One-dimensional Atomic Chains Research Articles

Electric-field-induced enhancement of exciton binding energy in one-dimensional phosphorene atomic chain

An electric field normally increases the separation between the electron and hole in an exciton without intrinsic polarization and suppresses their Coulombic interaction, resulting in the reduction of its binding energy. Our study of one-dimensional (1D) excitons in phosphorene atomic chains, by using the exact diagonalization method, however, reveals that an electric field applied along the chain axis actually increases the exciton binding energies. Further analysis shows that the electric field tends to enhance the long-range interaction between the electron and hole while suppressing their short-range interaction by inducing an alternating charge distribution along the atomic chain. The zigzag symmetry is believed to account for this unique excitonic phenomenon in the 1D system.

Synthesis of low-dimensional metal halide CsAgCl2 for X-ray scintillation applications

Low-dimensional metal halides, which possess efficient luminescent properties, have garnered significant interest in the fields of optoelectronics and radiation detection. This study introduces novel lead-free silver-based metal halide material, CsAgCl2 microcrystals (MCs). These MCs have a one-dimensional atomic chain structure and a unique [AgCl5]4- tetragonal shared triangular configuration. CsAgCl2 MCs exhibit excellent performance as X-ray scintillators due to their bright broadband yellow emission and fast decay time in the microsecond range. The large Stokes shift of 350 nm is produced by self-trapped exciton emission. In X-ray scintillation applications, CsAgCl2 MCs demonstrate a high light yield of 13280 photons/MeV and a wide range of linear scintillation response. It is noteworthy that the CsAgCl2 MCs maintain good stability under both atmospheric conditions and continuous X-ray irradiation. The sample was used in an X-ray imaging screen, which clearly presented the X-ray projection image of a wooden stick. As a result, this research not only contributes to the collection of lead-free metal halide scintillators but also indicates that CsAgCl2 MCs have a wide range of future applications and potential in areas such as medical imaging, scientific research, and diagnostic and detection technologies.

First principles study of electronic structure of x-form phthalocyanine crystals doped with one-dimensional iodine atomic chains

The x-form phthalocyanine (Pc) crystal is composed of a square-lattice arrangement of one-dimensional and double-period molecular chains with molecular planes normal to the stacking direction, and doped iodine (I) atomic chains between these molecular chains are known to induce the insulator-metal transition. Using the van der Waals density functional method, we investigate the electronic structure of a single x-form silicon Pc (x-SiPc) chain and the x-SiPc crystal undoped and doped with I atomic chains in a comparative manner. Although a SiPc molecule has a Si pz derived orbital just above the LUMO, the aligned Si atoms in x-crystals, each of which is at the center of the molecular plane, dimerize in the stacking direction, which prevents formation of a Si metallic band. In a single SiPc chain, two molecules in each primitive unit cell are stacked face-to-face with a staggering angle of 45°. However, when these molecular chains aggregate to create x-crystals, the staggering angle deviates from 45° to about 40° to form H–H bonding orbitals like H2 molecules between neighboring molecular planes in the lateral direction. Doping of the I atomic chains converts half-filling of the doubly degenerate bands to a lower band occupancy, which corresponds to the insulator-metal transition observed experimentally. The equally spaced I atomic chains create a metallic band due to pz-orbital overlapping with an effective-mass ratio of 0.15. Although the SiPc chains operate to create equally spaced I atomic chains, the effect of I atoms trying to trimerize is larger. This trimerization prevents pz orbitals of I atoms from making a metallic band.

Electronic structure and intrinsic mobilities of one-dimensional CuO2 atomic wires: A first-principles study

Herein, the electronic structure and intrinsic carrier mobility of the one-dimensional CuO2 atomic chain were studied by first-principles calculations. The band structure of the CuO2 atomic chain was obtained using the HSE06 hybrid functional with spin polarization. The results show that the band gap and hole effective mass of antiferromagnetic (ferromagnetic) CuO2 were 1.42 (0.38) eV and 1.53 (0.81) m0, respectively. The magnetism in CuO2 mainly originates from O atoms, consistent with the experiment, and the magnetic moment of these O atoms in the antiferromagnetic (ferromagnetic) state was ±0.58 (+0.41) μB. The intrinsic carriers of CuO2 have relatively high hole mobility (318 cm2 V−1 s−1) and extremely low electron mobility. Combined with the phonon dispersion calculation, the CuO2 atomic chain is an excellent and structurally stable p-type one-dimensional semiconductor material. Our work is expected to provide useful guidance for thermal transport materials containing CuO2 atomic chain substructure.

Research on solitons’ interactions in one-dimensional indium chains on Si(111) surfaces

Solitons have garnered significant attention across various fields, yet a contentious debate persists regarding the precise structure of solitons on indium chains. Currently, multiple forms of solitons in one-dimensional atomic chains have been reported. STM provides an effective means to study the precise atomic structure of solitons, particularly their dynamics and interactions. However, limited research has been conducted on soliton interactions and soliton-chain interactions, despite their profound impact on relative soliton motions and the overall physical properties of the system. In this work, we characterized the structures of the soliton dimer and trimer, observed the displacements induced by the soliton entity and statisticized the dynamic behaviors of soliton dimers over time evolution or temperature. To reveal the soliton mechanism, we further utilized STM to investigate the CDWs between two solitons when two monomers were encountered. Additionally, we achieved the manipulation of the monomer on the indium chain by the STM tip. Our work serves as an important approach to elucidate interactions in correlated electronic systems and advance the development of potential topological soliton computers.

Efficient Synthesis of Highly Crystalline One-Dimensional CrCl3 Atomic Chains with a Spin Glass State.

One-dimensional (1D) magnetic material systems have attracted widespread interest from researchers because of their peculiar physical properties and potential applications in spintronics devices. However, the synthesis of 1D magnetic atomic chains has seldom been investigated. Here, we developed an iodine-assisted vacuum chemical vapor-phase transport (I-VCVT) method, utilizing single-walled carbon nanotubes (SWCNTs) with 1D cavities as templates, and high-quality and high-efficiency fabrication of 1D atomic chains of CrCl3 was achieved. Furthermore, the structure of CrCl3 atomic chains in the confined space of SWCNTs was analyzed in detail, and the charge transfer between the 1D atomic chains and SWCNTs was investigated through spectroscopic characterization. A comprehensive study of the dynamic magnetic properties revealed the existence of spin glass states and freezing of the 1D CrCl3 atomic chains at around 3 K, which has never been seen in bulk CrCl3. Our work established an effective strategy for the control synthesis of 1D magnetic atomic chains with promising potential applications in further magnetic-based spintronics devices.

Collective oscillations of systems of Xe atoms in a groove between two carbon nanotubes

The collective oscillations of systems of Xe atoms adsorbed in a groove between two carbon nanotubes have been studied by the method of molecular dynamics. The one-dimensional and three-chain structures of atoms that appear in such grooves are considered depending on the number of particles, temperature, and external potentials. It is shown that the infinite one-dimensional structures of Xe atoms are stable at finite temperatures only in the presence of such potentials acting in the direction normal to the axis of the structure. The oscillation spectrum is found, which is in accordance with theoretical calculations of the dispersion laws of collective modes. Collective oscillations of three-chain structures have been studied. The theoretical calculation of the laws of dispersion of modes, carried out by the method of equations of motion for small displacements of atoms from the equilibrium position, showed that the collective modes of the system show a great similarity with the corresponding dispersion laws of a one-dimensional chain of atoms. At the same time, it was found that a torsion mode arises, which is characteristic of a three-chain structure. The calculation agrees well with the spectrum of oscillations obtained by the molecular dynamics method. Using the established mode dispersion, the heat capacity of Xe chains is calculated within the framework of the Einstein model. The calculation results are in good agreement with the experimental data in the temperature range of up to 35–40 K, which can be explained if we assume the presence of both one-dimensional and three-chain structures of Xe atoms adsorbed in the grooves between carbon nanotubes. The effect of temperature on the stability of Xe atomic structures on nanotubes has been studied, and it has been shown that one-dimensional structures start to defragment at temperatures higher than 60 K, whereas three-chain structures defragment at temperatures higher than 90 K.

Distribution of Electron Density in Self-Assembled One-Dimensional Chains of Si Atoms.

Scanning tunneling microscopy measurements of height profiles, along the chains of Si atoms on the terrace edges of a perfectly ordered Si(553)-Au surface, reveal an STM bias-dependent mixed periodicity with periods of one, two and one and a half lattice constants. The simple linear chain model usually observed with STM cannot explain the unexpected fractional periodicity in the height profile. It was found that the edge Si chain stands for, in fact, a zigzag structure, which is composed of two neighboring rows of Si atoms and was detected in the STM experiments. Tight-binding calculations of the local density of states and charge occupancy along the chain explain the voltage-dependent modulations of the STM profiles and show that oscillation periods are determined mainly by the surface and STM tip Fermi energies.

Permittivity from first principles

Dielectric properties of materials are generally introduced phenomenologically through empirical values of permittivity. While this approach is necessary for practical work, it must be recognized that it bypasses the question of whether it is possible to predict permittivity values from first principles and thus get a deeper grasp of the physics involved in bridging the microscopic system and its macroscopic properties. Theoretical frameworks to gain insight and to compute exactly permittivity values are desirable to understand the nuances that go into building this bridge. We introduce here such a theoretical model system to gain physical intuition on the microscopic origin of the permittivity. The system consists of electrons in a one-dimensional atomic chain in the presence of an external electric field, where each atom is a binding site. We first consider a single atom in an external field to study atomic polarization, justify the model, tune the parameters, and compare with perturbative approaches. We then consider the assembly of many such atoms in a periodic arrangement and study its band-structure, including explicitly the external electric field. Last, within this model we develop explicit formulas for the permittivity in terms of relevant physical parameters. Finally, we obtain a numerically value for the permittivity of the system for typical values of binding energy and electric field.

Modulation instability gain and localized waves in the modified Frenkel–Kontorova model with high-order nonlinearities

In this paper, modulation instability and nonlinear supratransmission are investigated in a one-dimensional chain of atoms using cubic–quartic nonlinearity coefficients. As a result, we establish the discrete nonlinear evolution equation by using the multi-scale scheme. To compute the modulation instability gain, the linearizing technique is employed. The effect of the higher nonlinear component on modulation instability is particularly examined. Following that, full numerical integration was performed to identify modulated wave patterns as well as the appearance of a rogue wave. Through the nonlinear supratransmission phenomenon, one end of the discrete model is driven into the forbidden bandgap. As a consequence, for driving amplitudes above the supratransmission threshold, the bright soliton and modulated wave patterns are satisfied. An important behavior is observed in the transient range of time of propagation when the bright soliton wave turns into a chaotic soliton wave. These results corroborate our analytical investigations on the modulation instability and show that the one-dimensional chain of atoms is a fruitful medium to generate long-lived modulated waves.

Unconventional Self-Reconstructed Trimer-like Metal Zigzag Edge of 1T-Phase Transition Metal Dichalcogenides

Undercoordination-induced slight bond contraction of the pristine edge is a conventional edge self-reconstructed pattern in two-dimensional materials that generally cannot drive the edge into its ground state. Despite reports of unconventional edge self-reconstructed patterns of 1H-phase transition metal dichalcogenides (TMDCs), there have been no reports of sister 1T-phase TMDCs. Here, we predict an unconventional (2 × 1) edge self-reconstructed pattern for 1T-TMDCs by considering 1T-TiTe2. A novel self-reconstructed trimer-like metal zigzag edge (TMZ edge) with one-dimensional metal atomic chains and Ti3 trimers is uncovered. Its metal triatomic 3d orbital coupling leads to Ti3 trimerization. This TMZ edge occurs in group IV, V, and X 1T-TMDCs and has an energetic advantage far beyond conventional bond contraction. The unique triatomic synergistic effect results in better catalysis of the hydrogen evolution reaction (HER) for the 1T-TMDCs than with commercial platinum-based catalysts. This study provides a new strategy for maximizing the HER catalytic efficiency of 1T-TMDCs by using atomic edge engineering.

Tunning the tilt of the Dirac cone by atomic manipulations in 8Pmmn borophene

Two dimensional quantum materials possessing Dirac cones in their spectrum are fascinating due to their emergent low-energy Dirac fermions. In 8Pmmn borophene the Dirac cone is furthermore tilted, which is a proxy for spacetime geometry, since the future light-cone depends on the underlying metric. Therefore it is important to understand the microscopic origin of the tilt. Here, based on ab-initio calculations, we decipher the atomistic mechanism of the formation of tilt. First, nearest-neighbor hopping on a buckled honeycomb lattice forms an upright Dirac cone. Then, the difference in the renormalized anisotropic second-neighbor hopping, formed by virtual hoppings on one-dimensional chains of atoms, tilts the Dirac cone. We construct an accurate tight-binding model on honeycomb graph for analytical investigation, and we find that substitution of certain boron atoms by carbon provides a way to change the tilt of the cone.

Design of Lanthanide Single-Chain Magnets Based on Tubular Segment Clusters

One-dimensional (1D) atomic chains that exhibit large magnetic anisotropy are highly relevant to spintronic applications. Such 1D magnetic systems have usually been produced by atom/molecular assembling on solid surfaces or by coordination polymers. Here, we demonstrate an alternative approach for the formation of a confined ferromagnetic holmium (Ho) atom chain, which is composed of repeating units of the tubular Ho doped boron (B) cluster HoB20. The tubular HoB20 is discovered by the global structural search of a series of small-sized boron clusters doped by a single Ho atom (HoBn, n = 12, 14, 16, 18, 20) using ab initio calculations. Electronic analysis reveals that the individual HoB20 cluster is stabilized by the double σ + π aromaticity. Extending the tubular structure results in a single Ho atom chain being confined inside a boron nanotube, which shows ferromagnetic behaviors and a large magnetic anisotropy of more than 40 meV/atom. Our findings indicate that the magnetic lanthanide chain is a promising candidate for high-density magnetic information storage.

Flat Bands in Network Superstructures of Atomic Chains

We investigate the origin of the ubiquitous existence of flat bands in the network superstructures of atomic chains, where one-dimensional (1D) atomic chains array periodically. While there can be many ways to connect those chains, we consider two representative ways of linking them, the dot-type and triangle-type links. Then, we construct a variety of superstructures, such as the square, rectangular, and honeycomb network superstructures with dot-type links and the honeycomb superstructure with triangle-type links. These links provide the wavefunctions with an opportunity to have destructive interference, which stabilizes the compact localized state (CLS). In the network superstructures, there exist multiple flat bands proportional to the number of atoms of each chain, and the corresponding eigenenergies can be found from the stability condition of the compact localized state. Finally, we demonstrate that the finite bandwidth of the nearly flat bands of the network superstructures arising from the next-nearest-neighbor hopping processes can be suppressed by increasing the length of the chains consisting of the superstructures.

Lattice Dynamics Models to Predict Transmission Properties of Flexural Waves in One-Dimensional Atom Chains with Defects

Lattice Dynamics Models to Predict Transmission Properties of Flexural Waves in One-Dimensional Atom Chains with Defects

Ga3Te3I: novel 1D and 2D semiconductor materials with promising electronic and optical properties

Due to their unique properties and potential applications, low-dimensional van der Waals (vdW) materials, including two-dimensional (2D) nanosheets and one-dimensional (1D) atomic chains, have caused widespread interest. Herein, based on first-principles calculations, we introduce a Ga3Te3I material as an example of novel 2D- and 1D-vdW-based materials. The 2D monlayer and 1D nanochain of Ga3Te3I can be isolated from their bulk counterpart by mechanical exfoliation and possess good dynamical and thermal stability. The electronic, transport, and optical properties of 2D monolayer and 1D nanochain were studied comprehensively. Remarkably, the modest band gaps, 1.98 eV and 2.29 eV for 2D monolayer and 1D nanochain, endow low-dimensional Ga3Te3I materials with promising visible light-harvesting capability and charge carrier mobility. And the electronic properties can be effectively adjusted by the applied strain. Interestingly, 1D Ga3Te3I nanochain exhibits superior mechanical elasticity, which is comparable to those of most reported 1D materials. These highly desirable properties make low-dimensional Ga3Te3I materials reliable candidates in future electronic, optoelectronic, and photovoltaic devices.

Vanadium Tetrasulfide for Next-Generation Rechargeable Batteries: Advances and Challenges.

Alkali metal-ion batteries (SIBs and PIBs) and multivalent metal-ion batteries (ZIBs, MIBs, and AIBs), among the next-generation rechargeable batteries, are deemed appealing alternatives to lithium-ion batteries (LIBs) because of their cost competitiveness. Improving the electrochemical properties of electrode materials can greatly accelerate the pace of development in battery systems to cover the increasing demands of realistic applications. Vanadium tetrasulfide (VS4 ) is known as a prospective electrode material due to its unique one-dimensional atomic chain structure with a large chain spacing, weak interactions between adjacent chains, and high sulfur content. This review summarizes the synthetic strategies and recent advances of VS4 as cathodes/anodes for rechargeable batteries. Meanwhile, we describe the structural characteristics and electrochemical properties of VS4 . And we describe in detail its specific applications in batteries such as SIBs, PIBs, ZIBs, MIBs, and AIBs as well as modification strategies. Finally, the opportunities and challenges of VS4 in the domain of energy research are described.

Quantum correlation propagation in a waveguide-QED system with long-range interaction.

We investigate the excitation and correlation propagations among a one-dimensional atom chain with exponentially decaying, ideal long-range, and power-law decaying interactions. We show that although a clear light-cone-like structure can appear in both the excitation and correlation propagation patterns under the exponentially decaying interaction, only an obscure light-cone-like structure appears with multi-power-law decaying interaction and surprisingly an inverse light-cone-like structure appears in the ideal long-range interaction case. The extracted excitation and correlation propagation velocities in the ideal long-range interaction case are about one order of magnitude larger than those in the multi-power-law interaction case and about two orders of magnitude larger than those in the short-range interaction case. These results indicate that the waveguide-quantum electrodynamics system with long-range interaction can boost the quantum information transfer speed and is beneficial for building fast quantum network and scalable quantum computer.

Observation of V-type electromagnetically induced transparency and optical switch in cold Cs atoms by using nanofiber optical lattice

Optical nanofiber (ONF) is a special tool to achieve the interaction between light and matter with ultralow power. In this paper, we demonstrate V-type electromagnetically induced transparency (EIT) in cold atoms trapped by an ONF-based two-color optical lattice. At an optical depth of 7.35, 90% transmission can be achieved by only 7.7 pW coupling power. The EIT peak and linewidth are investigated as a function of the coupling optical power. By modulating the pW-level control beam of the ONF-EIT system in sequence, we further achieve efficient and high contrast control of the probe transmission, as well as its potential application in the field of quantum communication and quantum information science by using one-dimensional atomic chains.

Graph-based discovery and analysis of atomic-scale one-dimensional materials.

Recent decades have witnessed an exponential growth in the discovery of low-dimensional materials (LDMs), benefiting from our unprecedented capabilities in characterizing their structure and chemistry with the aid of advanced computational techniques. Recently, the success of two-dimensional compounds has encouraged extensive research into one-dimensional (1D) atomic chains. Here, we present a methodology for topological classification of structural blocks in bulk crystals based on graph theory, leading to the identification of exfoliable 1D atomic chains and their categorization into a variety of chemical families. A subtle interplay is revealed between the prototypical 1D structural motifs and their chemical space. Leveraging the structure graphs, we elucidate the self-passivation mechanism of 1D compounds imparted by lone electron pairs, and reveal the dependence of the electronic band gap on the cationic percolation network formed by connections between structure units. This graph-theory-based formalism could serve as a source of stimuli for the future design of LDMs.