Gated InAs quantum dots embedded in surface acoustic wave cavities for low-noise optomechanics.

Self-assembled InAs quantum dots (QDs) are promising optomechanical elements due to their excellent photonic properties and sensitivity to local strain fields. Microwave-frequency modulation of photons scattered from these efficient quantum emitters has been recently demonstrated using surface acoustic wave (SAW) cavities. However, for optimal performance, a gate structure is required to deterministically control the charge state and reduce the charge noise of the QDs.

Monolithic Polarizing Circular Dielectric Gratings on Bulk Substrates for Improved Photon Collection from InAs Quantum Dots.

III-V semiconductor quantum dots (QDs) are near-ideal and versatile single-photon sources. Because of the capacity for monolithic integration with photonic structures as well as optoelectronic and optomechanical systems, they are proving useful in an increasingly broad application space. Here, we develop monolithic circular dielectric gratings on bulk substrates - as opposed to suspended or wafer-bonded substrates - for greatly improved photon collection from InAs quantum dots.

Evolving Disparities in Cannabis Use Among Youth by Demographics and Tobacco and Alcohol Use in the U.S.: 2013-2021.

Introduction: This study investigated the prevalence of past 30-day cannabis use among U.S. youth by cigarette use, alcohol use, demographics, and state-of-residence cannabis legal status in 2021 and examined whether changes in cannabis use prevalence were modified by these factors from 2013 to 2021.

Asthma prevalence among US 9th-12th graders who report past 30-day cannabis use in 2019.

Introduction: Little is known about the relationship between cannabis use and asthma among youth in the US. The aims of this study were to estimate prevalence of asthma among youth who reported any cannabis use in the past 30 days, relative to those who did not, and to investigate the relationship between frequency of cannabis use and prevalence of asthma, adjusting for demographic characteristics and cigarette use.

Methods: Data were drawn from the 2019 Youth Risk Behavior Surveillance System (YRBSS), a CDC national high school survey, which collects data from students in grades 9-12 across the US bi-annually.

Cannabis use and the prevalence of current asthma among adolescents and adults in the United States.

Objectives: Cannabis use has increased among adolescents and adults in the United States (US) in recent years. Few data are available on the prevalence of asthma by frequency of cannabis use. This study aimed to estimate the prevalence of asthma by frequency of past 30-day cannabis use among US individuals.

Assessing the Association of Solitary Confinement Ban With Adolescent Self-Harm in New York City Jails.

This study sought to evaluate the association of a solitary confinement ban with self-harm among adolescents in New York City's jail system. Data were extracted from medical records on 5,038 adolescent incarcerations from October 1, 2013, through July 12, 2016, and compared incarcerations before the ban (February 20, 2015) with those after the ban. Of the 2,503 adolescent incarcerations pre-ban, there were 171 self-harm gestures among 106 incarcerations (4.

Central Obesity Is Associated With an Increased Rate of Multisite Pain in Older Adults.

Objective: Central obesity has been associated with several adverse health events, but little research exists about the longitudinal effects of central obesity on multisite pain. The purpose of this study was to assess if central obesity, as measured by waist circumference measurement, was associated with an increased rate of having multisite pain among older adults aged 65 years and older.

Design: The National Health and Aging Trends Study is a longitudinal cohort study initiated in 2011 and intended to be representative of Medicare beneficiaries in the contiguous United States.

The Association of Pain Levels and Low Physical Activity among Older Women.

There is an integral research gap regarding whether there is a relationship between pain levels and low physical activity among older women. This is a secondary analysis of a longitudinal cohort study, the Women's Health and Aging Study (WHAS) II. Our analyses included 436 community-dwelling women between the ages of 70 and 79, who were followed for 10.

Poor Lower Extremity Functioning Is Associated with Modest Increased Incidence of Probable Dementia.

Lower extremity functioning in older adults provides a measure of poor physical performance and can predict negative health outcomes. The consequences of reduced lower extremity functioning on cognitive decline, measured as time-varying variables, have not been well documented in previous studies. We aimed to evaluate whether lower extremity functioning is associated with an increased incidence rate of probable dementia among older adults using data from the National Health and Aging Trends Study (NHATS).

Phonon Dephasing Dynamics in MoS.

A variety of quantum degrees of freedom, e.g., spins, valleys, and localized emitters, in atomically thin van der Waals materials have been proposed for quantum information applications, and they inevitably couple to phonons.

Excitation Ladder of Cavity Polaritons.

Multidimensional coherent spectroscopy directly unravels multiply excited states that overlap in a linear spectrum. We report multidimensional coherent optical photocurrent spectroscopy in a semiconductor polariton diode and explore the excitation ladder of cavity polaritons. We measure doubly and triply avoided crossings for pairs and triplets of exciton polaritons, demonstrating the strong coupling between light and dressed doublet and triplet semiconductor excitations.

Optimization of photoluminescence from W centers in a silicon-on-insulator.

W centers are trigonal defects generated by self-ion implantation in silicon that exhibit photoluminescence at 1.218 µm. We have shown previously that they can be used in waveguide-integrated all-silicon light-emitting diodes (LEDs).

Clinical Outcomes of Specialized Treatment Units for Patients With Serious Mental Illness in the New York City Jail System.

Objective: New York City's (NYC) Correctional Health Services has introduced specialized treatment units for patients with serious mental illness in the NYC jail system. With multidisciplinary mental health staffing and a coordinated approach with NYC's Department of Correction, these units expand therapeutic options for patients vulnerable to clinical instability and physical harm, including those at high risk of psychiatric medication nonadherence and those returning to jail from psychiatric hospitalization. This study evaluated the extent to which these units improve clinical outcomes for this population.

Evidence for moiré excitons in van der Waals heterostructures.

Recent advances in the isolation and stacking of monolayers of van der Waals materials have provided approaches for the preparation of quantum materials in the ultimate two-dimensional limit. In van der Waals heterostructures formed by stacking two monolayer semiconductors, lattice mismatch or rotational misalignment introduces an in-plane moiré superlattice. It is widely recognized that the moiré superlattice can modulate the electronic band structure of the material and lead to transport properties such as unconventional superconductivity and insulating behaviour driven by correlations; however, the influence of the moiré superlattice on optical properties has not been investigated experimentally.

Single-scan acquisition of multiple multidimensional spectra.

Multidimensional coherent spectroscopy is a powerful tool for understanding the ultrafast dynamics of complex quantum systems. To fully characterize the nonlinear optical response of a system, multiple pulse sequences must be recorded and quantitatively compared. We present a new single-scan method that enables rapid and parallel acquisition of all unique pulse sequences corresponding to first- and third-order degenerate wave-mixing processes.

Microsecond Valley Lifetime of Defect-Bound Excitons in Monolayer WSe_{2}.

In atomically thin two-dimensional semiconductors such as transition metal dichalcogenides (TMDs), controlling the density and type of defects promises to be an effective approach for engineering light-matter interactions. We demonstrate that electron-beam irradiation is a simple tool for selectively introducing defect-bound exciton states associated with chalcogen vacancies in TMDs. Our first-principles calculations and time-resolved spectroscopy measurements of monolayer WSe_{2} reveal that these defect-bound excitons exhibit exceptional optical properties including a recombination lifetime approaching 200 ns and a valley lifetime longer than 1  μs.

Quadrature Demodulation of a Quantum Dot Optical Response to Faint Light Fields.

The amplitude and phase of a material's nonlinear optical response provide insight into the underlying electronic dynamics that determine its optical properties. Phase-sensitive nonlinear spectroscopy techniques are widely implemented to explore these dynamics through demodulation of the complex optical signal field into its quadrature components; however, complete reconstruction of the optical response requires measuring both the amplitude and phase of each quadrature, which is often lost in standard detection methods. Here, we implement a heterodyne-detection scheme to fully reconstruct the amplitude and phase response of spectral hole-burning from InAs/GaAs charged quantum dots.

Ultrafast Time-Resolved X-ray Absorption Spectroscopy of Ferrioxalate Photolysis with a Laser Plasma X-ray Source and Microcalorimeter Array.

The detailed pathways of photoactivity on ultrafast time scales are a topic of contemporary interest. Using a tabletop apparatus based on a laser plasma X-ray source and an array of cryogenic microcalorimeter X-ray detectors, we measured a transient X-ray absorption spectrum during the ferrioxalate photoreduction reaction. With these high-efficiency detectors, we observe the Fe K edge move to lower energies and the amplitude of the extended X-ray absorption fine structure reduce, consistent with a photoreduction mechanism in which electron transfer precedes disassociation.

All-silicon light-emitting diodes waveguide-integrated with superconducting single-photon detectors.

We demonstrate cryogenic, electrically injected, waveguide-coupled Si light-emitting diodes (LEDs) operating at 1.22 m. The active region of the LED consists of W centers implanted in the intrinsic region of a -- diode.

Multidimensional coherent photocurrent spectroscopy of a semiconductor nanostructure.

Multidimensional Coherent Optical Photocurrent Spectroscopy (MD-COPS) is implemented using unstabilized interferometers. Photocurrent from a semiconductor sample is generated using a sequence of four excitation pulses in a collinear geometry. Each pulse is frequency shifted by a unique radio frequency through acousto-optical modulation; the Four-Wave Mixing (FWM) signal is then selected in the frequency domain.

Dark pulse quantum dot diode laser.

We describe an operating regime for passively mode-locked quantum dot diode laser where the output consists of a train of dark pulses, i.e., intensity dips on a continuous background.