arXiv subjects

Ingrid Torres

Publications and source records attributed to Ingrid Torres.

7 recordsLinked to original sources

arXiv2026

From Flat-Optics Concept to Qualified Hardware: Skills Map for the Meta-Optics and Diffractive Optics Workforce

Flat optics is now judged by more than a strong simulation or a single laboratory demonstration. To reach release, a device must survive a chain of handoffs: requirements, model selection, verification, layout release, fabrication, calibrated validation, packaging, and qualification. Diffractive optics brings mature routes for beam shaping and compact wavefront control, while meta-optics expands the design space through wavelength-scale control of phase, amplitude, and polarization. In both families, projects often slow down not because the optical function is impossible, but because the evidence required at each handoff is incomplete, poorly documented, or mismatched to the next decision. This tutorial organizes that problem into a stage-gate workflow, a set of compact technical checks, worked device examples, an artifact-based skills map, and an educational translation into workforce models, course deliverables, and assessment logic. The emphasis is practical: reduce avoidable redesign loops, make performance claims auditable, and clarify what students, instructors, and employers should be able to produce, review, and approve. The broader aim is to make the path from flat-optics concept to qualified hardware easier to understand, easier to teach, and easier to repeat.

physics.optics↗

arXiv2026

Quantum Magnetometers for Infrastructure Inspection and Monitoring

Damage in infrastructure is often hidden until it becomes costly or dangerous. Common examples include corrosion under insulation, early fatigue damage in steel, corrosion of embedded reinforcement, and abnormal current flow in batteries and power equipment. Magnetic methods are attractive because they can sense through coatings, insulation, and concrete cover without couplants, but field performance is often limited by lift-off, low-frequency drift, background magnetic noise, and the weak low-frequency response of pickup coils. This review examines two room-temperature quantum receiver platforms: optically pumped atomic magnetometers (OPMs) and nitrogen-vacancy (NV) diamond magnetometers. Rather than treating them as stand-alone sensors, we compare them as parts of a full measurement chain that includes source physics, geometry, readout, calibration, and interpretation. The literature is organized into four magnetic signal classes: driven induction responses, leakage fields in magnetic flux leakage inspection, passive self-fields linked to stress or corrosion, and fields produced by operational currents. OPMs are strongest for low-frequency, phase-referenced induction measurements, while NV sensors are strongest for near-surface field mapping, vector or gradient measurements, and differential current sensing in compact solid-state heads. Across all applications, deployment depends less on best-case sensitivity than on usable bandwidth, dynamic range, background rejection, geometry control, calibration, and validation. The clearest path to field use is therefore robust instrument engineering tied to qualification methods that reflect real inspection conditions.

physics.app-ph↗

arXiv2026

Twist-Tuned Bilayer Metasurface for 3T MRI

Magnetic resonance imaging (MRI) can see deep inside the body without ionizing radiation, but image quality depends strongly on how well the radio-frequency field is controlled. Passive resonant pads and metasurfaces can help, yet they often lose their tuning when they are placed next to water-rich tissue or tissue-like materials. Here we show a simple way to bring such a device back into tune. We built a bilayer metasurface made of two aluminum wire arrays. One layer can rotate relative to the other, and the gap between the two layers can also be adjusted. Bench measurements show that adding a controlled water load shifts the resonance to lower frequency by about \SIrange{4.2}{11.4}{\mega\hertz}. Rotating the layers shifts it back by about \SIrange{13.2}{14.9}{\mega\hertz}, which is much stronger than changing the gap alone. One loaded setting lands essentially at the proton frequency used in \SI{3}{\tesla} MRI. In a proof-of-concept scan on a clinical \SI{3}{\tesla} system, the metasurface made internal features in a structured pineapple phantom easier to see than in a substrate-only control. These results show that a passive MRI metasurface can be tuned after fabrication and retuned under load using geometry alone, opening a practical route to simple adjustable RF accessories for MRI.

physics.optics↗

arXiv2025

Twist-Tuned Strong Coupling in Sub-GHz Wire Metasurface Bilayers

Twist-angle control offers a bias-free route to reconfigurable metasurfaces, yet its extension to deeply subwavelength resonant platforms at VHF/UHF remains limited. We demonstrate a sub-GHz double-layer wire metasurface formed by two identical wire grids separated by a gap G, with in-plane rotation angle as the sole tuning parameter. One-port, loop-coupled S11 measurements supported by full-wave simulations reveal twist-driven hybridization of the dominant resonant manifold. For small G, the lower hybrid resonance redshifts continuously from 409 MHz to 210 MHz (2:1 tuning), enabling compact, twist-programmable resonant surfaces. Simulations further show that twisting imprints moire-like magnetic near-field super-modulations. From resonance frequencies, linewidths, and normal-mode splitting extracted from the complex response, we obtain normalized coupling up to g = 0.43 with cooperativity exceeding unity over broad angular ranges, meeting the resolved-splitting criterion. The rapid collapse of tunability at larger G confirms the near-field origin of the interaction.

physics.optics↗

arXiv2025

A Cryogenic Dielectric Antenna for Wireless Sensing and Interfacing Outside the 10 K Environment

The performance and scalability of cryogenic microwave systems, particularly for quantum processors, are fundamentally limited by the thermal stability and loss of their constituent dielectric materials. While mixed titanate ceramics like MgTiO3-CaTiO3 (MCT) and (Zr,Sn)TiO4 (ZST) are primary candidates, their comparative performance as radiative antennas in the deep-cryogenic regime has remained uncharacterized. Here we present a side-by-side comparison of MCT and ZST operated as dielectric resonator antennas from 296 K down to 7-10 K under identical fixtures and protocols. While the MCT resonator exhibits large, nonlinear frequency drift (230 MHz by 10 K), pronounced thermal hysteresis, and a collapse of the loaded quality factor at low temperature-behavior consistent with incipient/relaxor-like losses, the ZST resonator demonstrates exceptional stability. Its resonant frequency shifts by only 30 MHz, its loaded Q-factor is enhanced by 20-25%, and it shows negligible thermal hysteresis. Leveraging these properties, we operate the ZST disk as a radiative antenna at 10 K with only 1 mW input, establishing a through-window wireless link that detects room-temperature dielectric targets over multiple wavelengths via near-field frequency shifts and far-field magnitude modulations. This presents a viable path toward non-invasive cryogenic diagnostics and wireless interconnects that circumvent the thermal load of physical cabling. Our findings establish ZST as a foundational material for high-coherence quantum interfaces and provide a practical template for designing wireless cryogenic systems.

physics.optics↗

arXiv2024

Twist-Controlled Wire Metasurfaces

Twistronics, originally conceptualized within the electronics domain to modulate electronic properties through the twist angle between stacked two-dimensional (2D) materials, presents a groundbreaking approach in material science. This concept's extension to photonics, especially using metasurfaces, offers a promising avenue for manipulating light at subwavelength scales across a broad electromagnetic spectrum. Nevertheless, the possibilities that twistronics presents within the realm of photonics are still significantly untapped. In this work, we explore a photonic configuration consisting of a dual-layer wire metasurface operating within the microwave frequency spectrum, where the interlayer twist angle governs the system. Our findings reveal that such manipulation significantly alters the electromagnetic response of the structure, leading to enhanced resonances, tunability, and mode coupling. This twist-induced modulation results in a resonance shift towards the low-frequency range, effectively miniaturizing the structure's electrical dimension. Our study demonstrates the feasibility of integrating twistronics into photonic designs and opens new pathways for developing tunable and reconfigurable photonic devices.

physics.app-ph↗

arXiv2016

Robust Ferromagnetism in Silicene Nanoflakes through Patterned Hydrogenation

Considerably different properties emerge in nanomaterials as a result of quantum confinement and edge effects. In this study, the electronic and magnetic properties of quasi zero dimensional silicene nanoflakes (SiNFs) are investigated using first principles calculations. Whilst the zigzag edged hexagonal SiNFs exhibit nonmagnetic semiconducting character, the zigzag edged triangular SiNFs are magnetic semiconductors. One effective method of harnessing the properties of silicene is hydrogenation owing to its reversibility and controllability. From bare SiNFs to half hydrogenated and then to fully hydrogenated, a triangular SiNF experiences a change from ferrimagnetic to very strong ferromagnetic, and then to non-magnetic. Nonetheless, a hexagonal SiNF undergoes a transfer from nonmagnetic to very strong ferromagnetic, then to nonmagnetic. The half hydrogenated SiNFs produce a large spin moment that is directly proportional to the square of the flakes size. It has been revealed that the strong induced spin magnetizations align parallel and demonstrates a collective character by large range ferromagnetic exchange coupling, giving rise to its potential use in spintronic circuit devices. Spin switch models are offered as an example of one of the potential applications of SiNFs in tuning the transport properties by controlling the hydrogen coverage.

cond-mat.mes-hall↗