Controlled interlayer exciton ionization in an electrostatic trap in atomically thin heterostructures.

Atomically thin semiconductor heterostructures provide a two-dimensional (2D) device platform for creating high densities of cold, controllable excitons. Interlayer excitons (IEs), bound electrons and holes localized to separate 2D quantum well layers, have permanent out-of-plane dipole moments and long lifetimes, allowing their spatial distribution to be tuned on demand. Here, we employ electrostatic gates to trap IEs and control their density.

Managing Multiple Chronic Conditions during COVID-19 Among Patients with Social Health Risks.

Background: Optimal care for persons with multiple chronic conditions (MCC) requires primary and specialty care continuity, access to multiple providers, social risk assessment, and self-management support. The COVID-19 pandemic abruptly changed primary care delivery to increase reliance on telehealth and virtual care. We report on the experiences of individuals with MCC and their family caregivers on managing their health and receiving health care during the initial pandemic.

Transport Study of Charge-Carrier Scattering in Monolayer WSe_{2}.

Employing flux-grown single crystal WSe_{2}, we report charge-carrier scattering behaviors measured in h-BN encapsulated monolayer field effect transistors. We observe a nonmonotonic change of transport mobility as a function of hole density in the degenerately doped sample, which can be explained by energy dependent scattering amplitude of strong defects calculated using the T-matrix approximation. Utilizing long mean-free path (>500  nm), we also demonstrate the high quality of our electronic devices by showing quantized conductance steps from an electrostatically defined quantum point contact, showing the potential for creating ultrahigh quality quantum optoelectronic devices based on atomically thin semiconductors.

Autosomal dominant GDAP1 mutation with severe phenotype and respiratory involvement: A case report.

Charcot Marie Tooth (CMT) is a heterogeneous group of genetic disorders characterized by progressive motor and sensory neuropathy. CMT is a multi-gene disorder with several possible mutations responsible for a wide range of clinical presentations. A specific mutation of the ganglioside-induced-differentiation-associated protein 1 () gene is associated with the axonal subtype of CMT (CMT2K) which is inherited in an autosomal dominant fashion, as well as the demyelinating subtype (CMT4A) which is inherited in an autosomal recessive pattern.

A Josephson junction with-BN tunnel barrier: observation of low critical current noise.

Decoherence in quantum bits (qubits) is a major challenge for realizing scalable quantum computing. One of the primary causes of decoherence in qubits and quantum circuits based on superconducting Josephson junctions is the critical current fluctuation. Many efforts have been devoted to suppressing the critical current fluctuation in Josephson junctions.

Patients' Reactions to Being Offered Financial Incentives to Increase Colorectal Screening: A Qualitative Analysis.

Purpose: To explore financial incentives as an intervention to improve colorectal cancer screening (CRCS) adherence among traditionally disadvantaged patients who have never been screened or are overdue for screening.

Approach: We used qualitative methods to describe patients' attitudes toward the offer of incentives, plans for future screening, and additional barriers and facilitators to CRCS.

Setting: Kaiser Permanente Washington (KPWA).

Excitons in a reconstructed moiré potential in twisted WSe/WSe homobilayers.

Moiré superlattices in twisted van der Waals materials have recently emerged as a promising platform for engineering electronic and optical properties. A major obstacle to fully understanding these systems and harnessing their potential is the limited ability to correlate direct imaging of the moiré structure with optical and electronic properties. Here we develop a secondary electron microscope technique to directly image stacking domains in fully functional van der Waals heterostructure devices.

A dose-response study of nanosecond electric energy pulses on facial skin.

Nanosecond pulsed electric fields, also known as Nano-Pulse Stimulation or NPS, can trigger regulated cell death to clear skin lesions that are cellular in nature. Before treating facial lesions, it is important to demonstrate the effects of these pulses on normal facial skin. Here we have applied a range of NPS energies to the epidermis and dermis of normal facial skin scheduled for excision to establish a safe dose range of energies prior to use in clinical applications.

Safety and Efficacy of Nanosecond Pulsed Electric Field Treatment of Seborrheic Keratoses.

Background: Nanosecond pulsed electric field technology (also known as Nano-Pulse Stimulation or NPS) is a nonthermal, drug-free, energy-based technology that has demonstrated effects on cellular structures of the dermis and epidermis in previous clinical studies.

Objective: To evaluate the safety and efficacy of a single NPS treatment for clearing seborrheic keratoses (SKs).

Materials And Methods: This study was a prospective, randomized, open-label, multisite, nonsignificant risk trial in which each subject served as their own control.

Electrical control of interlayer exciton dynamics in atomically thin heterostructures.

A van der Waals heterostructure built from atomically thin semiconducting transition metal dichalcogenides (TMDs) enables the formation of excitons from electrons and holes in distinct layers, producing interlayer excitons with large binding energy and a long lifetime. By employing heterostructures of monolayer TMDs, we realize optical and electrical generation of long-lived neutral and charged interlayer excitons. We demonstrate that neutral interlayer excitons can propagate across the entire sample and that their propagation can be controlled by excitation power and gate electrodes.

Safety and Efficacy of Nanosecond Pulsed Electric Field Treatment of Sebaceous Gland Hyperplasia.

Background: Nanosecond pulsed electric field (nsPEF) technology involves delivery of ultrashort pulses of electrical energy and is a nonthermal, drug-free technology that has demonstrated favorable effects on cellular structures of the dermis and epidermis.

Objective: Determine the tolerability and effectiveness of nsPEF treatment of sebaceous gland hyperplasia (SGH).

Methods: This study was a prospective, randomized, open-label, multisite, nonsignificant risk trial in which each subject served as their own control.

Polariton nanophotonics using phase-change materials.

Polaritons formed by the coupling of light and material excitations enable light-matter interactions at the nanoscale beyond what is currently possible with conventional optics. However, novel techniques are required to control the propagation of polaritons at the nanoscale and to implement the first practical devices. Here we report the experimental realization of polariton refractive and meta-optics in the mid-infrared by exploiting the properties of low-loss phonon polaritons in isotopically pure hexagonal boron nitride interacting with the surrounding dielectric environment comprising the low-loss phase change material GeSbTe.

A dose-response study of a novel method of selective tissue modification of cellular structures in the skin with nanosecond pulsed electric fields.

Background And Objectives: This study describes the effects of nanosecond pulsed electric fields (nsPEF) on the epidermis and dermis of normal skin scheduled for excision in a subsequent abdominoplasty. NsPEF therapy applies nanosecond pulses of electrical energy to induce regulated cell death (RCD) in cellular structures, with negligible thermal effects. Prior pre-clinical studies using nsPEF technology have demonstrated the ability to stimulate a lasting immune response in animal tumor models, including melanoma.

Electrically Tunable Exciton-Plasmon Coupling in a WSe Monolayer Embedded in a Plasmonic Crystal Cavity.

We realize a new electroplasmonic switch based upon electrically tunable exciton-plasmon interactions. The device consists of a hexagonal boron nitride (hBN)-encapsulated tungsten diselenide (WSe) monolayer on top of a single-crystalline silver substrate. The ultrasmooth silver substrate serves a dual role as the medium to support surface plasmon polaritons (SPPs) and the bottom gate electrode to tune the WSe exciton energy and brightness through electrostatic doping.

Selective excitation and imaging of ultraslow phonon polaritons in thin hexagonal boron nitride crystals.

We selectively excite and study two new types of phonon-polariton guided modes that are found in hexagonal boron nitride thin flakes on a gold substrate. Such modes show substantially improved confinement and a group velocity that is hundreds of times slower than the speed of light, thereby providing a new way to create slow light in the mid-infrared range with a simple structure that does not require nano-patterning. One mode is the fundamental mode in the first Restrahlen band of hexagonal boron nitride thin crystals on a gold substrate; the other mode is equivalent to the second mode of the second Restrahlen band of hexagonal boron nitride flakes that are suspended in vacuum.

Ultra-confined mid-infrared resonant phonon polaritons in van der Waals nanostructures.

Hexagonal boron nitride has been proposed as an excellent candidate to achieve subwavelength infrared light manipulation owing to its polar lattice structure, enabling excitation of low-loss phonon polaritons with hyperbolic dispersion. We show that strongly subwavelength hexagonal boron nitride planar nanostructures can exhibit ultra-confined resonances and local field enhancement. We investigate strong light-matter interaction in these nanoscale structures via photo-induced force microscopy, scattering-type scanning near-field optical microscopy, and Fourier transform infrared spectroscopy, with excellent agreement with numerical simulations.

Functional Outcomes 18 Months After Total and Midarm Transplantation: A Case Report.

Background: The function reported after arm transplantation is deemed beneficial relative to the marked disability that upper arm amputation causes.

Objective: We report a 51-year-old man with a Disabilities of the Arm, Shoulder and Hand (DASH) score of 75.83 who underwent bilateral arm transplantation in October 2015.

Large Excitonic Reflectivity of Monolayer MoSe_{2} Encapsulated in Hexagonal Boron Nitride.

We demonstrate that a single layer of MoSe_{2} encapsulated by hexagonal boron nitride can act as an electrically switchable mirror at cryogenic temperatures, reflecting up to 85% of incident light at the excitonic resonance. This high reflectance is a direct consequence of the excellent coherence properties of excitons in this atomically thin semiconductor. We show that the MoSe_{2} monolayer exhibits power-and wavelength-dependent nonlinearities that stem from exciton-based lattice heating in the case of continuous-wave excitation and exciton-exciton interactions when fast, pulsed laser excitation is used.

Electrical control of charged carriers and excitons in atomically thin materials.

Electrical confinement and manipulation of charge carriers in semiconducting nanostructures are essential for realizing functional quantum electronic devices. The unique band structure of atomically thin transition metal dichalcogenides (TMDs) offers a new route towards realizing novel 2D quantum electronic devices, such as valleytronic devices and valley-spin qubits . 2D TMDs also provide a platform for novel quantum optoelectronic devices due to their large exciton binding energy.

Mechanical Detection and Imaging of Hyperbolic Phonon Polaritons in Hexagonal Boron Nitride.

Mid-infrared nanoimaging and spectroscopy of two-dimensional (2D) materials have been limited so far to scattering-type scanning near-field optical microscopy (s-SNOM) experiments, where light from the sample is scattered by a metallic-coated atomic force microscope (AFM) tip interacting with the material at the nanoscale. These experiments have recently allowed imaging of plasmon polaritons in graphene as well as hyperbolic phonon polaritons in hexagonal boron nitride (hBN). Here we show that the high mechanical sensitivity of an AFM cantilever can be exploited for imaging hyperbolic phonon polaritons in hBN.

Low-Temperature Ohmic Contact to Monolayer MoS by van der Waals Bonded Co/h-BN Electrodes.

Monolayer MoS, among many other transition metal dichalcogenides, holds great promise for future applications in nanoelectronics and optoelectronics due to its ultrathin nature, flexibility, sizable band gap, and unique spin-valley coupled physics. However, careful study of these properties at low temperature has been hindered by an inability to achieve low-temperature Ohmic contacts to monolayer MoS, particularly at low carrier densities. In this work, we report a new contact scheme that utilizes cobalt (Co) with a monolayer of hexagonal boron nitride (h-BN) that has the following two functions: modifies the work function of Co and acts as a tunneling barrier.