Conductance Peak Research Articles

Ohmic heating in the upper atmosphere of hot exoplanets. The influence of a time-varying magnetic field

Exoplanets on close-in orbits are subject to intense X-ray and ultraviolet (XUV) irradiation from their star. Their atmosphere heats up, sometimes to the point where it will thermally escape from the gravitational potential of the planet. Nonetheless, XUV is not the only source of heating in such atmospheres. Indeed, close-in exoplanets are embedded in a medium (the stellar wind) with strong magnetic fields that can significantly vary along the orbit. Variations in this magnetic field can induce currents in the upper atmosphere, which dissipate and locally heat it up through Ohmic heating. The aim of this work is to quantify Ohmic heating in the upper atmosphere of hot exoplanets, due to an external time-varying magnetic field, and to compare it to the XUV heating. Ohmic heating depends strongly on the conductivity properties of the upper atmosphere. We developed a 1D formalism to assess the level and the localization of Ohmic heating depending on the conductivity profile. The formalism is applied to the specific cases of Trappist-1 b and π Men c. Ohmic heating can reach values up to 10^-3 erg s^-1 cm^-3 in the upper atmospheres of hot exoplanets. It is expected to be stronger the closer the planet and the lower its central star mass, as these conditions maximize the strength of the ambient magnetic field around the planet. The location of maximal heating depends on the conductivity profile (but does not necessarily occurs at the peak of conductivity) and, in particular, on the existence and strength of a steady planetary field. Such extra heating can play a role in the thermal budget of the escaping atmosphere when the planetary atmospheric magnetic fields is between 0.01 G and 1G. We confirm that Ohmic heating can play an important role in setting the thermal budget of the upper atmosphere of hot exoplanets and can even surpass the XUV heating in the most favorable cases. When it is strong, a corollary is that the upper atmosphere screens efficiently time-varying external magnetic fields, preventing them from penetrating deeper in the atmosphere or even within the planet itself. We find that both Trappist-1b and π Men c are likely being subjected to intense Ohmic heating.

Critical Lengths of Kitaev Chains for Majorana Zero Modes with a Microsecond Coherence Time and a Quantized Conductance Signature.

The problems of disorder and insufficient system length are generally regarded as central problems in the realization of Majorana zero modes (MZM), which are a promising platform for realizing fault-tolerant topological quantum computing (TQC). In this work, we analyze eigenenergy spectra and transport properties of finite Kitaev chains using quantum transport simulations in a wide design space of hopping amplitude (t), superconductor pairing (Δ), and electrochemical potential. Our goal is to determine critical or minimum acceptable chain lengths to obtain oscillation-free MZMs with suitable microsecond coherence times, and observable zero-bias conductance peaks (ZBCP) quantized almost at ~2e2/h. Due to qualitative equivalence of the Kitaev and Oreg-Lutchyn models, we approximately determine the foreseeable critical length of topological superconducting nanowires (TS NWs) as well. We find that the ZBCP length requirement is looser in comparison to the limit imposed by the coherence time. For a large t/Δ mismatch of ~40 corresponding to the experimental TS NWs, the first condition sets the minimum length to 344 sites (≈5.5 μm), while the second condition requires 605 sites (≈9.7 μm). The calculated lengths are far from the reported experimental hybrid device dimensions, explaining difficulties in observing MZMs in TS NWs fabricated so far. Nonetheless, a decreasing t/Δ mismatch allows for shorter systems, which argues in favor of the proximitized quantum dot path for MZMs in a solid-state system.

New regime of the Coulomb blockade in quantum dots

We consider how the absence of thermalization affects the classical Coulomb blockade regime in quantum dots. By solving the quantum kinetic equation in the experimentally accessible regime when the dot has two relevant occupation states, we calculate the current–voltage characteristics for arbitrary coupling to the leads. If the couplings are strongly asymmetric, the Coulomb staircase is practically reduced to the first step, which is independent of the charging energy, when the Fermi energy is comparatively small, while the standard thermalized results are recovered in the opposite case. When the couplings are of the same order, the absence of thermalization has a new, striking signature—a robust additional peak in the differential conductance.

Observation of Yu-Shiba-Rusinov-like states at the edge of CrBr3/NbSe2 heterostructure

The hybrid ferromagnet-superconductor heterostructures have attracted extensive attention as they potentially host topological superconductivity. Relevant experimental signatures have recently been reported in CrBr3/NbSe2 ferromagnet-superconductor heterostructure, but controversies remain. Here, we reinvestigate CrBr3/NbSe2 by an ultralow temperature scanning tunneling microscope with higher spatial and energy resolutions. We find that the single-layer CrBr3 film is insulating and acts likely as a vacuum barrier, the measured superconducting gap and vortex state on it are nearly the same as those of NbSe2 substrate. Meanwhile, in-gap features are observed at the edges of CrBr3 island, which display either a zero-energy conductance peak or a pair of particle-hole symmetric bound states. They are discretely distributed at the edges of CrBr3 film, and their appearance is found closely related to the atomic lattice reconstruction near the edges. By increasing tunneling transmissivity, the zero-energy conductance peak quickly splits, while the pair of nonzero in-gap bound states first approach each other, merge, and then split again. These behaviors are unexpected for Majorana edge modes, but in consistent with the conventional Yu-Shiba-Rusinov states. Our results provide critical information for further understanding the interfacial coupling in CrBr3/NbSe2 heterostructure.

Tuning band gap and improving optoelectronic properties of lead-free halide perovskites FrMI3 (M = Ge, Sn) under hydrostatic pressure

In the field of optoelectronic applications, inorganic cubic halide perovskites have turned into a leading choice for commercialization. The physical properties of cubic FrMI3 (M = Ge, Sn) halide perovskites under pressure are explored at multiple pressures up to 10 GPa using ab initio Density-Functional Theory due to their significant importance. The structural accuracy, reflected in lattice parameters and unit cell volume, closely corresponds to previously reported data. FrGeI3 and FrSnI3 exhibited direct electronic band gaps of 0.65 eV and 0.46 eV with GGA-PBE functional, respectively, indicating their semiconducting nature at 0 GPa. The enhanced band gaps obtained employing the HSE06 potential are 1.61 eV and 1.28 eV for the corresponding perovskites. FrGeI3 and FrSnI3 shift from semiconducting to metallic states under pressures of 4.5 GPa and 3 GPa, respectively, thereby enhancing the conductivity. Pressure also improves optical functions, indicating both perovskites may be employed in high-efficiency optoelectronic devices that operate within the visible and ultra-violet (UV) range. At 10 GPa pressure, both FrGeI3 and FrSnI3 demonstrate the sharpest absorption spikes in the UV region, approximately at 2.61 × 105 cm−1 and 2.42 × 105 cm−1, respectively, resulting in sharp peaks in optical conductivity of approximately 5.98 1/fs for FrGeI3 and 5.49 1/fs for FrSnI3. FrGeI3 consistently outperforms FrSnI3, offering superior electronic and optical characteristics. Additionally, pressure modifies the mechanical features of entitled perovskites while conserving stability. The anisotropic and ductile properties become more pronounced under pressure. The outcomes of this study are expected to propel the advancement of lead-free optoelectronic devices, driving innovation in sustainable energy solutions.

Perspective on Majorana bound-states in hybrid superconductor-semiconductor nanowires

A personal perspective is given on a decade of research on Majorana bound states (MBS) in hybrid devices of semiconducting nanowires covered with a superconductor. Predicted experimental signatures like zero-bias anomalies turned out to be false positive evidence for topological MBS. Zero-bias conductance peaks have found alternative explanations in terms of material disorder and smooth boundary potentials. A recount is given on various predictions, observations and re-interpretations, as well as the lessons learned in retrospect and an outlook on the future.

High entropy alloy particle reinforced 6061 aluminum matrix composites: An investigation of mechanical strength and thermoelectric properties

The relentless pursuit of advanced materials characterized by superior mechanical and thermoelectric properties has spurred significant research into metal matrix composites (MMCs), particularly aluminum matrix composites (AMCs). This study investigates the development of 6061 aluminum alloy composites reinforced with varying concentrations (4–10 wt%) of AlCoCrFeNi high-entropy alloy (HEA) particles via Spark Plasma Sintering (SPS). Key findings underscore the positive impact of HEA reinforcement on the density and hardness of AMCs, while revealing a complex relationship between HEA content and strength. The composite incorporating 6 wt% HEA exhibited optimal properties, characterized by a density of 2.85 g/cm³, Vickers hardness of 85 HV, ultimate tensile strength of 174 MPa, and elongation of 13.7 %. A corresponding peak in thermal conductivity was observed at this composition, while electrical conductivity diminished due to increased phonon scattering.

Light-modulated 8-Pmmn borophene-based pure crossed Andreev reflection

Abstract We investigate the off-resonant circularly polarized light-modulated crossed Andreev reflection in an 8-Pmmn borophene-based normal conductor/superconductor/normal conductor junction. When the signs of Fermi energies in two normal regions are opposite, the pure crossed Andreev reflection without the local Andreev reflection and the elastic cotunneling occurs. By using the Dirac-Bogoliubov-de Gennes equation and the Blonder-Tinkham-Klapwijk formula, the pure crossed Andreev reflection conductance and its oscillation as a function of the junction length and the Fermi energy in the superconducting regions are discussed. It is found that the value of pure crossed Andreev reflection conductance peak value and its corresponding value of light-induced gap increase with the increase of incident energy of electron. Furthermore, the valley splitting for the transmitted hole is found due to the presence of tilted velocity of borophene. Our findings are beneficial for designing the high efficiency 8-Pmmn borophene-based nonlocal transistor and nonlocal valley splitter without local and non-entangled processes.

Label-Free Single-Molecule Electrical Sensor for Ultrasensitive and Selective Detection of Iodide Ions in Human Urine.

Herein, a label-free single-molecule electrical sensor was first proposed for the ultrasensitive and selective detection of iodide ions in human urine. Single-molecule conductance measurements in different halogen ion solutions via scanning tunneling microscopy break junction (STM-BJ) clearly revealed that I- ions strongly affect the stability and displacement distance (Δz) distribution of molecular junctions. Theoretical calculations prove that the specific adsorption of I- ions modifies the surface properties and weakens the molecular adsorption. Furthermore, the average conductance peak area versus the logarithm of the I- ion concentration has a very good linear relationship in the range of 5 × 10-6 to 5 × 10-10 M, with a correlation coefficient of 0.99. This quantitative analysis remains valid in the presence of interfering ions of SO42-, ClO4-, Br-, and Cl- as well as interfering molecules of ascorbic acid, uric acid, dopamine, and cysteine. A cross-comparison of the human urine detection results of this single-molecule electrical sensor with those of the clinical method of As3+-Ce4+ catalytic spectrophotometry revealed an average difference of 0.9%, which decreased the detection time of 2 h with the traditional method to approximately 15 min. This work proves the promising practical potential of the single-molecule electrical technique for relevant clinical analysis.

Autonomous nervous system responses to environmental-level exposure to 5G's first deployed band (3.5GHz) in healthy human volunteers.

Following the global progressive deployment of 5G networks, considerable attention has focused on assessing their potential impact on human health. This study aims to investigate autonomous nervous system changes by exploring skin temperature and electrodermal activity (EDA) among 44 healthy young individuals of both sexes during and after exposure to 3.5GHz antenna-emitted signals, with an electrical field intensity ranging from 1 to 2V/m. The study employed a randomized, cross-over design with triple-blinding, encompassing both 'real' and 'sham' exposure sessions, separated by a maximum interval of 1week. Each session comprised baseline, exposure and postexposure phases, resulting in the acquisition of seven runs. Each run initiated with a 150s segment of EDA recordings stimulated by 10 repeated beeps. Subsequently, the collected data underwent continuous decomposition analysis, generating specific indicators assessed alongside standard metrics such as trough-to-peak measurements, global skin conductance and maximum positive peak deflection. Additionally, non-invasive, real-time skin temperature measurements were conducted to evaluate specific anatomical points (hand, head and neck). The study suggests that exposure to 3.5GHz signals may potentially affect head and neck temperature, indicating a slight increase in this parameter. Furthermore, there was a minimal modulation of certain electrodermal metrics after the exposure, suggesting a potentially faster physiological response to auditory stimulation. However, while the results are significant, they remain within the normal physiological range and could be a consequence of an uncontrolled variable. Given the preliminary nature of this pilot study, further research is needed to confirm the effects of 5G exposure.

Buckling strain effects on the electron and the phonon spectra, the stability, thermal, and optical characteristics of an MgO nanosheet using PBE/GGA and HSE06

The stability, the electronic, the phonon, the thermal, and the optical properties of a buckled MgO monolayer are investigated using DFT with the PBE/GGA and the HSE06 functionals. Model calculations for a buckled MgO monolayer indicate a more interesting behavior than for its flat phase. The band gap decreases from 4.9 to 2.83 eV within the HSE06 approach due to increased electron density of states in the conduction band in the direction of the buckling. Both phonon dispersion and molecular dynamic calculations confirm the dynamic and the thermal stability of the buckled MgO monolayer. The heat capacity of a buckled monolayer is higher than for the flat one in a high temperature range due to a higher phonon density of states caused by the buckling effects. Furthermore, the buckled MgO monolayer has a higher static dielectric function leading to an increased ability to store electrical energy. The buckling creates wrinkles at the surface of the MgO monolayer that can localize collective electron oscillations, resulting in suppression of the plasmon frequency. The main intensity peak in the optical conductivity is red-shifted from the near-ultraviolet to the visible light region in the presence of buckling which may be beneficial for optoelectronic devices.

Fabrication and Characterization of Alkyl-Functionalized CNFs/Cellulose Acetate Polymer Nanocomposites

Carbon nanofibers (CNFs) are kwidely used to fabricate nanocomposites with enhanced properties. The emergent properties of the nanocomposites depend on the initial properties of the CNFs and how the fibers have been dispersed within the polymer matrix. This study looks at the fabrication of nanocomposites using dodecyl, butyl, and acetyl functionalized CNFs with cellulose acetate as the polymer matrix. The CNFs were prepared by electro-spinning, and functionalization was achieved using alkyl halides in the presence of lithium. Scanning Electron Microscopy (SEM) showed that the fibers were well embedded in the polymer Matrix, Thermal Gravimetric Analysis (TGA) of the nanocomposite revealed a slight increase in the degradation temperatures of the nanocomposites as compared to the blank sample, the aggregate loss of weight of the samples was about 80%. Dynamic Mechanical Analysis (DMA) of the nanocomposites showed increased stiffness and modulus storage by an average of 450MPa for butyl and dodecyl-functionalized CNFs, however, the storage modulus values of the nanocomposites generally decreased with an increase in temperature. The glass transition temperature of the nanocomposites was higher than that of the reference sample by an average of +36°C. Conductivity measurements of the nanocomposites showed no changes at lower frequencies of 1x10<sup>2</sup> - 4x10<sup>4</sup>Hz. However, the values started increasing at peaked at 5x10<sup>7</sup>Hz. The conductivity measurements revealed that the nanocomposites exhibited higher conductivity peaks at specific frequencies compared to the reference sample, indicating an enhanced electrical property of the nanocomposite. The study successfully fabricated nanocomposites with enhanced mechanical, thermal, and dielectric properties using functionalized CNFs.

Corrosion evolution and quantitative corrosion monitoring of Q355 steel for offshore wind turbines in multiple marine corrosion zones

Offshore wind turbines operating in harsh marine environments are at risk of corrosion. Thickness loss and perforation caused by corrosion can lead to component failure or structure collapse. An environmental test setup was constructed to simulate various marine corrosion zones. Several experimental studies were conducted on Q355 steel, commonly used in offshore wind turbines. The mass loss and electrochemical properties of the steel specimens were analyzed, including electrochemical impedance spectra and polarization curves. The results indicate that corrosion remains stable in the immersion and tidal zones, whereas corrosion in the splash zone is the most severe, with a corrosion rate as high as 0.70 mm/a. A significant macroscopic corrosion cell effect was observed on the vertical steel strip, accelerating corrosion in the splash zone and at the low tide line. The corrosion product compositions and corrosion morphology of each corrosion zone were characterized and analyzed. Furthermore, a corrosion monitoring sensor based on electromechanical impedance was proposed. A prediction model for the mass loss rate of vertical steel strips was developed based on the conductance peak frequency. This study elucidates the corrosion evolution of wind turbine structural steel and proposes a comprehensive steel corrosion monitoring solution.

Influence of pressure on the different physical features of lead-free double perovskite materials K2SnX6 (X = Cl, and Br): DFT replication

The influence of pressure (0–12 GPa) on several physical features of perovskite materials K2SnX6 (X = Cl, and Br) has been executed through DFT replication coded with CASTEP. Very close relation is noticed concerning the studied and synthesized lattice parameters. The studied compounds are mechanically stable under pressure according to Born's stability criteria. The Pugh's and Poisson's ratios indicate the brittle nature K2SnCl6 at 0 GPa and ductile nature at above 2 GPa. On the other hand, the phase K2SnBr6 exhibits ductile in nature at 0 GPa to high pressure. The increasing behaviors of machinable index with increasing pressure making these materials effectively useable in industrial applications. The determined Vickers hardness (Hv) values at several pressures of both the phases did not exceed 8 GPa which enables them to be more machinable and damage-tolerant. The decrease of band gap with increasing pressure ensures the probable application of these materials in optoelectronic devices. The bond length decreases with increasing pressure and consequently materials become harder. As the static dielectric constant of K2SnBr6 is higher than K2SnCl6, hence K2SnBr6 is more suitable for optoelectronic device applications. In the ultraviolet region, both the materials show their intense peak of absorption and conductivity. Both the studied compounds processes very low thermal conductivity in the entire pressure ranges comparing to the well-known thermal barrier coating (TBC) materials ABO3 which confirming their better uses in industry as TBC materials. Having very high melting temperature at high pressure these compounds are suitable for high-temperature application purposes.

Non-Hermitian zero-energy pinning of Andreev and Majorana bound states in superconductor-semiconductor systems

The emergence of Majorana bound states in finite length superconductor-semiconductor hybrid systems has been predicted to occur in the form of oscillatory energy levels with parity crossings around zero energy. Each zero-energy crossing is expected to produce a quantized zero-bias conductance peak but several studies have reported conductance peaks pinned at zero energy over a range of Zeeman fields, whose origin, however, is not clear. In this work, we consider superconducting systems with spin-orbit coupling under a Zeeman field and demonstrate that non-Hermitian effects, due to coupling to ferromagnet leads, induce zero-energy pinning of Majorana and trivial Andreev bound states. We find that this zero-energy pinning effect occurs due to the formation of non-Hermitian spectral degeneracies known as exceptional points, whose emergence can be controlled by the interplay of non-Hermiticity, the applied Zeeman field, and chemical potentials. Moreover, depending on the non-Hermitian spatial profile, we find that non-Hermiticity changes the single point Hermitian topological phase transition into a flattened zero energy line bounded by exceptional points from multiple low energy levels. This seemingly innocent change notably enables a gap closing well below the Hermitian topological phase transition, which can be in principle simpler to achieve. Furthermore, we reveal that the energy gaps separating Majorana and trivial Andreev bound states from the quasicontinuum remain robust for the values that give rise to the zero-energy pinning effect. While reasonable values of non-Hermiticity can be indeed beneficial, very strong non-Hermitian effects can be detrimental as it might destroy superconductivity. Our findings can be therefore useful for understanding the zero-energy pinning of trivial and topological states in Majorana devices. Published by the American Physical Society 2024

Theoretical study of optoelectronic, elastic and mechanical properties of gallium modified barium titanate (Ba1-xGaxTiO3) perovskite ceramics by DFT

In this report, we study the gallium modified Barium titanate (Ga-BTO) Ba1-xGaxTiO3 with (x = 50 %) perovskite ceramics, which have not been synthesized experimentally to date. The density functional theory-based full potential linear augmented plane wave has been employed to determine the optoelectronic, elastic, and mechanical properties of pure and modified BaTiO3. Completely relaxed 2 × 2× 2 of primitive five atoms’ cells has been used for calculations. A large cut-off energy of 120 Ry has been used to eliminate the basics of plane wave-indicating wave functions. The influence of substitution of Ga on electronic structure and optical parameters such as reflectivity, refractivity, dielectric function, optical conductivity, extinction, and absorption coefficients are analyzed and elucidated with TDOS and PDOS. The Ga modified BTO manifests a forbidden energy gap of 1.84 eV. The static dielectric constant Ɛ1(o) has values of 8.8 and 100 for pure and modified compounds respectively. Ga dopant improved the polarizing power of BTO and for the doped BTO imaginary part, Ɛ2(ω)showed a prominent peak located at 3.9 eV. The optical properties show that perovskite compound substituted with Ga is a good absorber in the ultraviolet region and the modified material has a small value of reflectivity and static refractive index 12.2. The general profiles of optical spectra of modified BaTiO3 display highly desirable features like the prominent peaks of optical conductivity obtained at 4.2 and 5.8 eV for modified BTO that make it a promising candidate for optoelectronic and spintronics. Ga-modified BTO has higher ductility, modulus (169.96 GPa), and anisotropy (2.949) than pure BTO found by analyzing their elastic and mechanical properties.

Revealing the Structural, Electronic, Optical, and Thermoelectric Aspects of the Gold‐Based Double Perovskites X2Au+Au3+Br6 (X = Cs, Rb) Using a First‐Principles Approach

Lead‐free double perovskites are now assumed to be suitable candidates for green energy harvesting in particular as active materials for solar cells and thermoelectric generators, which can meet future generation energy needs. Therefore, we explore the Au‐based halide double perovskites X2Au+Au3+Br6 (X = Cs, Rb) from the first principles approach. Density functional theory (DFT) is utilized to explore the electronic structure with DFT code Quantum ESPRESSO. The mechanical, thermodynamic, and structural stability is ensured from Burn‐Haun criterion, formation energies, and Goldschmidt factors, respectively. The examined materials have stable structures with direct band gaps i.e. 1.54 and 1.72 eV. The existence of band gaps in the visible region motivates us to explore the optical properties, which give fascinating outcomes. The absorption coefficients and optical conductivity peaks are found to be significant in the visible region i.e., ≈104 cm−1 and ≈1015 s−1, respectively. Additionally, the thermoelectric properties are also investigated using Boltzmann transport theory. There are several good gestures for the usage in the thermoelectric generators since the values of Seebeck coefficients (446.5, and 225.2 μV K−1), power factors (1.75 × 1011 W mk−2 s, and 1.24 × 1011 W mk−2 s), and figure of merits (0.92 and 0.73) are noteworthy for Cs2AuAuBr6 and Rb2AuAuBr6, respectively, at room temperature T = 300 K.

Electrochemical Impedance Spectroscopy in the Determination of the Dielectric Properties of Tau-441 Protein for Dielectrophoresis Response Prediction.

This study employs electrochemical impedance spectroscopy (EIS) to probe the behavior of Tau-441 protein, a key component implicated in Alzheimer's disease. Through meticulous experimentation and analysis, the impedance of Tau-441 protein suspension revealed a conductivity peak value of 1.02 S/m. The study demonstrates a high level of specificity and selectivity, particularly within the challenging nanomolar concentration range. Additionally, the EIS method enabled the prediction of Tau-441 protein's dielectrophoresis (DEP) response and the determination of the associated frequency range of 1 kHz to 1 MHz. These findings contribute to advancing our understanding of the molecular intricacies surrounding Tau-441 and hold promise for unraveling implications related to Alzheimer's disease. This study establishes a robust foundation for future research on neurodegenerative disease and biosciences, offering valuable insights into the electrochemical dynamics of Tau-441 protein.

Optical Absorption in Tilted Geometries as an Indirect Measurement of Longitudinal Plasma Waves in Layered Cuprates.

Electromagnetic waves propagating in a layered superconductor with arbitrary momentum, with respect to the main crystallographic directions, exhibit an unavoidable mixing between longitudinal and transverse degrees of freedom. Here we show that this basic physical mechanism explains the emergence of a well-defined absorption peak in the in-plane optical conductivity when light propagates at small tilting angles relative to the stacking direction in layered cuprates. More specifically, we show that this peak, often interpreted as a spurious leakage of the c-axis Josephson plasmon, is instead a signature of the true longitudinal plasma mode occurring at larger momenta. By combining a classical approach based on Maxwell's equations with a full quantum derivation of the plasma modes based on modeling the superconducting phase degrees of freedom, we provide an analytical expression for the absorption peak as a function of the tilting angle and light polarization. We suggest that an all-optical measurement in tilted geometry can be used as an alternative way to access plasma-wave dispersion, usually measured by means of large-momenta scattering techniques like resonant inelastic X-ray scattering (RIXS) or electron energy loss spectroscopy (EELS).

A two-site Kitaev chain in a two-dimensional electron gas.

Artificial Kitaev chains can be used to engineer Majorana bound states (MBSs) in superconductor-semiconductor hybrids1-4. In this work, we realize a two-site Kitaev chain in a two-dimensional electron gas by coupling two quantum dots through a region proximitized by a superconductor. We demonstrate systematic control over inter-dot couplings through in-plane rotations of the magnetic field and via electrostatic gating of the proximitized region. This allows us to tune the system to sweet spots in parameter space, where robust correlated zero-bias conductance peaks are observed in tunnelling spectroscopy. To study the extent of hybridization between localized MBSs, we probe the evolution of the energy spectrum with magnetic field and estimate the Majorana polarization, an important metric for Majorana-based qubits5,6. The implementation of a Kitaev chain on a scalable and flexible two-dimensional platform provides a realistic path towards more advanced experiments that require manipulation and readout of multiple MBSs.