Local Density Of States Research Articles

Gas sensing properties of alkali metal decorated pristine and defect α-AsP monolayer toward acid SO2 and alkaline NH3 molecules

The sensing properties of Li and Na decorated pristine and defect α-AsP monolayer for acid SO2 and alkaline NH3 toxic gas molecules are systematically studied using first-principles calculations based on density functional theory (DFT-D2 method). The results suggest that the alkali metal atoms decorated defect α-AsP monolayer have moderate adsorption energies for SO2 and NH3 gas molecules, which is conducive to the desorption of gas molecules. In addition, a prominent increase in work function (WF) after SO2 and NH3 adsorption endow Li and Na decorated pristine and defect α-AsP monolayer with high sensitivity, and there is a clear relationship between the change of WF and the direction of charge transfer. The binding mechanism of SO2 and NH3 on different adsorbent models are explored by the electronic local function (ELF) and density of states (DOS) calculation. The results show that the adsorption of SO2 on substrates is mainly determined by electrostatic interaction and NH3 is bound to the substrates by a covalent bond. The adsorption of NH3 enhances the adsorption spectrum intensity of substrates around 150 and 200 nm. Additionally, thermodynamic analysis demonstrate that the Li and Na decorated pristine α-AsP monolayer may be a suitable material for the detection and storage of SO2 and NH3 toxic gas molecules. Therefore, these results can provide practical guidance for the research of promising novel two-dimensional V–V binary AsP-based gas sensors.

Giant tunnel magnetoresistance in two-dimensional van der Waals magnetic tunnel junctions: Ag/CrI3/MoSi2N4/CrI3/Ag

With intrinsic magnetism, two-dimensional (2D) $\mathrm{Cr}{\mathrm{I}}_{3}$ has attracted tremendous interest because of the potential application in magnetic devices of smaller size. We propose to use 2D $\mathrm{Mo}{\mathrm{Si}}_{2}{\mathrm{N}}_{4}$ material, which has remarkable stability, excellent electronic properties, and high mobility, as tunnel barrier in vertical magnetic tunnel junction (MTJ), and demonstrate that it is able to generate a giant tunnel magnetoresistance (TMR) over ${10}^{5}%$ when integrated with $\mathrm{Cr}{\mathrm{I}}_{3}$ ferromagnetic layers and Ag electrodes. Combining with density-functional theory and nonequilibrium Green's function approach, we systematically investigate the electron transmission, band structures, and projected local density of states and elaborate the transmission mechanism. The TMR and spin injection efficiency maintain high values below 0.25 V. These results indicate that $\mathrm{Mo}{\mathrm{Si}}_{2}{\mathrm{N}}_{4}$ is a promising barrier material in future 2D vertical MTJs and provide important guidance for designing devices.

Effects of S-vacancy on electrical performance of monolayer TMD nanoribbons field-effect transistor

In this paper, the electrical properties of a FET based on nanoribbon of transition metal dichalcogenides in the presence of S-vacancy are investigated. The transition metal dichalcogenides (MoS2, MoSe2, WS2, and WSe2) monolayer is utilized as the channel for the FET. The non-equilibrium Green’s function (NEGF) along with the tight-binding method has been employed to study the electrical properties. The local density of states for pristine and defective ribbons are compared and the creation of mid-gap states due to S-vacancy is explored. The I-V characteristic of this FET is investigated. The increasing S-vacancy decreases ON-current whereas, leads to the increment of OFF-current. The considering 1.75% vacancy can decline ON-current 12 times for WSe2 and increases OFF-current 35 times for MoSe2.

High switching ratio and inorganic gas sensing performance in BeN4 based nanodevice: a first-principles study

Recently, Dirac material BeN4 has been synthesized by using laser-heated diamond anvil-groove technology (Bykov et al 2021 Phys. Rev. Lett. 126 175501). BeN4 layer, i.e. beryllonitrene, represents a qualitatively class of two-dimensional (2D) materials that can be built of a metal atom and polymeric nitrogen chains, and hosts anisotropic Dirac fermions. Enlighten by this discovered material, we study the electronic structure, anisotropic transport properties and gas sensitivity of 2D BeN4 using the density functional theory combined with non-equilibrium Green’s function method. The results manifest that the 2D BeN4 shows a typical semi-metallic property. The electronic transport properties of the intrinsic BeN4 devices show a strong anisotropic behavior since electrons transmitting along the armchair direction is much easier than that along the zigzag direction. It directly results in an obvious switching characteristic with the switching ratio up to 105. Then the adsorption characteristics indicate that H2S, CO, CO2 and H2 molecules are physisorption, while the NH3, NO, NO2, SO2 molecules are chemisorption. Among these chemisorption cases, the 2D gas sensor devices show an extremely high response for SO2 recognition, and the high anisotropy of the original 2D BeN4 device still maintains after adsorbing gas molecules. Finally, high switching ratio and inorganic gas sensing performance of BeN4 monolayer could be clearly understood with local density of states, bias-dependent spectra, scattered state distribution. In general, the results indicate that the designed BeN4 devices have potential practical application in high-ratio switching devices and high gas-sensing molecular devices.

The performance analysis of near-field thermophotovoltaics considering temperature dependence of indium tin oxide emitter

Near-field thermophotovoltaics (NFTPV) is of great interest because it can achieve both high power density and high efficiency at medium to high temperature. One key to efficient photovoltaic conversion is an emitter that can selectively emit spectrum. Indium tin oxide (ITO) is considered as the emitter for NFTPV because its plasma frequency is tunable by simple technical means. However, as a typical degenerate semiconductor, the temperature dependence of its dielectric constant is often neglected in studying the performance of NFTPV. Therefore, we propose a NFTPV model considering the temperature-dependent property of ITO. By changing the applied voltage V, the vacuum gap d, and the emitter temperature T1, the performance of NFTPV with and without temperature dependence is compared and shows a significant difference. We find that the heat flux is always underestimated as well as the optimal efficiency is overestimated when the temperature dependence is not considered. At d = 10 nm and T1 = 1000 K, the optimal efficiency is even overestimated by about 270%. Without considering the temperature dependence, the output power is overestimated at d < 20 nm, while the opposite is true at d ≥ 20 nm. We clarify the main reasons for these misjudgments at a small gap originate from the underestimation of the intensity of surface phonon polaritons (SPhPs) below the bandgap and the overestimation of the intensity of surface plasmon polaritons (SPPs) above the bandgap. The main factor affecting the two kinds of surface modes in near-field regime is that high temperatures lead to low electromagnetic local density of states (LDOS) for ITO emitter near the SPPs resonant frequency, but high LDOS in the ultralow frequencies. In a larger gap, it is attributed to the underestimation of the waveguide modes above the bandgap and the nearly-full-band propagation modes. Our work illustrates the necessity of considering temperature dependence, enriches the understanding of NFTPV, and facilitates the development of related applications.

Nonequilibrium spintronic transport through Kondo impurities

In this work we analyze the nonequilibrium transport through a quantum impurity (quantum dot or molecule) attached to ferromagnetic leads by using a hybrid numerical renormalization group-time-dependent density matrix renormalization group thermofield quench approach.For this, we study the bias dependence of the differential conductance through the system, which shows a finite zero-bias peak, characteristic of the Kondo resonance and reminiscent of the equilibrium local density of states. In the non-equilibrium settings, the resonance in the differential conductance is also found to decrease with increasing the lead spin polarization. The latter induces an effective exchange field that lifts the spin degeneracy of the dot level. Therefore as we demonstrate, the Kondo resonance can be restored by counteracting the exchange field with a finite external magnetic field applied to the system. Finally, we investigate the influence of temperature on the nonequilibrium conductance, focusing on the split Kondo resonance. Our work thus provides an accurate quantitative description of the spin-resolved transport properties relevant for quantum dots and molecules embedded in magnetic tunnel junctions.

Nanometric Moiré Stripes on the Surface of Bi2Se3 Topological Insulator.

Mismatch between adjacent atomic layers in low-dimensional materials, generating moiré patterns, has recently emerged as a suitable method to tune electronic properties by inducing strong electron correlations and generating novel phenomena. Beyond graphene, van der Waals structures such as three-dimensional (3D) topological insulators (TIs) appear as ideal candidates for the study of these phenomena due to the weak coupling between layers. Here we discover and investigate the origin of 1D moiré stripes on the surface of Bi2Se3 TI thin films and nanobelts. Scanning tunneling microscopy and high-resolution transmission electron microscopy reveal a unidirectional strained top layer, in the range 14–25%, with respect to the relaxed bulk structure, which cannot be ascribed to the mismatch with the substrate lattice but rather to strain induced by a specific growth mechanism. The 1D stripes are characterized by a spatial modulation of the local density of states, which is strongly enhanced compared to the bulk system. Density functional theory calculations confirm the experimental findings, showing that the TI surface Dirac cone is preserved in the 1D moiré stripes, as expected from the topology, though with a heavily renormalized Fermi velocity that also changes between the top and valley of the stripes. The strongly enhanced density of surface states in the TI 1D moiré superstructure can be instrumental in promoting strong correlations in the topological surface states, which can be responsible for surface magnetism and topological superconductivity.

Manipulating generalized Dirac cones in subwavelength dipolar arrays

We discuss the emergence and manipulation of generalized Dirac cones in the subradiant collective modes of a subwavelength dipolar array. We consider a collection of single quantum emitters modeled as point dipoles arranged in a honeycomb lattice with subwavelength periodicity. While conventional honeycomb arrays host bound modes that display Dirac cones at the $K$ and ${K}^{\ensuremath{'}}$ points, we show that introducing uniaxial anisotropy in the lattice results in modified dispersion relations. These include the tilting of Dirac cones arising purely due to long-range, retarded, electromagnetic coupling in the lattice, which changes the local density of states at the Dirac point from vanishing (type I) to diverging (types II and III), the emergence of semi-Dirac points, with linear and quadratic dispersions in orthogonal directions, and the anisotropic movement of Dirac cones away from the $K$ and ${K}^{\ensuremath{'}}$ points. Such energy dispersions can modify substantially the dynamics of local probes, such as quantum emitters, for which they have been shown to induce anisotropic power-law interactions.

P-type ohmic contacts of MBenes with MoS2 for nanodevices and logic circuits

Based on first-principles calculations and quantum transport simulations, we systematically investigate the possibility of using two-dimensional transition metal borides (MBenes) as electrodes for two-dimensional monolayer MoS2 via interfacial interactions, band bending, vertical Schottky barrier, tunneling probability, and lateral Schottky barrier. The weak interaction between the functionalized MBenes and MoS2 results in MoS2 retaining its original intrinsic properties while significantly reducing the Fermi level pinning effect; this, is perfectly consistent with the revised Schottky–Mott model after considering charge redistribution. Combined with band calculations and device local projection density of states, MoS2/TiBO, MoS2/TiBF, and MoS2/MoBO, either with the vertical hole Schottky barrier or the lateral hole Schottky barrier, are negative, forming p-type ohmic contacts. Our work provides theoretical guidance for constructing high-performance nanodevices and MoS2-based logic circuits for large-scale integrated circuits. We demonstrate the outstanding potential of MBenes as electrodes for nanodevices.

Vortex bound states influenced by the Fermi surface anisotropy

The spatial distribution of vortex bound states is often anisotropic, which is correlated with the underlying property of materials. In this work, we examine the effects of Fermi surface anisotropy on vortex bound states. The large-scale calculation of vortex bound states is introduced in the presence of fourfold or twofold Fermi surface by solving the Bogoliubov–de Gennes (BdG) equations. Two kinds of quasiparticles' behaviors can be extracted from the local density of states (LDOS) around a vortex. The angle-dependent quasiparticles will move from high energy to low energy when the angle varies from curvature maxima to minima of the Fermi surface, while the angle-independent quasiparticles tend to stay at a relatively higher energy. In addition, the weight of angle-dependent quasiparticles can be enhanced by the increasing anisotropy degree of Fermi surface.

Heterogeneous nucleation interface between LaAlO3 and niobium carbide: First-principles calculation

This paper aimed to investigate the interface relationship between LaAlO3 and niobium carbide and possibility of LaAlO3 as heterogeneous nucleus to refine niobium carbide by first principles method. Niobium carbide (NbC) is a transition metal carbide with high hardness. Primarily, the lattice mismatch relationship of LaAlO3/NbC was calculated. Then, the interface models were established for the calculation of adhesive work and interface energy of LaAlO3/NbC. Finally, the interfacial bonding types were analyzed with charge density, electron localized function (ELF) and partial density of states (PDOS). The results indicate that the interface mismatch between LaAlO3(001) plane and NbC(111) plane is the smallest (8.4%), which indicates that LaAlO3 can be as a moderately heterogeneous nucleus of NbC. Four interfacial models of LaAlO3(110)/NbC(111) interface were established, which are named as LaAlO-NbT interface, LaAlO-CT interface, OT-NbT interface and OT-CT interface. The adhesive work of the OT-NbT interface is the largest (0.60 J/m2) and its interface energy is the smallest (4.02 J/m2), which indicates that the binding adhesive ability of the OT-NbT interface is the strongest. The bonding types of the OT-NbT interface are the combination of metallic, ionic and covalent bonds. Therefore, LaAlO3 can act as the heterogeneous nucleus of NbC and refine it.

Carcinogenic Heavy Metals Detection Based on ZnO Nanoribbons

The theoretical investigation of zigzag ZnONRs for the detection of carcinogenic heavy metal atoms is reported in the current manuscript. The sensing characteristics of the ZnONRs towards toxic heavy metal atoms are examined by deploying the density functional theory (DFT) calculations together with non-equilibrium Green’s function (NEGF). The variation in the structural, electronic, and transport properties of the ZnONRs post passivation with heavy metal atoms at the edges are considered for the detection. Pristine ZnONR is a semiconductor with an energy bandgap of 0.49 eV and the ZnONRs become metallic after exposure to heavy metal atoms. The quantum transport calculations reveal the enhanced current conductivity in the heavy metal atom exposed ZnONR devices relative to the pristine ZnONR due to the induced metallicity. The local device density of states (LDOS) calculations reveal the major transmission of the carriers occurs through the edges. The ZnONR devices are highly sensitive to Sb and As as compared to the Pb atom. The ZnONR exhibit the highest sensitivity towards the Sb atoms with the sensor response around 3.57 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times \,\,{10}^{{7}}$ </tex-math></inline-formula> %. The sensor sensitivity towards the As and Pb is slightly lower with the sensor responses measured to be 3.52 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times \,\,10^{{7}}$ </tex-math></inline-formula> % and 2.86 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times \,\,10^{{7}}$ </tex-math></inline-formula> %, respectively. Further, FET devices exhibit high sensitivity at zero gate bias voltage of the order of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{10}}$ </tex-math></inline-formula> for Sb-ZnO-Sb, As-ZnO-As, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{9}}$ </tex-math></inline-formula> for Pb-ZnO-Pb devices. The obtained findings suggest that ZnONRs can effectively be used for the detection of carcinogenic heavy metal atoms.

Two-dimensional SiC Schottky junctions with symmetrical and asymmetrical metal electrode contacts

Four symmetrical and six asymmetrical Schottky contacts in the metal–semiconductor-metal structures were constructed by using two-dimensional (2D) SiC material as channel and four metal materials (Ag, Al, Au, Pd) as electrodes. On the basis of density functional theory and ab initio calculation method, devices’ transmission spectra, current–voltage characteristics, local density of states, rectification ratio, current–temperature characteristics and negative differential thermoelectric resistance were studied. The results show that Schottky contact is formed between the four metal materials and the 2D SiC. Partially asymmetrical metal electrode structure devices have excellent rectification characteristics. The device has the optimal rectification characteristics with a rectification ratio of 747 when Pd and Au are used as asymmetrical electrodes. Moreover, the temperature dependence of thermionic excitation transport has a key influence on the rectification properties of the device. The rectification ratio reaches to 2100 around 200 K in the junction of Pd–SiC–Au. A key finding is that the negative differential thermoelectric resistance can be generated in Pd–SiC–Au device when a temperature difference applied between two electrodes without external bias voltage. The results of this study can provide theoretical reference for the subsequent design of transistors and other device based on 2D SiC material.

Exploration of two surfaces observed in Weyl semimetal BaMnSb2

Single crystalline BaMnSb2 is considered as a 3D Weyl semimetal with the 2D electronic structure containing Dirac cones from the Sb sheet. We report experimental investigation of low-temperature cleaved BaMnSb2 surfaces using scanning tunneling microscopy/spectroscopy and low energy electron diffraction. By natural cleavage, we find two terminations: one is Ba (above the orthorhombically distorted Sb sheet) and another Sb2 (at the surface of the Sb/Mn/Sb sandwich layer). Both terminations show the 2 × 1 surface reconstructions, with drastically different morphologies and electronic properties, however. The reconstructed structures, defect types and nature of the electronic structures of the two terminations are extensively studied. The quasiparticle interference (QPI) analysis is conducted at the energy range between −2 V and 2 V, although no interesting states are observed near the Fermi level, the surface-projected electronic band structures strongly depend on the surface termination above 1.6 V. The existence of defects can greatly modify the local density of states to create electronic phase separations on the surface in the order of tens of nm scale. Our observation on the atomic structures of the terminations and the corresponding electronic structures provides critical information towards an understanding of topological properties of BaMnSb2.

Sensitivity of (multi)fractal eigenstates to a perturbation of the Hamiltonian

We study the response of an isolated quantum system governed by the Hamiltonian drawn from the Gaussian Rosenzweig-Porter random matrix ensemble to a perturbation controlled by a small parameter. We focus on the density of states, local density of states and the eigenfunction amplitude overlap correlation functions which are calculated exactly using the mapping to the supersymmetric nonlinear sigma model. We show that the susceptibility of eigenfunction fidelity to the parameter of perturbation can be expressed in terms of these correlation functions and is strongly peaked at the localization transition: It is independent of the effective disorder strength in the ergodic phase, grows exponentially with increasing disorder in the fractal phase and decreases exponentially in the localized phase. As a function of the matrix size, the fidelity susceptibility remains constant in the ergodic phase and increases in the fractal and in the localized phases at modestly strong disorder. We show that there is a critical disorder strength inside the insulating phase such that for disorder stronger than the critical the fidelity susceptibility decreases with increasing the system size. The overall behavior is very similar to the one observed numerically in a recent work by Sels and Polkovnikov [Phys. Rev. E 104, 054105 (2021)] for the normalized fidelity susceptibility in a disordered XXZ spin chain.

New insights into the mechanical and thermal properties of UN1-xCx from first-principles calculations

Uranium nitride (UN) is considered to be a very promising candidate of accident-tolerant fuel. Since UN is commercially synthesized by carbothermic reduction-nitridation, the carbon in synthesized UN is unavoidable. Interestingly, UN1-xCx solid solutions obtained by isothermal conversion exhibit some more excellent properties, such as corrosion resistance. But the effect of composition on the mechanical and thermal properties is not clear yet. In this work, first-principles calculations were carried out to investigate the stabilities, mechanical and thermal properties of UN1-xCx (x = 0.00, 0.25, 0.50, 0.75 and 1.00). The impact of the on-site Coulomb repulsion term and spin-orbit coupling (SOC) on the properties of UN1-xCx were also discussed. The on-site Coulomb repulsion term is indispensable for the magnetic ground state, mechanical and thermal transport properties. Moreover, SOC has a negligible influence on the mechanical properties and can overestimate the thermal conductivities of UN1-xCx. Formation enthalpy, phonon dispersion and elastic constants calculations were preformed to prove the thermodynamic, dynamic and mechanical stability of UN1-xCx, respectively. The absence of a band gap in the density of states confirms the metallic nature of studied UN1-xCx. Theoretical analyses show that large-size carbon doping can induce lattice expansion and softening, resulting in the reduction of elastic moduli. The more localized density of states of UN1-xCx with carbon concentration demonstrate the weaker bond strength, which further verifies the variation of mechanical properties. The thermal conductivities of UN1-xCx calculated using PBE+U decrease firstly, then increase with the carbon concentration and increase with the temperature.

Super‐Resolution Lifetime Imaging of Single Molecules Near Gold Bowtie Nanoparticles

AbstractInteractions between light and matter serve as the basis of many technologies, but the quality of these devices is inherently limited by the optical properties of their constituents. Plasmonic nanoparticles are a highly versatile and tunable platform for the enhancement of such optical properties. However, the near‐field nature of these effects has made thorough study and understanding of these mechanisms difficult. In this work, we introduce a fully confocal technique combining photoswitching super‐resolution microscopy with fluorescence lifetime imaging microscopy to study single‐molecule decay rate enhancement. We demonstrate that the technique combines a spatial resolution better than 20 nm, and a 16 ps temporal resolution. Simultaneously, an autocorrelation measurement is also performed to confirm that the data indeed originates from single molecules. This work provides insight into the various mechanisms of plasmon‐enhanced emission, and allows the study of the correlation between emission intensity and lifetime enhancement. This complicated relationship is shown to be dependent upon the relative influence of various radiative and nonradiative decay pathways. Here, we provide a platform for further study of emission mislocalization, the position‐dependent prominence of different decay pathways, and the direct super‐resolved measurement of the local density of states.

Hopping or Tunneling? Tailoring the Electron Transport Mechanisms through Hydrogen Bonding Geometry in the Boron-Doped Diamond Molecular Junctions.

Mechanisms of charge transport in molecular junctions involving hydrogen bonds are complex and remain mostly unclear. This study is focused on the elucidation of the electron transfer in a molecular device consisting of two boron-doped diamond interfaces bound with an aromatic linker and a hydrogen bonding surrogating molecule. The projected local density of states (PLODS) analysis coupled with transmission spectra and current–voltage (I–V) simulations show that hydrogen bonding through electron-donating hydroxyl groups in the aromatic linker facilitates electron transfer, while the electron-withdrawing carboxyl group inhibits electron transfer across the junction. Moreover, slight variations in the geometry of hydrogen bonding lead to significant changes in the alignment of the energy levels and positions of the transmission modes. As a result, we observe the switching of the electron transport mechanism from tunneling to hopping accompanied by a change in the shape of the I–V curves and current magnitudes. These results give important information on the tailoring of the electronic properties of molecular junctions.

Geometry-induced wave-function collapse

When a quantum particle moves in a curved space, a geometric potential can arise. In spite of a long history of extensive theoretical studies, to experimentally observe the geometric potential remains a challenge. What are the physically observable consequences of such a geometric potential? Solving the Schr\"odinger equation on a truncated conic surface, we uncover a class of quantum scattering states that bear a strong resemblance to the quasiresonant states associated with atomic collapse about a Coulomb impurity, a remarkable quantum phenomenon in which an infinite number of quasiresonant states emerge. A characteristic defining feature of such collapse states is the infinite oscillations of the local density of states (LDOS) about the zero energy point separating the scattering from the bound states. The emergence of such states in the curved (Riemannian) space requires neither a relativistic quantum mechanism nor any Coulomb impurity: they have zero angular momentum and their origin is purely geometrical, hence the term ``geometry-induced wave-function collapse.'' We establish the collapsing nature of these states through a detailed comparative analysis of the behavior of the LDOS for both the zero and finite angular momentum states as well as the corresponding classical picture. Potential experimental schemes to realize the geometry-induced collapse states are articulated. Not only does our paper uncover an intrinsic connection between the geometric potential and atomic collapse, it also provides a method to experimentally observe and characterize geometric potentials arising from different subfields of physics. For example, in nanoscience and nanotechnology, curved geometry has become increasingly common. Our finding suggests that wave-function collapse should be an important factor of consideration in designing and developing nanodevices.

Crossed Andreev reflection in spin-polarized chiral edge states due to the Meissner effect

We consider a hybrid quantum Hall-superconductor system, where a superconducting finger with oblique profile is wedged into a two-dimensional electron gas in the presence of a perpendicular magnetic field, as considered by Lee et al., Nat. Phys. 13, 693 (2017). The electron gas is in the quantum Hall regime at filling factor $\ensuremath{\nu}=1$. Due to the Meissner effect, the perpendicular magnetic field close to the quantum Hall-superconductor boundary is distorted and gives rise to an in-plane component of the magnetic field. This component enables nonlocal crossed Andreev reflection between the spin-polarized chiral edge states running on opposite sides of the superconducting finger, thus opening a gap in the spectrum of the edge states without the need of spin-orbit interaction or nontrivial magnetic textures. We compute numerically the transport properties of this setup and show that a negative resistance exists as a consequence of nonlocal Andreev processes. We also obtain numerically the zero-energy local density of states, which systematically shows peaks stable to disorder. The latter result is compatible with the emergence of Majorana bound states.