The scalability of self-driving labs is currently limited by the high cost of automated liquid handling. To address this, we present a low-cost, open-source platform designed to function as a 'frugal twin' to serve as a programmable hardware node in automated labs. To do this, we modified a commercial Ender-3 3D printer to print solutions on flexible paper-based substrates using a custom syringe pump assembly. Driven by the printer’s native stepper motor and G-code infrastructure, the system dispenses reagents via disposable pipette tips. Our demonstration with printed dyes shows a reliability of 96.8% and 98.2% for positional accuracy and uniformity of droplet circularity respectively, confirming the system's potential as a standardized and low-cost module for automated research.

Hybrid organic-inorganic perovskites with chiral organic cations are very interesting for optoelectronic applications because of their intrinsically chiral light-matter interactions. Chiral distortions in these materials lead to circular dichroism, circular birefringence, and circularly polarized luminescence in the band transitions of the inorganic sublattice. Raman-active vibrational modes in these crystals are governed by crystal symmetry and therefore are also strongly impacted by the nature and magnitude of the chiral distortions. Here, low-frequency Raman modes that are sensitive to circularly polarized excitation are reported in chiral hybrid organic-inorganic perovskites (CHOIPs) across a wide range of structures and compositions. The circularly polarized Raman spectra from enantiomers of CHOIP single crystals exhibit sharp modes below 150 cm-1, corresponding to vibrations of the lead iodide octahedra. These modes exhibit strong differences in intensities (Raman optical activity, ROA) depending on the handedness of the excitation, with high degree of polarization for several modes. Calculations reveal the presence of several chiral phonon modes with opposite phonon angular momenta. The strong ROA and the chiral phonon modes are a direct consequence of chirality transfer from the chiral organic linker to the lead iodide octahedra in the CHOIP structure, resulting in a strong chiroptical response in the phonon modes.

Single-crystal X-ray diffraction and nonlinear optical measurements, especially second- and third-harmonic generation (SHG/THG) are comprehensively investigated for the van der Waals layered material AgScP2S6 with a non-centrosymmetric P31c (159) space group. Linear optical constants are extracted using spectroscopic ellipsometry and applied in fitting the harmonic generation behavior. Polarization-resolved SHG and THG measurements exhibit pronounced anisotropy, with emission patterns well-described by theoretical models derived from the khi(2) and khi(3) tensor elements. The material demonstrates exceptionally high nonlinear susceptibilities, with khi(2) 10^(-8) m/V and khi(3) 10^(-17) m^2/V^2 which is a few orders of magnitude greater than comparable 2D materials reported in the literature. Temperature-dependent SHG and THG measurements from 300 K to 25 K reveal exponential decay in harmonic signal intensities, attributed to reduced carrier mobility, with no evidence of structural phase transitions, consistent with results from single crystal diffraction and heat capacity measurements. Polarization-resolved SHG and THG measurements also reveal distinct orientation and ellipticity trends, highlighting the anisotropic nonlinear tensor contributions and contrasting polarization selection rules in the material. These results establish AgScP2S6 as a high-performance, thermally stable, and highly anisotropic nonlinear candidate material suitable for compact photonic applications such as ultrafast optical modulators, polarization-sensitive detectors, and wavelength-tunable light sources.

The coexistence of structural anisotropy with building units approaching the atomic scale endows materials with unusual properties. Recently, the class of Chevrel-type chalcogenides consisting of quasi-onedimensional (q-1D) [Mo3Q3] n-(Q = chalcogen) chains intercalated with A + (A = alkali or main group) cations garnered renewed interest for their potential to manifest metallicity, superconductivity, and q-1D Dirac fermionic states. However, understanding their structure and properties is challenging due to their propensity to form polycrystals. Here, we demonstrate the vapor-phase-assisted synthesis of sizable crystals of a q-1D Chevrel-like crystal, In2-delta Mo6Te6, facilitating detailed investigations of its crystal structure and electronic properties. We found from structural characterization and first-principles calculations that the distinct structure, radius ratios, and composition in In2-delta Mo6Te6 impose thermodynamically favored fractional vacancy in approximately one-eighth of In sites. In2-delta Mo6Te6 shows signatures of 1D anisotropy and persistent metallicity down to 1.7 K, despite prevailing notions that q-1D metals undergo Peierls distortion.

We report direct experimental evidence for Anderson localization driven by quantum interference in disordered single-layer graphene induced via controlled Ar+ ion irradiation. By systematically introducing defects and quantifying the disorder using the Raman ID/IG ratio, we map the interdefect distance LD and uncover a critical localization threshold near LD* ≈ 20 nm, where multiple transport and spectroscopic signatures converge. Time-resolved reflectivity measurements reveal a nonmonotonic dependence of the carrier relaxation times τ1,2, peaking at LD*, indicating the emergence of spatially localized states. Tight-binding simulations confirm this threshold as the crossover between delocalized and exponentially localized regimes, satisfying the Ioffe-Regel condition kF l ≈ 1. Electrical resistivity increases exponentially below LD*, while Seebeck coefficients saturate, consistent with hopping-dominated transport. Notably, the power factor S2/ρ and the thermoelectric figure of merit zT exhibit pronounced maxima near LD*, corroborating theoretical predictions that localization can enhance thermoelectric performance by introducing sharp energy filtering at mobility edges. While graphene's intrinsic zT remains low due to high thermal conductivity, these results establish graphene as a model system for probing disorder-driven transport, offering the most direct experimental validation to date of localization-enhanced thermopower in two-dimensional Dirac systems.

Ultraviolet (UV) exciton-polaritons (EPs) enable nonlinear optics, polaritonic lasing, and polariton-mediated photochemistry in the short-wavelength regime, yet progress has been limited due to the scarcity of materials that combine large oscillator strength with stable and narrow UV excitons. Here, we demonstrate UV EPs in silver phenylthiolate (Thiorene, AgSPh), a van der Waals (vdW) layered metal-organic chalcogenolate (MOC) that forms a natural multi-quantum-well (MQW) architecture showing strong excitonic features. Imaging spectroscopic ellipsometry reveals a pronounced in-plane excitonic resonance at 3.46 eV with a narrow linewidth of 60 meV, strong UV birefringence (Δn 0.3), and a high refractive index (n 2.1). Temperature-dependent photoluminescence (PL) shows excitonic emission with a large Stokes shift and substantial exciton-phonon coupling. In both open (self-cavity) and closed cavities, thickness-dependent and angle-resolved reflectance spectra exhibit clear anticrossing, yielding large Rabi splittings of approximately 500 meV. These values are among the largest reported in the UV, positioning thiorene as a promising platform for UV polariton lasers and polariton-enabled photochemistry.

Cryogenic computing platforms for quantum information processing, superconducting logic and space electronics demand non-volatile memories that can simultaneously deliver nanosecond programming, low-voltage operation, multi-level storage and long-term retention below 20 K. Conventional Flash memories, which rely on Fowler–Nordheim (FN) tunnelling or hot-carrier injection through oxide barriers, require large electric fields and exhibit pronounced temperature dependence, limiting both speed and energy efficiency at cryogenic temperatures. Ferroelectric memories offer low-voltage polarization switching and can operate at reduced temperatures; however, achieving stable, finely resolved multibit states remains challenging, particularly in scaled devices where switching is governed by stochastic domain evolution. Here we report a cryogenic non-volatile memory that exploit direct quantum tunnelling from a metallic gate into trap states within the layered van der Waals (vdW) insulator AgInP2S6 across its intrinsic vdW air gap. The stored charge is read non-destructively using a MoS2 field-effect transistor channel. Programming is mediated by temperature-insensitive direct tunnelling rather than field-driven FN injection, enabling ultra-fast operation without high-voltage overhead. The device operates at 15 K with programming times of ~ 30 ns at write voltages below 5 V, endurance exceeding 106 cycles and projected retention approaching 100 days. We further resolve more than 128 distinct and stable conductance states, corresponding to 7-bit storage within a single device. By harnessing the atomically thin vdW gap as an intrinsic quantum tunnelling barrier, this architecture establishes a compact and scalable route to high-density cryogenic memory and a pathway to reduced latency and interconnect overhead in quantum–classical interfaces.

Chiral phonons are mirror-symmetric vibrations with nonzero angular momenta that correspond to twisting and rotational motions of multiple atoms. In chiral crystals, these include low-energy terahertz (THz)-range vibrations of the molecular segments involving dozens of atoms with energies sensitive to molecular chirality. Here, we present spectral signatures of chiral phonons in circularly polarized Raman optical activity (ROA) spectra from enantiomers of amino acid crystals. Along with complementary THz circular dichroism (TCD) measurements, our ROA data reveal several vibrational bands in enantiomers of valine, alanine, tyrosine, and proline between 30 and 150 cm-1 (∼1-4.5 THz) that exhibit opposite intensities. Density functional theory calculations confirm their assignment to twisting and shearing molecular motions. The simultaneous registration of chiral phonon modes by ROA and TCD demonstrates the necessity of these complementary techniques to identify complex mirror-asymmetric vibrational modes and offers new insights into their interactions with circularly polarized light.

Two-dimensional (2D) materials are promising platforms for phonon polaritons (PhPs)—hybrid modes arising from photon-phonon interactions—that enable subwavelength light confinement and optoelectronic functionalities. γ-indium selenide (γ-InSe), an emerging 2D semiconductor with thickness-dependent optoelectronic properties, offers a unique system to explore confined surface phonon polaritons (SPhPs). Here, we employ tilt angle-dependent resonant Raman spectroscopy to measure SPhPs in γ-InSe flakes with thicknesses from 10 nm to 1.2 μm, exfoliated on SiO2 and sapphire substrates. We observe a pronounced thickness-dependent dispersion of the polar A1(TO) phonon mode, with a maximal slope near 100-nm thickness, corresponding to the inverse absorption coefficient. Moreover, differences in the polariton dispersion on SiO2 and sapphire show a dependence on the dielectric environment. The dispersions align with calculations modeling the flakes as Fabry-Perot cavities supporting confined SPhPs. These findings advance our understanding of light-matter interactions in γ-InSe and highlight the potential for their use in nanophotonic devices.

The anomalous Hall effect (AHE) in magnetic systems is typically governed by symmetry constraints that require the Hall response to be proportional to the out-of-plane magnetization component. Here we demonstrate the emergence of an unconventional in-plane AHE in a low-dimensional heterostructure. By interfacing a low-symmetry topological semimetal with a ferromagnetic insulator, we realize a system with reduced symmetry in which only a single mirror plane is preserved. When the magnetization acquires a finite component within this mirror plane, the remaining symmetry is broken, enabling a Hall response that depends on both in-plane and out-of-plane magnetization components. Measurements across multiple devices reveal a gate-tunable AHE, indicating electrostatic control of the underlying mechanisms. A minimal symmetry-constrained microscopic model shows that interfacial spin-orbit coupling and exchange interaction are responsible for the observed multidirectional AHE response. Our work establishes a pathway for engineering tunable, symmetry-driven Hall effects in low-dimensional quantum materials.

Two-dimensional (2D) materials, due to their remarkable physical and chemical properties, hold significant potential for future optical and electrical applications. In this study, the synthesis of 2D phlogopite (magnesium-rich mica) via liquid-phase exfoliation (LPE) is reported using an efficient and scalable procedure. XRD structural analysis revealed a preferential orientation along the (033) plane, whereas AFM and SEM demonstrated a nanoscale thickness and homogeneous morphology. Optical characterisation by UV-Vis and Raman spectroscopy shows tuneable band gaps up to 4.52 eV for the exfoliated 2D phlogopite and distinct vibrational modes indicative of structural evolution. At intense laser conditions, three-photon saturable absorption (3PSA) behaviour was evidenced by light-modulated electrical property studies, which emphasise the potential for optical limiting, switching, and mode-locking applications. The present investigation indicates 2D phlogopite as a versatile material for next-generation optoelectronic devices of high-intensity light modulation.

CuInP2S6 (CIPS) is a two-dimensional van der Waals material that is ferrielectric at room temperature (TC of 315 K). This TC can be raised up to 335 K by synthesizing CIPS with Cu deficiencies (Cu1-xIn1+x/3P2S6, CIPS-IPS), which causes the material to self-segregate into separate CIPS and In4/3P2S6 (IPS) domains. Using Brillouin light scattering microscopy, we examine the phonon spectra of CIPS, IPS, and CIPS-IPS (x = 0.2, 0.3, 0.5, 0.6, 0.8) at room temperature and across TC. We observe unique longitudinal acoustic (LA) phonon signatures for pure CIPS and IPS; however, the CIPS-IPS samples host LA phonons corresponding to both CIPS and IPS, due to the formation of the in-plane heterostructures. These phonons soften in CIPS and CIPS-IPS near their respective values of TC, and there are sharp discontinuities in the phonon frequencies at TC, indicative of the ferrielectric-to-paraelectric phase transition. The temperature and width of this transition is dependent on composition, with pure CIPS showing the sharpest transition at 40.0 °C, while reduction in Cu leads to broadening and an increased TC, caused by the strain exerted on the CIPS domains by the IPS domains. This strain also manifests in IPS domains, as the phonons soften to accommodate the structural change in the CIPS domains.

Photoluminescence (PL) emission in two-dimensional (2D) materials is of great interest for nanophotonics applications. While excitonic emission has been observed in numerous 2D materials, tunable multi-band luminescence is rare. Here, we present single-crystalline AgErP2Se6, a 2D material that exhibits bright, multi-band PL emission from Er3+ ions within the lattice. The emission bands cover a wide range (350- 1,550 nm), with ultra-narrow (as low as 0.5 nm at room temperature) emission peaks and room temperature lifetimes up to 4 ms. The intensities of the PL emission bands from the single crystals depend strongly on temperature and pressure, enabling sensing over a wide temperature and pressure range. Furthermore, the PL persists in exfoliated flakes down to at least 11 nm thick and demonstrates thickness-dependent Purcell enhancement. This work establishes 2D AgErP2Se6 as a multi-band luminescent emitter and sensor, poised to enable integration into a number of optoelectronic and nanophotonic applications.

Structural anisotropy in layered two-dimensional materials can lead to highly anisotropic optical absorption which, in turn, can profoundly affect their phonon modes. These effects include lattice orientation-dependent and excitation energy-dependent mode intensities that can enable next-generation phononic and optoelectronic applications. Here, we report anomalous Raman spectra in single-crystalline AgCrP2Se6, a layered antiferromagnetic material. Density functional theory calculations and experimental measurements reveal several features in the Raman spectra of bulk and exfoliated AgCrP2Se6 crystals including three chiral phonon modes. These modes exhibit large Raman optical activities (circular intensity differences) in bulk AgCrP2Se6, which progressively decrease with thickness. We also observe strong excitation-energy-dependent peak intensities as well as a decrease in anti-Stokes peak intensities at room temperature with increasing excitation energy, resulting in an apparent cooling by up to 220 K. All of these anomalies in bulk and exfoliated flakes are attributed to 1) the ABC layer stacking structure of AgCrP2Se6 and 2) the more constrained metal ion environment in the Se-bounded octahedral cage, causing hybridization between the Se and Ag/Cr electron densities and resulting in charge transfer that strongly affects the electron-phonon coupling. Consequently, this work positions AgCrP2Se6 as an exciting two-dimensional material for optical and phononic applications.

Complex chalcogenides in the MPS_3 family of materials (M = Mn, Fe, Co, and Ni) display remarkably different phase progressions depending upon the metal center orbital filling, character of the P-P linkage, and size of the van der Waals gap. There is also a stacking pattern and spin state difference between the lighter and heavier transition metal-containing systems that places CoPS_3 at the nexus of these activities. Despite these unique properties, this compound is under-explored. Here, we bring together Raman scattering spectroscopy and infrared absorption spectroscopy with X-ray techniques to identify a structural component to the 119 K magnetic ordering transition as well as a remarkable lower temperature set of magnon-phonon pairs that engage in avoided crossings along with a magnetic scattering continuum that correlates with phonon lifetime effects. These findings point to strong spin-phonon entanglement as well as opportunities to control these effects under external stimuli.

The role of Ru promotion of Fe catalysts in the growth of small-diameter single-wall carbon nanotubes (SWCNTs) has been investigated using an Autonomous Research System (ARES)a high throughput, laser-induced chemical vapor deposition (CVD) system capable of in situ Raman spectroscopy. Growth experiments in the ARES were conducted using a standard feedstock (ethylene) at 800 °C for Fe-Ru and Fe catalysts. The results show that Fe-Ru (with a composition ∼10%) supports the growth of small-diameter SWCNTs (less than 1.1 nm) compared to pure Fe. In addition, density functional theory (DFT) calculations on Fe nanoparticle clusters of 55 and 59 atoms with and without adding Ru were performed to probe the effect of Ru on the catalyst stability. The DFT results show that, irrespective of the exact distribution of Ru atoms within these clusters, the addition of Ru to Fe clusters increases the cohesive energy of the catalyst particle with respect to the pure Fe cluster. The combined Raman and DFT data indicate that high-melting-point transition metals can stabilize the catalyst nanoparticles and suppress sintering, thus increasing small-diameter selectivity of SWCNTs. This finding has been verified in a conventional hot-wall CVD system that utilizes industrial gaseous waste as a feedstock using multiexcitation Raman spectroscopy.

The ability to tune fluorescence in polymer composites via 2D materials, dyes, or interfacial modifications provides a versatile platform for advancing optoelectronics as the underlying mechanisms offer control over emission properties, leading to innovative materials. In this work, 2D-white pearl (2D-WP) has been synthesized from naturally occurring WP. Liquid crystal polymer (LCP) composites based on liquid crystal (LC) monomer mixture E7 have been produced via 3D printing. 2D-WP has been dispersed in the LCP composite to demonstrate LC-2D interaction and generation of fluorescence. It has been shown that by introducing interfaces, a secondary emission can be obtained from 2D-dispersed LCP composites. The interactions between the four monomers in E7 and 2D-WP have been simulated, depicting a reduction in the original bandgap of 4.31 eV for 2D-WP to 2.5 eV for LCP-2D composite. In this way, 3D-printed LCP in combination with 2D-WP is shown to be an exciting prospect in further optical and photonics studies.

Aluminum nanoparticles (Al NPs) were synthesized via catalyzed thermal reduction of an aluminum precursor in the presence of a capping ligand. A systematic study was conducted to examine the effect of dilution on nanoparticle synthesis by varying the volume of anhydrous toluene across four dilution factors while maintaining constant molar quantities of the aluminum precursor, catalyst, and ligand. This methodology is relevant for scale-up processes, where more dilute conditions can mitigate nanoparticle reactivity and enhance safety. The resulting Al NPs were characterized with respect to the yield, size distribution, chemical composition (bulk and surface), and morphology. Consistent and favorable yields were observed across all of the dilution conditions. The synthesized Al NPs were further evaluated as low-cost substrates for surface-enhanced Raman spectroscopy (SERS). While Au and Ag nanoparticles are known to exhibit SERS activity in the visible region for chemical warfare agent (CWA) surrogates, little is known about SERS performance in the ultraviolet (UV) region by using metallic substrates. Al NPs, with broadband optical absorption extending from the UV to the near-infrared (NIR), were investigated for this application. Rhodamine 6G (R6G), a standard dye, and dimethyl methylphosphonate (DMMP), a commonly used CWA surrogate, were analyzed by using 248.6 nm UV excitation. The Al NPs exhibited modest SERS activity for both analytes under these conditions. To the best of our knowledge, this is the first report to examine both the synthesis of Al NPs under varying reagent concentrations by changing the solvent volumes and their SERS performance in the UV region for CWA surrogates. Further efforts aimed at reducing particle agglomeration and tailoring surface chemistry are expected to improve sensitivity and enable the development of cost-effective SERS-based sensors for trace CWA detection.