arXiv subjects

Adam Alfieri

Publications and source records attributed to Adam Alfieri.

5 recordsLinked to original sources

arXiv2025

Experimental demonstration of corrugated nanolaminate films as reflective light sails

Achieving laser-driven, reflective, relativistic light sails would represent a tremendous breakthrough for humankind, allowing us to advance our understanding of the solar system and deep space far beyond what we know from space probes, telescopes, and objects passing near Earth. Numerous sail film designs have been proposed, but none have been demonstrated that satisfy all of the stringent optical, mechanical, and mass budget constraints. Here we overcome this challenge by experimentally demonstrating a novel class of optically-optimized nanolaminate sails with strong and flexible hexagonally-corrugated microstructures. Our prototypes, fabricated from alumina and molybdenum disulfide using scalable semiconductor processing techniques, feature ultra-low areal densities of <1 g/m^2 and achieve experimentally-measured reflectivities of >50% and absorptivities of <4% within the Doppler-shifted laser wavelength range corresponding to accelerating to a fifth the speed of light. Moreover, we analyze reflectivity, strength, and mass constraints to show that our sails have the potential to achieve greater maximum velocities than other sail designs in the literature. Broadly, our films mark a significant leap forward toward plausible relativistic interstellar propulsion for intragalactic exploration

physics.optics↗

arXiv2023

Giant Optical Anisotropy in 2D Metal-Organic Chalcogenates

Optical anisotropy is a fundamental attribute of some crystalline materials and is quantified via birefringence. A birefringent crystal not only gives rise to asymmetrical light propagation but also attenuation along two distinct polarizations, a phenomenon called linear dichroism (LD). Two-dimensional (2D) layered materials with high in- and out-of-plane anisotropy have garnered interest in this regard. Mithrene, a 2D metal-organic chalcogenate (MOCHA) compound, exhibits strong excitonic resonances due to its naturally occurring multi-quantum well (MQW) structure and in-plane anisotropic response in the blue wavelength (~400-500 nm) regime. The MQW structure and the large refractive indices of mithrene allow the hybridization of the excitons with photons to form self-hybridized exciton-polaritons in mithrene crystals with appropriate thicknesses. Here, we report the giant birefringence (~1.01) and tunable in-plane anisotropic response of mithrene, which stem from its low symmetry crystal structure and unique excitonic properties. We show that the LD in mithrene can be tuned by leveraging the anisotropic exciton-polariton formation via the cavity coupling effect exhibiting giant in-plane LD (~77.1%) at room temperature. Our results indicate that mithrene is an ideal polaritonic birefringent material for polarization-sensitive nanophotonic applications in the short wavelength regime.

physics.optics↗

arXiv2023

Gate-Tunable Optical Anisotropy in Wafer-Scale, Aligned Carbon-Nanotube Films

Telecommunications and polarimetry both require the active control of the polarization of light, Currently, this is done by combining intrinsically anisotropic materials with tunable isotropic materials into heterostructures using complicated fabrication techniques due to the lack of scalable materials that possess both properties. Tunable birefringent and dichromic materials are scarce and rarely available in high-quality thin films over wafer scales. In this paper, we report semiconducting, highly aligned, single-walled carbon nanotubes (SWCNTs) over 4" wafers with normalized birefringence and dichroism values 0.09 and 0.58, respectively. The real and imaginary parts of the refractive index of the SWCNT films are tuned by up to 5.9% and 14.3% in the infrared at 2200 nm and 1660 nm, respectively, using electrostatic doping. Our results suggest that aligned SWCNTs are among the most anisotropic and tunable optical materials known and opens new avenues for their application in integrated photonics and telecommunications.

physics.optics↗

arXiv2022

Nanomaterials for Quantum Information Science and Engineering

Quantum information science and engineering (QISE) which entails use of quantum mechanical states for information processing, communications, and sensing and the area of nanoscience and nanotechnology have dominated condensed matter physics and materials science research in the 21st century. Solid state devices for QISE have, to this point, predominantly been designed with bulk materials as their constituents. In this review, we consider how nanomaterials (i.e. materials with intrinsic quantum confinement) may offer inherent advantages over conventional materials for QISE. We identify the materials challenges for specific types of qubits, and we identify how emerging nanomaterials may overcome these challenges. Challenges for and progress towards nanomaterials based quantum devices are identified. We aim to help close the gap between the nanotechnology and quantum information communities and inspire research that will lead to next generation quantum devices for scalable and practical quantum applications.

quant-ph↗

arXiv2021

Scalable synthesis of 2D van der Waals superlattices

Heterostructure materials form the basis of much of modern electronics, from transistors to lasers and light-emitting diodes. Recent years have seen a renewed focus on creating heterostructures through the vertical integration of two-dimensional materials, including graphene, hexagonal boron nitride, and transition metal dichalcogenides (TMDCs). However, fundamental challenges associated with materials processing have limited material quality and impeded scalability. We demonstrate a method to convert sub-nanometer metal films deposited on silicon and sapphire into TMDC heterostructures through vapor-phase processing. The resulting heterostructures and superlattices exhibit novel properties compared with stand-alone TMDCs, including reduced bandgap, enhanced light-matter coupling, and improved catalytic performance. This robust and scalable synthetic method provides new opportunities to generate a wide range of artificially stacked 2D superlattices with controlled morphology and composition.

cond-mat.mtrl-sci↗