Regimes of stability of accelerator modes

The phase diagram of a simple area-preserving map, which was motivated by the quantum dynamics of cold atoms, is explored analytically and numerically. Periodic orbits of a given winding ratio are found to exist within wedge-shaped regions in the phase diagrams, which are analogous to the Arnol'd tongues which have been extensively studied for a variety of dynamical systems, mostly dissipative ones. A rich variety of bifurcations of various types are observed, as well as period doubling cascades. Stability of periodic orbits is analyzed in detail.Comment: Submitted to Physica

Life Around the Hyphen: Inherited Legacies and Their Impact on How We Teach, Write and Talk about Exile/Immigrant Experiences

The Exile Studies Program In Collaboration with: The Betsy-South Beach Hotel The Department of English The College of Arts, Sciences & Education Panel Discussionhttps://digitalcommons.fiu.edu/cri_events/1327/thumbnail.jp

Photon emission correlation spectroscopy as an analytical tool for quantum defects

Photon emission correlation spectroscopy has a long history in the study of atoms, molecules, and, more recently, solid-state quantum defects. In solid-state systems, its most common use is as an indicator of single-photon emission, a key property for quantum technology. However, photon correlation data can provide a wealth of information about quantum emitters beyond their single-photon purity$\,-\,$information that can reveal details about an emitter's electronic structure and optical dynamics that are hidden by other spectroscopy techniques. We present a standardized framework for using photon emission correlation spectroscopy to study quantum emitters, including discussion of theory, data acquisition, analysis, and interpretation. We highlight nuances and best practices regarding the commonly-used $g^{(2)}(\tau=0)<0.5$ test for single-photon emission. Finally, we illustrate how this experimental technique can be paired with optical dynamics simulations to formulate an electronic model for unknown quantum emitters, enabling the design of quantum control protocols and assessment of their suitability for quantum information science applications.Comment: 20 pages, 7 figures. Updates in version 2 include an expanded section VI and the addition of two figures and an appendi

Efficient Analysis of Photoluminescence Images for the Classification of Single-Photon Emitters

Solid-state single-photon emitters (SPE) are a basis for emerging technologies such as quantum communication and quantum sensing. SPE based on fluorescent point defects are ubiquitous in semiconductors and insulators, and new systems with desirable properties for quantum information science may exist amongst the vast number of unexplored defects. However, the characterization of new SPE typically relies on time-consuming techniques for identifying point source emitters by eye in photoluminescence (PL) images. This manual strategy is a bottleneck for discovering new SPE, motivating a more efficient method for characterizing emitters in PL images. Here we present a quantitative method using image analysis and regression fitting to automatically identify Gaussian emitters in PL images and classify them according to their stability, shape, and intensity relative to the background. We demonstrate efficient emitter classification for SPEs in nanodiamond arrays and hexagonal boron nitride flakes. Adaptive criteria detect SPE in both samples despite variation in emitter intensity, stability, and background features. The detection criteria can be tuned for specific material systems and experimental setups to accommodate the diverse properties of SPE.Comment: 11 pages, 1 table, 4 figure

Probing the Optical Dynamics of Quantum Emitters in Hexagonal Boron Nitride

Hexagonal boron nitride is a van der Waals material that hosts visible-wavelength quantum emitters at room temperature. However, experimental identification of the quantum emitters' electronic structure is lacking, and key details of their charge and spin properties remain unknown. Here, we probe the optical dynamics of quantum emitters in hexagonal boron nitride using photon emission correlation spectroscopy. Several quantum emitters exhibit ideal single-photon emission with noise-limited photon antibunching, $g^{(2)}(0)=0$. The photoluminescence emission lineshapes are consistent with individual vibronic transitions. However, polarization-resolved excitation and emission suggests the role of multiple optical transitions, and photon emission correlation spectroscopy reveals complicated optical dynamics associated with excitation and relaxation through multiple electronic excited states. We compare the experimental results to quantitative optical dynamics simulations, develop electronic structure models that are consistent with the observations, and discuss the results in the context of ab initio theoretical calculations.Comment: 31 pages, 16 figures, 6 table

Dynamical Characterization and Room-Temperature Control of an Optically Addressable Single Spin in Hexagonal Boron Nitride

Hexagonal boron nitride (h-BN), a wide bandgap, two-dimensional solid-state material, hosts pure single-photon emitters that have shown signatures of optically-addressable electronic spins. Here, we report on a single emitter in h-BN exhibiting optically detected magnetic resonance at room temperature, and we propose a model for its electronic structure and optical dynamics. Using photon emission correlation spectroscopy in conjunction with time-domain optical and microwave experiments, we establish key features of the emitter's electronic structure. Specifically, we propose a model that includes a spinless optical ground and excited state, a metastable spin-1/2 configuration, and an emission modulation mechanism. Using optical and spin dynamics simulations, we constrain and quantify transition rates in the model, and we design protocols that optimize the signal-to-noise ratio for spin readout. This constitutes a necessary step toward quantum control of spin states in h-BN.Comment: 14 pages, 15 figures. arXiv admin note: text overlap with arXiv:2201.0888

Nonprescribed Antimicrobial Drugs in Latino Community, South Carolina

We investigated in a sample of Latinos the practices of antimicrobial drug importation and use of nonprescribed antimicrobial drugs. In interviews conducted with 219 adults, we assessed health beliefs and past and present behaviors consistent with acquiring antimicrobial drugs without a prescription in the United States. Many (30.6%) believed that antimicrobial drugs should be available in the United States without a prescription. Furthermore, 16.4% had transported nonprescribed antimicrobial drugs into the United States, and 19.2% had acquired antimicrobial agents in the United States without a prescription. A stepwise logistic regression analysis showed that the best predictors of having acquired nonprescribed antimicrobial drugs in the United States were beliefs and behavior consistent with limited regulations on such drugs. Many persons within the Latino community self-medicate with antimicrobial drugs obtained without a prescription both inside and outside the United States, which adds to the reservoir of antimicrobial drugs in the United States

Assessing Health Care Use and Cost Consequences of a New Screening Modality: The Case of Digital Mammography

Full-field digital mammography (FFDM) has largely replaced screen-film mammography (SFM) for breast cancer screening, but how this affects downstream breast-related use and costs is unknown