1 2 ⁢ min 1 ≤ i ≤ n ⁡ | ζ i | 2 {(\frac{n}{n+v})^{\frac{1}{2}}\min_{1\leq i\leq n}|\zeta_{i}|^{2}} .

High Internal Phase Emulsion for Constructing Chiral Helical Polymer-Based Circularly Polarized Luminescent Porous Materials.

Polymerized high internal phase emulsions (polyHIPEs) with circularly polarized luminescence (CPL), as an interesting class of porous materials, are of great significance for the development of CPL porous materials but have not been reported so far. Herein, we report the construction of polyHIPE-based CPL porous materials, taking advantage of an adsorption strategy. The pristine polyHIPEs constructed by chiral helical polymers, which acted as a chiral microenvironment, were fabricated by coordination polymerization of chiral acetylene monomers (R/S-SA) using HIPEs as templates. Achiral fluorescent small molecules were dispersed in the pores of the 3D porous organic chiral polymer matrix provided by polyHIPEs through the adsorption strategy, and CPL-active porous materials with blue, cyan, and green emissions were constructed using a fluorescence-selective absorption mechanism that does not rely on chirality transfer at the molecular level. The maximum luminescence dissymmetry factor (glum) value was -2.6 × 10-2. This work establishes a new and simple way for developing CPL porous materials.

Texture photograph of the year 2023

ABSTRACT The purpose of this study was to maximise circularly polarised luminescence (CPL) utilising chiral templating that manipulates the helical nature of bent-core liquid crystals (BCLC) concentrated with a high quantum-yield luminophore. Using a chiral template and an achiral phosphorescent and liquid crystal emitter that can allow chirality transfer, the resulting complex induces circular polarisation without aggregation-caused quenching events. This enables the integration of our luminophore into a chiral matrix at very high concentrations. Using this new, all-inclusive model in lab, we designed a polarised light source controlled through the helical-type morphology of the template giving access to a highly tunable CPL system with an excellent dissymmetry factor ( g lum ). This system can aid in many optical processes or thermal-rate indicators.

Circularly polarized luminescence and nonlinear optical harmonic generation based on chiral zinc halides.

Chiral hybrid metal halides have grabbed extensive attention in linear and nonlinear chiroptics. Herein, 0D chiral zinc halides, (R-/S-2-MP)ZnCl4, have been fabricated, which demonstrate high efficiency second-order nonlinear optical responses. Incorporating Sb3+ into the chiral zinc halide matrix triggers the circularly polarized luminescence effectively with a balance between quantum yield and luminescence dissymmetry factor.

Chiral fermions, dimensional regularization, and the trace anomaly

We investigate the trace anomaly of a chiral fermion in dimensional regularization, considering in detail the simplest case of coupling to an abelian gauge field. We apply the Breitenlohner-Maison/'t Hooft-Veltman prescription for dealing with the chiral matrix γ5 and verify that no parity-odd term arises in the trace anomaly. The issue treated here is analogous to that of a chiral fermion in curved spacetime, discussed in recent literature. The advantage of having a simplified background minimizes the amount of algebraic calculations and allows pinpointing better the subtle points carried by dimensional regularization.

Encryption, decryption, and control with fractional quantum bits, quantum chiral states and pyramidal quantum bits switching in graphene

A novel method for encryption, decryption, and control of data using the theory of “rings and fields” is proposed. A system comprising a ring or loop with a maximum of six vector tuples or sub-loops, which are changed into knots on a ring, is suggested, whereby these vector tuples at 0.4 ≤ nf ≤ 0.9 hold Dirac bosons. The Dirac bosons are precessed at characteristic frequencies and are integrated with a braid; the remaining fractional quantum bits (f-qubits) are occupied with Dirac fermions with the same braid, i.e., 0.1 ≤ nf ≤ 0.3. The fractional Fourier transform is used for modeling and simulating the eigenfunctions for stretching, twisting, and twigging. The fractional charges are quantized and invariant at knots, where subquanta—Dirac bosons—are held on the honeycomb lattice of graphene. The degeneracy of f-qubits is permanently established. The characteristic magnetic excitations due to different precessing frequencies of Dirac bosons are exploited for encryption and decryption. The spinning and precessing Dirac fermions are used for pyramidal switching. Addresses for f-qubits are evaluated by normalizing the Hamiltonian operator, which becomes Hermitian. The topological transitions for a quantized non-interacting electron as above are exploited. A method for encryption, decryption, and control of quantum information with seventy-two (72) “quantum chiral states” is suggested with graphene. The chiral matrix of nfxg2/ℏc, where 0.1 ≤ nf ≤ 0.9 and 0.02 ≤ g2/ℏc ≤ 0.08, is the most suitable option for f-qubits as compared to qubits especially when conformal mapping for quantum computation is accomplished.

Circularly Polarized Light Source from Self‐Assembled Hybrid Nanoarchitecture

AbstractCircularly polarized luminescent inorganics arouses attentions due to scalable preparation and versatile chiral optoelectronic applications. Here, strong circularly polarized luminescence (CPL) activity has been developed from self‐assembled cellulose nanocrystals decorated with blue emitting silicon quantum dots (QDs). The electrostatic attraction promotes the successful incorporation of QDs into chiral template matrix to form homogeneous hybrid nanoarchitecture films. It is found that their circular dichroism behaviors are closely related to the photonic band gap (PBG) while the CPL behaviors are determined by the QDs and PBG simultaneously. Furthermore, the as‐prepared chiral composite thin films have been employed as an efficient circularly polarized light source for preparing enantioselective polymer, which can induce chirality and photopolymerization simultaneously. Such strong CPL activity in nanoarchitecture films is highly promising for future inorganic optoelectronics.

Winding number statistics of a parametric chiral unitary random matrix ensemble* *Dedicated to the Memory of Fritz Haake.

The winding number is a concept in complex analysis which has, in the presence of chiral symmetry, a physics interpretation as the topological index belonging to gapped phases of fermions. We study statistical properties of this topological quantity. To this end, we set up a random matrix model for a chiral unitary system with a parametric dependence. We analytically calculate the discrete probability distribution of the winding numbers, as well as the parametric correlations functions of the winding number density. Moreover, we address aspects of universality for the two-point function of the winding number density by identifying a proper unfolding procedure. We conjecture the unfolded two-point function to be universal.

Trace anomaly for Weyl fermions using the Breitenlohner-Maison scheme for \u03b3*

We revisit the computation of the trace anomaly for Weyl fermions using dimensional regularization. For a consistent treatment of the chiral gamma matrix γ* in dimensional regularization, we work in n dimensions from the very beginning and use the Breitenlohner-Maison scheme to define γ*. We show that the parity-odd contribution to the trace anomaly vanishes (for which the use of dimension-dependent identities is crucial), and that the parity-even contribution is half the one of a Dirac fermion. To arrive at this result, we compute the full renormalized expectation value of the fermion stress tensor to second order in perturbations around Minkowski spacetime, and also show that it is conserved.

On the Optical Activity of Poly(l-lactic acid) (PLLA) Oligomers and Polymer: Detection of Multiple Cotton Effect on Thin PLLA Solid Film Loaded with Two Dyes

Optical rotatory dispersion (ORD) is a beautiful analytical technique for the study of chiral molecules and polymers. In this study, ORD was applied successfully to follow the degree of polycondensation of l-(+)-lactic acid toward the formation of poly(lactic acid) oligomers (PLAO) and high molecular weight poly(l-lactic acid) (PLLA) in a simple esterification reaction equipment. PLLA is a biodegradable polymer obtainable from renewable raw materials. The racemization of the intrinsically isotactic PLLA through thermal treatment can be easily followed through the use of ORD spectroscopy. Organic or molecular electronics is a hot topic dealing with the combination of π-conjugated organic compounds and polymers with specific properties (e.g., chirality) which can be exploited to construct optoelectronic devices, such as organic light-emitting diodes (OLEDs), organic photovoltaic (OPV) high efficiency cells, switchable chirality devices, organic field-effect transistors (OFETs), and so on. ORD spectroscopy was applied to study either the gigantic optical rotation of PLLA films, as well as to detect successfully the excitonic coupling, occurring in thin solid PLLA green film loaded with a combination of two dyes: SY96 (a pyrazolone dye) and PB16 (the metal-free phthalocyanine pigment). The latter compound PLLA loaded with SY96 and PB16 shows a really gigantic optical activity in addition to typical ORD signal due to exciton coupling and may be considered as a simple and easily accessible model composite of a chiral polymer matrix combined with π-conjugated dyes for molecular electronics studies.

Spectral statistics of multiparametric Gaussian ensembles with chiral symmetry.

The statistics of chiral matrix ensembles with uncorrelated but multivariate Gaussian distributed elements is intuitively expected to be driven by many parameters. Contrary to intuition, however, our theoretical analysis reveals the existence of a single parameter, a function of all ensemble parameters, which governs the dynamics of spectral statistics. The analysis not only extends the formulation (known as complexity parameter formulation) for Hermitian ensembles without chirality to those with it but also reveals the underlying connection between chiral complex systems with seemingly different system conditions as well as between other complex systems, e.g., multiparametric Wishart ensembles as well as generalized Calogero-Sutherland Hamiltonians.

Photo-Tunable Azobenzene-Anthraquinone Schiff Base Copper Complexes as Mediators for Laccase in Biofuel Cell Cathode

Induced chirality (achiral target in chiral matrix such as proteins) sometimes play a useful role in evaluating supramolecular systems involving biomolecules. Enzymatic fuel cells, which generate electricity via enzymatic redox reactions at electrodes hold a significant potential for sustainable power. Bacterial laccase, a multi-copper oxidase, was used in the cathodic compartment of the enzymatic biofuel cells because of its low redox potential. Three new salen Cu(II) complexes were designed and investigated as mediators. The Schiff base ligands consisted of both a redox-active (anthraquinone) and a photochromic (azobenzene) moiety. The interaction between laccase and a mediator was examined with induced circular dichroism (CD) and the docking tool to observe in which of the laccase domains the mediators bind as well as study the photo-induced tuning of both the cis-trans photoisomerization and orientation by the Weigert effect. Both the electrochemical and photochromic properties are also discussed and compared using density functional theory (DFT), time-dependent (TD)-DFT, and docking simulations.

A Semisynthetic Peptide−Metalloporphyrin Responsive Matrix for Artificial Photosynthesis

AbstractThe CsmA protein from the baseplate of the Chlorobaculum tepidum is proposed as an attractive motif for the engineering of semisynthetic materials for artificial photosynthesis. We perform self‐assembly of zinc protoporphyrin IX (ZnPP) with a truncated CsmA (tCsmA) amphipathic peptide scaffold for the bottom‐up construction of a semisynthetic matrix for energy transfer. The resulting self‐assembly shows an extended periodic structure with 72 helical symmetry. The complex is able to maintain a good photostability for at least 30 min when the concentration is more than 20 μM, and almost 100 % harvested energy can be transferred to the acceptor cation radical methyl viologen (MV+). The excitation‐energy transfer rate of the complex was increased from the ns−1 scale to the ps−1 scale that is comparable to natural light‐harvesting antenna systems. It contributes to converging evidence that chiral responsive matrix assemblies can be developed for efficient light energy harvesting in artificial photosynthesis.

Thermodynamics and phase diagrams of Polyakov-loop extended chiral models

We study the thermodynamics and phase diagrams of two-flavor quantum chromodynamics using the Polyakov-loop extended quark-meson (PQM) model and the Pisarski-Skokov chiral matrix ($\chi M$) model. At temperatures up to $T\approx2T_c$ and baryon chemical potentials up to $\mu_B=400\ \rm{MeV}$, both models show reasonable agreement with the pressure, energy density, and interaction measure as calculated on the lattice. The Polyakov loop is found to rise significantly faster with temperature in models than on the lattice. In the low-temperature and high baryon density regime, the two models predict different states of matter; The PQM model predicts a confined and chirally restored phase, while the $\chi M$ model predicts a deconfined and chirally restored phase. At finite isospin density and zero baryon density, the onset of pion condensation at $T=0$ is at $\mu_I={1\over2}m_{\pi}$, and the transition is second order at all temperatures. The transition temperature for pion condensation coincides with that of the chiral transition for values of the isospin chemical potential larger than approximately $110\ \rm{MeV}$. In the $\chi M$ model they also coincide with the transition temperature for deconfinement. The results are in good overall agreement with recent lattice simulations of the $\mu_I$--$T$ phase diagram.

Electrically modulated optical properties of fluorescent chiral nematic liquid crystals

Due to the superior optical properties and tremendous application prospects in the field of optical devices, both rare earth complex (REC) and chiral nematic liquid crystal (CNLC) have attracted widespread attention in the fields of theoretical research and engineering applications. Among the research on the optical behaviors of CNLC or REC, the controllable modulation of selective reflection of CNLCs and emitted fluorescence of RECs is of great significance to fabricated tunable optical materials. In this study, europium (III) complexes are dissolved and assembled in the chiral matrix of CNLCs to form binary CNLC-REC composites due to excellent compatibility between RECs and CNLCs. The selective reflection combined with the photoluminescence of binary fluorescent CNLCs are investigated, an electrically-controlled microscopic structure model is established to elaborate the dual-mode optical modulation based on the stable CNLC-REC composites. The reflectance of CNLCs can be tuned in the process from planar state with brilliant Bragg reflection to focal conic state with chaotic scattering, the intensity of fluorescence emitted by RECs can be modulated due to the increased scattering of incident UV light on the surface of CNLC-REC composite films. Furthermore, the dual-mode optical modulation can be operated at low voltages and the response time is within 3 ms. This facile and ultrafast methodology can be used to develop state-of-the-art tunable optical devices in the fields of LC display, fluorescent display and optical sensors.

Programmable Supra-Assembly of a DNA Surface Adapter for Tunable Chiral Directional Self-Assembly of Gold Nanorods.

An important challenge in molecular assembly and hierarchical molecular engineering is to control and program the directional self-assembly into chiral structures. Here, we present a versatile DNA surface adapter that can programmably self-assemble into various chiral supramolecular architectures, thereby regulating the chiral directional "bonding" of gold nanorods decorated by the surface adapter. Distinct optical chirality relevant to the ensemble conformation is demonstrated from the assembled novel stair-like and coil-like gold nanorod chiral metastructures, which is strongly affected by the spatial arrangement of neighboring nanorod pair. Our strategy provides new avenues for fabrication of tunable optical metamaterials by manipulating the directional self-assembly of nanoparticles using programmable surface adapters.

Chiroplasmonic magnetic gold nanocomposites produced by one-step aqueous method using κ-carrageenan

Novel water-soluble chiroplasmonic nanobiocomposites with directly varied gold content were synthesized by a one-step redox method in water using a biocompatible polysaccharide κ-carrageenan (industrial product from algae) as both reducing and stabilizing matrix. The influence of the reactants ratio, temperature, and pH on the reaction was studied and the optimal reaction parameters were found. The structure and the properties of composite nanomaterials were examined in solid state and aqueous solutions by using complementary physical-chemical methods X-ray diffraction analysis, transmission electron microscopy, spectroscopy of electron paramagnetic resonance, atomic absorption and optical spectroscopy, polarimetry including optical rotatory dispersion with registration of interphase-crossbred Cotton effect of a chiral polysaccharide matrix on plasmonic chromophore of gold nanoparticles, dynamic and static light scattering. The new perspective multi-purpose nanocomposites demonstrate a complex of chiroplasmonic and magnetic properties, imparted by both nanoparticles and radicals enriched chiral polysaccharide matrix.

Optical band gap in a nanocomposite structurally chiral medium

We analyzed the optical band gaps for axially propagating electromagnetic waves throughout a nanocomposite structurally chiral medium. This medium is made of metallic nanoballs (silver) randomly dispersed in a structurally chiral material whose dielectric properties can be represented by a resonant effective uniaxial tensor. The structurally chiral material is taken to possess locally a $\overline{4}2m$ point group symmetry. We found that the band-gap properties of the periodic system depends strongly on the volume fraction of nanoparticles in the chiral matrix. Particularly, we observed splitting of the bands and the creation of new sub band gaps when the resonance frequency of the composite medium lies within the band gap without inclusions.

Chiral matrix model for the phase transition in QCD

We discuss how to model chiral symmetry restoration with an effective theory of deconfinement. The model includes fluctuations in the quarks to one loop order, while the mesons of the sigma model are treated in mean field approximation. We note that a new counterterm is required at T=0, and a novel form of symmetry breaking at T≠0. We discuss how to incorporate tetraquark states, representing JP=0+ scalar mesons, into a linear sigma model. We suggest that their effect upon the chiral phase transition is small.