Journal of Physics. Condensed Matter : An Institute of Physics Journal

Bottom-up synthesis from molecular precursors is a powerful route for the creation of novel synthetic carbon-based low-dimensional materials, such as planar carbon lattices. The wealth of conceivable precursor molecules introduces a significant number of degrees-of-freedom for the design of materials with defined physical properties. In this context, a priori knowledge of the electronic, vibrational and optical properties provided by modern ab initio simulation methods can act as a valuable guide for the design of novel synthetic carbon-based building blocks...

Novel hyperuniform materials are emerging as an active field of applied and basic research since they can be designed to have exceptional physical properties. This ubiquitous state of matter presents a hidden order that is characterized by the density of constituents of the system being uniform
at large scales, as in a perfect crystal, although they can be isotropic and disordered like a liquid. In the quest for synthesizing hyperuniform materials in experimental conditions, the impact of finite-size effects remains as an open question to be addressed...

Disorder hyperuniformity is a recently discovered exotic state of many-body systems that possess a hidden order in between that of a perfect crystal and a completely disordered system. Recently, this novel disordered state has been observed in a number of quantum materials including amorphous 2D graphene and silica, which are endowed with unexpected electronic transport properties. Here, we numerically investigate 1D atomic chain models, including perfect crystalline, disordered stealthy hyperuniform (SHU) as well as randomly perturbed atom packing configurations to obtain a quantitative understanding of how the unique stealthy hyperuniform disorder affects the vibrational properties of these low-dimensional materials...

In recent years, higher-order topological phases have attracted great interest in various fields of physics. These phases have protected boundary states at lower-dimensional boundaries than the conventional first-order topological phases due to the higher-order bulk-boundary correspondence. In this review, we summarize current research progress on higher-order topological phases in both crystalline and non-crystalline systems. We firstly introduce prototypical models of higher-order topological phases in crystals and their topological characterizations...

Cell-matrix adhesions connect the cytoskeleton to the extracellular environment and are essential for maintaining the integrity of tissue and whole organisms. Remarkably, cell adhesions can adapt their size and composition to an applied force such that their size and strength increases proportionally to the load. Mathematical models for the clutch-like force transmission at adhesions are frequently based on the assumption that mechanical load is applied tangentially to the adhesion plane. Recently, we suggested a molecular mechanism that can explain adhesion growth under load for planar cell adhesions...

Previous studies on the generalized XY model have concentrated on the equilibrium phase diagram and the equilibrium nature of distinct phases under varying parameter conditions. We direct our attention towards examining the system's evolution towards equilibrium states across different parameter values, specifically by varying the relative strengths of ferromagnetic and nematic interactions. We study the kinetics of the system, using the temporal annihilation dynamics of defects at varying temperatures and its impact on the coarsening behavior of the system...

We performed a comprehensive study on the electrical characteristics, lattice dynamics, and structural stability of Cs2 SnBr6 double perovskites. The origin and symmetry of the four phonon modes active in Raman scattering are clearly identified by combining mirco-Raman spectroscopy and first-principle calculations, that is, one external translational mode of the Cs+ lattice with T2g symmetry and three internal modes of the octahedral with A1g, Eg, and T2g symmetries. Our results show a significant correlation with first-principles calculations, validating using a band-structured electronic approach to understanding the behavior of charge carriers, and electron-phonon interactions in Cs2 SnBr6 ...

The presence of hematite (Fe2O3) clusters at low coverage on titanium dioxide (TiO2) sur-
face has been observed to enhance photocatalytic activity, while excess loading of hematite is
detrimental. We conduct a comprehensive density functional theory study of Fe2O3 clusters
adsorbed on the anatase TiO2 (101) surface to investigate the effect of Fe2O3 on TiO2. Our
study shows that TiO2 exhibits improved photocatalytic properties with hematite clusters at
low coverage, as evidenced by a systematic study conducted by increasing the number of cluster
adsorbates...

We present the ab-initio temperature and pressure dependent thermoelastic properties of body-centered cubic tungsten. The temperature dependent quasi-harmonic elastic constants are computed at several reference volumes including both the phonon and the electronic excitations contribution to the free energy and interpolated at different temperatures and pressures. Good agreement with the experimental elastic constants on a single crystal at ambient pressure is found.
The pressure and temperature dependence of the shear sound velocity measured on polycrystalline tungsten by Qi et al...

Flexible photodetectors have exotic significance in recent years due to their enchanting potential in future optoelectronics. Moreover, paper-based fabricated photodetectors with outstanding flexibility unlock new avenues for future wearable electronics. Such photodetector has captured scientific interest for its efficient photoresponse properties due to the extraordinary assets like significant absorptive efficiency, surface morphology, material composition, affordability, bendability, and biodegradability...

\textit{Holey Graphene} (HG) is a widely used graphene material for the synthesis of high-purity and highly crystalline materials. The electronic properties of a periodic distribution of lattice holes are explored here, demonstrating the emergence of flat bands. It is established that such flat bands arise as a consequence of an induced sublattice site imbalance, i.e., by having more sites in one of the graphene's bipartite sublattice than in the other. This is equivalent to the breaking of a path-exchange symmetry...

Magnonics is a research field that has gained an increasing interest in both the fundamental and applied sciences in recent years. This field aims to explore and functionalize collective spin excitations in magnetically ordered materials for modern information technologies, sensing applications, and advanced computational schemes. Spin waves, also known as magnons, carry spin angular momenta that allow for the transmission, storage, and processing of information without moving charges. In integrated circuits, magnons enable on-chip data processing at ultrahigh frequencies without the Joule heating, which currently limits clock frequencies in conventional data processors to a few GHz...

We compute the magnetoelectric conductivity tensors in planar Hall set-ups, which are built with tilted Weyl semimetals (WSMs) and multi-Weyl semimetals (mWSMs), considering all possible relative orientations of the electromagnetic fields ($\mathbf E $ and $\mathbf B $) and the direction of the tilt. The non-Drude part of the response arises from a nonzero Berry curvature in the vicinity of the WSM/mWSM node under consideration. Only in the presence of a nonzero tilt do we find linear-in-$ | \mathbf B| $ terms in set-ups where the tilt-axis is not perpendicular to the plane spanned by $\mathbf E $ and $ \mathbf B $...

We computed the phase diagram of zigzag graphene nanoribbons as a function of on-site repulsion, doping, and disorder strength. The topologically ordered phase undergoes topological phase transitions into crossover phases, which are new disordered phases with non-universal topological entanglement entropy that exhibits significant variance. We explored the nature of non-local correlations in both the topologically ordered and crossover phases. In the presence of localization effects, strong on-site repulsion and/or doping weaken non-local correlations between the opposite zigzag edges of the topologically ordered phase...

Inverse spinel ferrimagnetic NiCo2 O4 (NCO) exhibits volatile physical properties due to the complex ion/valence occupation, which complicates the study its intrinsic properties. In this work, robust room temperature perpendicular magnetic anisotropy (PMA) is distinctly observed in high-quality RF-sputtered NCO film down to 3 uc (2.4 nm), confirmed by the room temperature anomalous Hall effect. The NCO films show a good metallic conductivity with a dimensional driven metal-insulator transition. The scaling relation between anomalous Hall conductivity (σxy ) and the longitudinal conductivity (σxx ) reveals the dirty metal behavior in conjunction with the contribution of intrinsic Berry phase or disorder-enhanced electron correlation contribute to the anomalous Hall effect for thick films while the dirty scaling law dominates for the thin films...

Most of normal proliferative epithelia of plants and metazoans are topologically invariant and characterized by similar cell distributions according to the number of cell neighbors (DCNs). Here we study peculiarities of these distributions and explain why the DCN obtained from the location of intercellular boundaries and that based on the Voronoi tessellation with nodes located on cell nuclei may differ from each other. As we demonstrate, special microdomains where four or more intercellular boundaries converge are topologically charged...

A new cage-structured compound - HfMn2 Zn20 - belonging to the AB 2 C 20 ( A , B = transition or rare earth metals, and C = Al, Zn, or Cd) family of structures has been synthesized via the self-flux method. The new compound crystallizes in the space group Fd -3 m with lattice parameter a ≈ 14.0543(2) Å ( Z = 8) and exhibits non-stoichiometry due to Mn/Zn mixing on the Mn-site and an underoccupied Hf-site. The structure refines to Hf0.93 Mn1.63 Zn20.37 and follows lattice size trends when compared to other Hf M 2 Zn20 ( M = Fe, Co, and Ni) structures...

In this paper, the dispersion relations of the surface plasmon polaritons in TI nanowires have been investigated. For simplicity, TI nanowire has been modeled as a dielectric cylinder with a conductive surface, the conductivity of which is an anti-symmetric tensor. The off-diagonal terms of the conductivity tensor only slightly change the dispersion relations. Due to small conductivities, these surface plasmon polaritons have extremely large wavenumbers and azimuthal indices; the electric fields are tightly confined near the conductive surface...

Supercapacitors have become one of the most popular energy-storage devices for high power density and fast charging/discharging capability. Polyaniline is a class of conductive polymer materials with ultra-high specific capacitance, and the excellent mechanical properties will play a key role in the research of flexible supercapacitors. The synergistic effect between polyaniline and graphene is often used to overcome their respective inherent shortcomings, thus the high-performance polyaniline-graphene based nanocomposite electrode materials can be prepared...

Electrical resistivity experiments show superconductivity at Tc= 1.1 K in a high-quality single crystal of trigonal γ-PtBi2, with an enhanced critical magnetic field µ0Hc2(0) ≥ 1.5 Tesla and a low critical current-density Jc(0) ≈ 40 A/cm2 at H = 0. Both Tc and Hc2(0) are the highest reported values for stoichiometric bulk samples at zero pressure. We found a weak Hc2 anisotropy with Γ = Hab c2 /Hc c2 < 1, which is unusual among superconductors. Under a magnetic field, the superconducting transition becomes broader and asymmetric...