Atomic, Molecular and Optical Physics Commons^™

Some Remarks On Possible Superconductivity Of Composition Pb9Cup6O25, Pablo Abramian-Barco, A. Kuzanyan, Vahan Nikoghosyan, Serafim Teknowijoyo, Armen Gulian

Mathematics, Physics, and Computer Science Faculty Articles and Research

A material called LK-99, a modified-lead apatite crystal structure with the composition Pb₁₀ – ^_xCu_x(PO₄)₆O (0.9 < x < 1.1) has been reported to be an above-room-temperature superconductor at ambient pressure. It is hard to expect that it will be straightforward for other groups to reproduce the original results. We provide here some remarks which may be helpful for a success.

Light That Appears To Come From A Source That Does Not Exist, Itamar Stern, Yakov Bloch, Einav Grynszpan, Merav Kahn, Yakir Aharonov, Justin Dressel, Eliahu Cohen, John C. Howell

Mathematics, Physics, and Computer Science Faculty Articles and Research

Superoscillatory, band-limited functions oscillate faster than their fastest Fourier component. Superoscillations have been intensively explored recently as they give rise to many out-of-the-spectrum phenomena entailing both fundamental and applied significance. We experimentally demonstrate a form of superoscillations which is manifested by light apparently coming from a source located far away from the actual one. These superoscillations are sensed through sharp transverse shifts in the local wave vector at the minima of a pinhole diffraction pattern. We call this phenomenon “optical ventriloquism.”

Questioning Reality: The Progressive Development Of Modern Physics, Joshua Lancman

STEM for Success Showcase

Humanity has a tendency to divide time. The past is distinct from the present which is entirely separate from the future. In supposedly 20-20 vision history is neatly divided into different sections, distinct eras with sharp lines between them. What is present and in the future is always modern. What is past is something else with another name.

Yet time is not divided so neatly. We know this living through it: years and decades blend into one another in a non-uniform progression. To divide human history into separate eras is a necessary simplification, as it helps to ascribe order onto …

Measurement Of Ascorbic Acid Samples' Optical Rotation Via An Improvised Polarimeter For Purity Assessment, Ryan Felicidario, Ramon M. Delos Santos

Physics Faculty Publications

The polarization of light finds practical application in physics and chemistry through the optical activity phenomenon, where polarimeters play a crucial role. This research builds on the improvised polarimeter designed by Kvittingen and Sjursnes, implemented with relevant modifications, to measure optical rotations of over-the-counter ascorbic acid samples. The study aims to assess the purity of two brands of ascorbic acid through polarimetry, comparing the calculated specific rotation with the literature values and supplementing the characterization with melting point determination. The constructed polarimeter, assembled using Lego bricks, provides an affordable alternative for educational purposes, addressing the challenges observed in the accessibility …

Charged Excitons And Trions In The Semiconductor Quantum Dot: Electronic Structure And Effect Of External Fields, Jayden Leonard

Theses, Dissertations and Capstones

In this thesis, we are studying the electronic structures and optical properties of charged excitons and trions (i.e., the exciton-associated quasi-particles in semiconductor materials) in quantum dots which have a three-dimensional confinement configuration. We also consider the effects of an external electric and magnetic field on the charged excitons. Initially theorized in 1958, charged excitons are a fairly new phenomenon in physics in which an exciton (i.e., an electron coupled with an electron hole) is coupled with either another electron or another hole (giving either a ‘negative exciton’ or ‘positive exciton’ accordingly). In the completely confined configuration like the quantum …

Progress In Physics: Twentieth Year Of Publication, Florentin Smarandache, Andreas Ries, Pierre Millette, Ebenezer Chifu

Branch Mathematics and Statistics Faculty and Staff Publications

The journal Progress in Physics was created in January 2005 on behalf of many influential scientists with whom we were in correspondence. The main reason was that publications in other journals were allowed only if the submitter was affiliated with a scientific institution or research organization. Given this situation, many working scientists finding themselves partially employed or unemployed, such as in between research grants, find themselves unable to publish their research results. Even e-print archives such as Cornell’s arXiv required scientific affiliation and still follow this policy.

Compton Scattering Of Mammographic Soft X-Ray Beams By Alkali And Transition Metal Salt Filters Produce X-Ray Interference Zones That May Have Treatment Potential For Localized Cancer Lesions, Subhendra N. Sarkar, Eric Lobel, Sabina Rakhmatova, Derbie Desir, Somdat Kissoon, Daler Djuraev, Katie Tam

Publications and Research

In breast x-ray imaging scattered radiation adds 50% of harmful radiation dose from anisotropic Compton scattering mechanism. We have been working with double layered inorganic salt materials that can induce Compton scattering to the incident mammographic x ray beams (in 20-30 kVp range) with adequate isotropy (angular control). Typically metal nitrates and alkali halide salt layers are shown here to cause low energy radiation interference zones with high and low photon intensities and local flux heterogeneity in terms of flux covariance. Spatial variation of low energy photon flux creates concentrated and sparse radiation zones that may be used to induce …

Quantum Logic Control And Precision Measurements Of Molecular Ions In A Ring Trap: An Approach For Testing Fundamental Symmetries, Yan Zhou, Joshua O. Island, Matt Grau

Physics Faculty Publications

This paper presents an experimental platform designed to facilitate quantum logic control of polar molecular ions in a segmented ring ion trap, paving the way for precision measurements. This approach focuses on achieving near-unity state preparation and detection, as well as long spin-precession coherence. A distinctive aspect lies in separating state preparation and detection conducted in a static frame from parity-selective spin precession in a rotating frame. Moreover, the method is designed to support spatially and temporally coincident measurements on multiple ions prepared in states with different sensitivity to the new physics of interest. This provides powerful techniques to probe …

Characterization Of Nasa Cold Atom Laboratory Potentials Using Variational Techniques, Samuel O. Oni

College of Graduate Studies: Theses & Dissertations

In a recent atom-interferometry (AI) experiment, conducted aboard the NASA Cold Atom Laboratory (CAL) deployed to the International Space Station (ISS), a Bose-Einstein condensate (BEC) was formed too near to the atom chip wall for the AI experiment to be carried out. To fix this the experimentalists tuned the CAL external magnetic field and atom-chip currents so as to move the BEC away from the atom-chip wall. They then planned to turn the trap off and allow it to expand in place (since there is no gravity on the ISS) in preparation for the AI experiment. Unfortunately, when the trap …

Lithium Tetraborate As A Neutron Scintillation Detector: A Review, Elena Echeverria, John W. Mcclory, Lauren Samson, Katherine Shene, Juan A. Colon Santana, Yaroslav V. Burak, Volodymyr T. Adamiv, Ihor M. Teslyuk, Lu Wang, Wai-Ning Mei, Kyle A. Nelson, Douglas S. Mcgregor, Peter A. Dowben, Carolina C. Ilie, James C. Petrosky, Archit Dhingra

Faculty Publications

The electronic structure and translucent nature of lithium tetraborate (Li₂B₄O₇) render it promising as a scintillator medium for neutron detection applications. The inherently large neutron capture cross-section due to ¹⁰B and ⁶Li isotopes and the ease with which Li₂B₄O₇ can be enriched with these isotopes, combined with the facile inclusion of rare earth dopants (occupying the Li⁺ sites), are expected to improve the luminescent properties, as well as the neutron detection efficiency, of Li₂B₄O₇. The electronic structure of both doped …

Ultrafast Electronic Relaxation Pathways Of The Molecular Photoswitch Quadricyclane, Kurtis D. Borne, Joseph C. Cooper, Michael N. R. Ashfold, Julien Bachmann, Surjendu Bhattacharyya, Rebecca Boll5, Matteo Bonanomi, Michael Bosch, Carlo Callegari, Martin Centurion, Marcello Coreno, Basile F. E. Curchod, Miltcho B. Danailov, Alexander Demidovich, Michele Di Fraia, Benjamin Erk, Davide Faccialà, Raimund Feifel, Ruaridh J. G. Forbes, Christopher S. Hansen, David M. P. Holland, Rebecca A. Ingle, Roland Lindh, Lingyu Ma, Henry G. Mcghee, Sri Bhavya Muvva, Joao Pedro Figueira Nunes, Asami Odate, Shashank Pathak, Oksana Plekan, Kevin C. Prince, Primoz Rebernik, Arnaud Rouzée, Artem Rudenko, Alberto Simoncig, Richard J. Squibb, Anbu Selvam Venkatachalam, Caterina Vozzi, Peter M. Weber, Adam Kirrander, Daniel Rolles

Martin Centurion Publications

The light-induced ultrafast switching between molecular isomers norbornadiene and quadricyclane can reversibly store and release a substantial amount of chemical energy. Prior work observed signatures of ultrafast molecular dynamics in both isomers upon ultraviolet excitation but could not follow the electronic relaxation all the way back to the ground state experimentally. Here we study the electronic relaxation of quadricyclane after exciting in the ultraviolet (201 nanometres) using time-resolved gas-phase extreme ultraviolet photoelectron spectroscopy combined with non-adiabatic molecular dynamics simulations. We identify two competing pathways by which electronically excited quadricyclane molecules relax to the electronic ground state. The fast pathway (<100 femtoseconds) is distinguished by effective coupling to valence electronic states, while the slow pathway involves initial motions across Rydberg states and takes several hundred femtoseconds. Both pathways facilitate interconversion between the two isomers, albeit on different timescales, and we predict that the branching ratio of norbornadiene/ quadricyclane products immediately after returning to the electronic ground state is approximately 3:2.

Electro-Optical Effect Of 4-N-Alkyl-Sulfanyl-4' Isothiocyanate-Biphenyl Liquid Crystal Homologous Series Under Terahertz Frequency: A Theoretical Approach, Yogesh Kumar, Narinder Kumar

Makara Journal of Science

This work presented the electro-optical effect of the homologous series 4-n-alkyl-sulfanyl-4'-isothiocyanate-biphenyl (N1SC13H8-SH_2n+1C_n) under an electric field with terahertz (THz) frequency. The increase in alkyl sulfanyl chain length reduces the birefringence but increases the order parameter in THz frequency. An inverse relationship exists between the birefringence and order parameter. Meanwhile, the increase in alkyl sulfanyl chain length increases the refractive index with an even–odd effect. Birefringence, refractive index, order parameter, and director angle show an even–odd effect in the THz frequency range. The calculation is performed between 1 and 1,200 THz frequency. The isothiocyanate stretching corresponding to …

Advancements In Time Resolved Spectroscopy And Nonlinear Microscopy, Bryan Semon

Theses and Dissertations

Non-linear optical processes such as coherent anti-Stokes Raman scattering and sum frequency generation offer a view into the chemical and biological interactions of molecules that is distinctly different from linear techniques like near infra-red and fluorescence. This insight comes at a cost: non-linear techniques are more sensitive to external perturbations of the system, increasing the noise and decreasing the repeatability of the data. We work here on both aspects of these non-linear techniques, taking advantage of their power to offer new imaging techniques as well as working to quantify and reduce the non-resonant noise inherent to the system. In pursuit …

Radiation Exposure Calibration Of The Al2o3:C With Radium-226 And Cesium-137 Using The Osl Method, Selma Tepeli Aydin

All Theses

Optically stimulated luminescence (OSL) dosimetry was utilized to calibrate Al₂O₃:C powder dosimeters, available commercially as the nanoDot® from Landauer Inc., and compare the dosimeter response to radium-226 (²²⁶Ra) and cesium-137 (¹³⁷Cs). The signal from the OSL was quantified using a microSTARii^® OSL reader also produced by Landauer Inc. Dose-response curves were developed for ²²⁶Ra and ¹³⁷Cs experiments (5 dosimeters each) at thirteen absorbed doses. Individual dosimeter response was tracked by serial number. Linear regression analysis was performed to determine if there were significant differences between the intercepts of the …

The Study Of The Polarization Domains Of Mbe-Grown Barium Titanate Thin Films And Nanodots Using Pfm, Mohammad Zamani-Alavijeh

Graduate Theses and Dissertations

Polarization domains are the fundamental elements in ferroelectric materials that contribute to their properties. A natural polarization domain, which possesses a specific polarization direction or state, typically ranges in size from one unit cell to a few micrometers. Therefore, studying polarization domains requires the fabrication of materials and the measurement of ferroelectric properties at the nanoscale. In this study, molecular beam epitaxy (MBE) is employed to fabricate barium titanate (BTO) crystals, and piezoresponse force microscopy (PFM) is used to measure the properties of polarization domains at the nanoscale. In the beginning, this study identifies the reflection of high-energy electron diffraction …

Analyzing The Effects Of Ultrafast Laser Processing On Mechanical Properties Of 3d-Printed Pla Parts, Darshan Pramodbhai Yadav

Theses and Dissertations

Recent advances in additive manufacturing technologies have already led to wide-scale adoption of 3D-printed parts in various industries. The expansion in choice of materials that can be processed, particularly using Fused Deposition Modeling (FDM), and the steady advancements in dimensional accuracy control have extended the range of applications far beyond rapid prototyping. However, additive manufacturing still has considerable limitations compared to traditional and subtractive manufacturing processes. This work addresses limitations associated with the as-deposited surface roughness of 3D-printed parts. The effects of roughness-induced stress concentrations were studied on ultimate tensile strength and fatigue life. The samples were manufactured using a …

Nuclear Charge Radius Determination Of Iridium Using Euv Spectroscopy Of Highly Charged Ions, Adam Hosier

All Dissertations

Highly charged ions have emerged on the scene of atomic physics because of their compressed electron cloud enhancing various physical phenomena. While transitions in ions and highly charged ions provide valuable information to different communities, their application in nuclear charge radius measurements becomes increasingly prominent. In this work, we report the extreme ultra-violet spectroscopy of Na-like ions and x-ray spectroscopy of Cu-like, Co-like, and Ni-like ions that explore nuclear charge distributions and the identification of new transitions, respectively.

In the first part of this work, extreme ultra-violet spectroscopy of highly charged ions of Na-like osmium and iridium was performed using …

Robust Zero Modes In Non-Hermitian Systems Without Global Symmetries, Jose D. H. Rivero, Courtney Fleming, Bingkun Qi, Liang Feng, Li Ge

Publications and Research

We present an approach to achieve zero modes in lattice models that do not rely on any symmetry or topology of the bulk, which are robust against disorder in the bulk of any type and strength. Such symmetry-free zero modes (SFZMs) are formed by attaching a single site or small cluster with zero mode(s) to the bulk, which serves as the “nucleus” that expands to the entire lattice. We identify the requirements on the couplings between this boundary and the bulk, which reveals that this approach is intrinsically non-Hermitian. We then provide several examples with either an arbitrary or structured …

Acoustically Levitated Whispering-Gallery Mode Microlasers, H. M. Reynoso-De La Cruz, E. D. Hernández-Campos, E. Ortiz-Ricardo, A. Martínez-Borquez, I. Rosas-Román, V. Contreras, G. Ramos-Ortiz, B. Mendoza-Santoyo, Cecilia Zurita-Lopez, R. Castro-Beltrán

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Acoustic levitation has become a crucial technique for contactless manipulation in several fields, particularly in biological applications. However, its application in the photonics field remains largely unexplored. In this study, we implement an affordable and innovative phased-array levitator that enables stable trapping in the air of micrometer dye-doped droplets, thereby enabling the creation of microlasers. For the first time, this paper presents a detailed performance of the levitated microlaser cavity, supported by theoretical analysis concerning the hybrid technology based on the combination of whispering-gallery modes and acoustic fields. The pressure field distribution inside the acoustic cavity is numerically solved and …

Relativistic Ultrafast Electron Diffraction At High Repetition Rates, K. M. Siddiqui, D. B. Durham, F. Cropp, F. Ji, S. Paiagua, C. Ophus, N. C. Andresen, L. Jin, J. Wu, S. Wang, X. Zhang, W. You, M. Murnane, Martin Centurion, X. Wang, D. S. Slaughter, R. A. Kaindl, P. Musumeci, A. M. Minor, D. Filippetto

Martin Centurion Publications

The ability to resolve the dynamics of matter on its native temporal and spatial scales constitutes a key challenge and convergent theme across chemistry, biology, and materials science. The last couple of decades have witnessed ultrafast electron diffraction (UED) emerge as one of the forefront techniques with the sensitivity to resolve atomic motions. Increasingly sophisticated UED instruments are being developed that are aimed at increasing the beam brightness in order to observe structural signatures, but so far they have been limited to low average current beams. Here, we present the technical design and capabilities of the HiRES (High Repetition-rate Electron …