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Detailed characterization of deep-level color centers requires understanding their electronic and atomic structure, which is most commonly investigated utilizing the Kohn–Sham density functional theory. Standard semilocal functionals based on the generalized gradient approximation (GGA) are inclined toward an imprecise quantitative description of defects' electronic structure. Hybrid functionals provide an improved prediction of electronic properties, albeit at a much higher computational cost. In this work, we test the newly developed Strongly Constrained and Appropriately Normed (SCAN) family of meta-GGA density functionals for selected color centers in diamond. In particular, we study nitrogen-, silicon-, germanium-, and tin-vacancy centers that have been recently investigated for their use in quantum technological applications. We show that SCAN and its derivatives, the rSCAN and r2SCAN functionals, significantly improve the calculated energies of optical transitions within the delta-self-consistent-field approach, almost reaching the accuracy of the hybrid Heyd–Scuseria–Ernzerhof (HSE) functional. In the case of the NV− center, we also show that the SCAN family of functionals improves the description of the adiabatic potential energy surfaces compared to both GGA and hybrid functionals, improving calculated luminescence lineshapes. As a result of these findings, we recommend using the SCAN family of functionals as a promising alternative for studying color centers in solids. [ABSTRACT FROM AUTHOR]

While most of the studies on assistance in talk-in-interaction from the conversation analytic perspective presuppose that the actor who receives assistance already has or is expected to have problems, issues, needs, or demands, assistance can be offered without the expression or existence of plausible expectations of problems, issues, needs, or demands. Using the methodology of conversation analysis, this study explores how service providers frame their offer-related actions as assistance without the customer's expression of concrete needs or demands or their expected emergence by analyzing the sequences in which salespersons offered customers to try the jewelry. The results of the analysis show that salespersons were motivated to execute pull-based offer-related actions in which assistance is provided in response to the expression or anticipation of customer needs, as they could lead to successful sales outcomes. Salespersons employed various techniques to frame their offer-related actions as assistance. [ABSTRACT FROM AUTHOR]

The article "The Omnipresent Gaze: Exploring Surveillance in Amir Naderi's Goodbye Friend (1971)" delves into the concept of surveillance in modern societies, particularly under authoritarian regimes like the Pahlavi state in Iran. The film, a notable example of Iranian New Wave cinema, portrays the pervasive fear of being under constant surveillance through its visual expression and cinematic techniques. It explores the dichotomy between individuals evading detection within the urban crowd and the surveillance entities' relentless efforts to identify them. The film cleverly blurs the lines between narrative storytelling and surveillance, using the camera as both a narrative tool and a surveillance device, reflecting the era's sense of ubiquitous surveillance and societal suffocation. [Extracted from the article]

Copyright of International Journal for Tourism, Archeology & Hospitality (IJTAH) is the property of Beni Suef University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The silicon vacancy (SiV) center in diamond is drawing much attention due to its optical and spin properties, attractive for quantum information processing and sensing. Comparatively little is known, however, about the dynamics governing SiV charge state interconversion mainly due to challenges associated with generating, stabilizing, and characterizing all possible charge states, particularly at room temperature. Here, multi‐color confocal microscopy and density functional theory are used to examine photo‐induced SiV recombination — from neutral, to single‐, to double‐negatively charged — over a broad spectral window in chemical‐vapor‐deposition (CVD) diamond under ambient conditions. For the SiV0 to SiV‐ transition, a linear growth of the photo‐recombination rate with laser power at all observed wavelengths is found, a hallmark of single photon dynamics. Laser excitation of SiV‒, on the other hand, yields only fractional recombination into SiV2‒, a finding that is interpreted in terms of a photo‐activated electron tunneling process from proximal nitrogen atoms. [ABSTRACT FROM AUTHOR]

The nitrogen-vacancy center in diamond attracts a lot of attention in sensing applications, mainly for temperature, magnetic field, and rotation measurements. Nuclear spins of carbon-13 surrounding the nitrogen-vacancy center can be used as a memory or sensing element. In the current work, a diamond plate with a relatively large concentration of carbon-13 was synthesized and examined. The spectrum of optically detected magnetic resonance was recorded and analyzed in a magnetic field range of 5–200 G. A strain-independent measurement technique of carbon-13 isotope concentration based on the analysis of magnetic resonance spectra was developed. Additionally, narrow features in the spectrum were detected and understood. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to use emotions-as-social information theory to investigate how physical (customer perceived store atmosphere) and social servicescapes (customer information searching) influence the effects of employees' positive affective displays on customer outcomes via customer positive moods and positive expectation disconfirmation. Design/methodology/approach: This research included two studies, each using a distinct research design, to empirically test the proposed model. Study 1 involved 200 observational data points on objective purchase amounts from designer watch shops. In Study 2, data were collected from 230 customers in designer jewelry stores. Findings: The results of path analyses revealed that: employee positive affective displays are positively associated with customer purchase outcomes; employee positive affective displays had positive indirect effects on customer purchase outcomes by enhancing customer positive moods and positive expectation disconfirmation; these positive indirect effects were strengthened when customers engaged in information search behaviors; and these positive indirect effects were attenuated when customers perceive store atmosphere as favorable, indicating a substitution effect of customer perceived store atmosphere. Originality/value: Previous research has not thoroughly examined the role of the servicescape in moderating the effects of employees' positive affective displays on customer purchase outcomes. This present study not only clarified the affective and cognitive mechanisms that link employees' positive affective displays on purchase outcomes but also identified servicescape as a critical boundary condition of these effects. [ABSTRACT FROM AUTHOR]

This publication is a digital comic short story based on autoethnographic research. The story takes as its foundation a photo of an African storefront window in the 18th arrondissement of Paris, France in summer 2019. The narrative queries from multiple perspectives and types of information my relationship as an African American woman with several things: the West African jewellery and cloth on display, the window that framed the products for sale, the store, and the neighbourhood that featured a predominately African diasporic population. In this publication, I also address some of the following questions: 1) Can I see myself in this Black, French and African diasporic site of commerce? 2) How does this marketing display relate to American and French marketing and media history's invisibility of Black women as desired consumers? 3) Has my shared ascribed status of race and increased awareness of West African culture after travels to Ghana and Senegal changed my fit in this Francophone African space? [ABSTRACT FROM AUTHOR]

This study introduces a method for reconstructing vector microwave magnetic fields using a single nitrogen-vacancy (NV) center in locally strong effective fields with two different orientations in diamond, without the previously required external magnetic field. Due to the varying orientations of the effective fields, NV centers exhibit two distinct sets of switchable ground states. The resonant Rabi oscillations of an NV center in these two distinct states were utilized to reconstruct vector microwave magnetic fields. Remarkably, this technique achieves an angular resolution of 0.02 mrad / Hz . Overcoming the limitations inherent in previous practices of using NV ensembles, this breakthrough has the potential to substantially enhance both the spatial resolution and the sensitivity of microwave magnetic field imaging, a meaningful development for various scientific and technological applications. [ABSTRACT FROM AUTHOR]

Single-color centers in thin polycrystalline diamond membranes allow the platform to be used in integrated quantum photonics, hybrid quantum systems, and other complex functional materials. While single-crystal diamond membranes are still technologically challenging to fabricate as they cannot be grown on a non-diamond substrate, free-standing polycrystalline diamond membranes can be conveniently fabricated at large-scale from nanocrystalline diamond seeds on a substrate that can be selectively etched. However, their practical application for quantum photonics is so far limited by crystallographic defects, impurities, graphitic grain boundaries, small grain sizes, scattering loss, and strain. In this paper, we report on a single-photon source based on silicon-vacancy color centers in a polycrystalline diamond membrane. We discuss the spectroscopic approach and quantify the photon statistics, obtaining a g2(0) ≈ 0.04. Our findings hold promise for introducing polycrystalline diamond to quantum photonics and hybrid quantum systems. [ABSTRACT FROM AUTHOR]

Group IV vacancy color centers in diamond are promising spin-photon interfaces with strong potential for applications in photonic quantum technologies. Reliable methods for controlling and stabilizing their charge state are urgently needed for scaling to multiqubit devices. Here, we manipulate the charge state of silicon vacancy (SiV) ensembles by combining luminescence and photocurrent spectroscopy. We controllably convert the charge state between the optically active SiV- and dark SiV2- with megahertz rates and >90% contrast by judiciously choosing the local potential applied to in-plane surface electrodes and the laser excitation wavelength. We observe intense SiV- photoluminescence under hole capture, measure the intrinsic conversion time from the dark SiV2- to the bright SiV- to be 36.4(67) ms, and demonstrate how it can be enhanced by a factor of 105 via optical pumping. Moreover, we obtain previously unknown information on the defects that contribute to photoconductivity, indicating the presence of substitutional nitrogen and divacancies. [ABSTRACT FROM AUTHOR]

Quantum magnetometry based on optically detected magnetic resonance (ODMR) of nitrogen vacancy centers in diamond nano or microcrystals is a promising technology for sensitive, integrated magnetic-field sensors. Currently, this technology is still cost-intensive and mainly found in research. Here we propose one of the smallest fully integrated quantum sensors to date based on nitrogen vacancy (NV) centers in diamond microcrystals. It is an extremely cost-effective device that integrates a pump light source, photodiode, microwave antenna, filtering and fluorescence detection. Thus, the sensor offers an all-electric interface without the need to adjust or connect optical components. A sensitivity of 28.32 nT / Hz and a theoretical shot noise limited sensitivity of 2.87 nT / Hz is reached. Since only generally available parts were used, the sensor can be easily produced in a small series. The form factor of (6.9 × 3.9 × 15.9) mm 3 combined with the integration level is the smallest fully integrated NV-based sensor proposed so far. With a power consumption of around 0.1 W , this sensor becomes interesting for a wide range of stationary and handheld systems. This development paves the way for the wide usage of quantum magnetometers in non-laboratory environments and technical applications. [ABSTRACT FROM AUTHOR]

In recent years, the nitrogen-vacancy (NV) center in diamonds has been demonstrated to be a high-performance multiphysics sensor, where a lock-in amplifier (LIA) is often adopted to monitor photoluminescence changes around the resonance. It is rather complex when multiple resonant points are utilized to realize a vector or temperature-magnetic joint sensing. In this article, we present a novel scheme to realize multipoint lock-in detection with only a single-channel device. This method is based on a direct digital synthesizer (DDS) and frequency-shift keying (FSK) technique, which is capable of freely hopping frequencies with a maximum of 1.4 GHz bandwidth and encoding an unlimited number of resonant points during the sensing process. We demonstrate this method in experiments and show it would be generally useful in quantum multi-frequency excitation applications, especially in the portable and highly mobile cases. [ABSTRACT FROM AUTHOR]

The high‐pressure and high‐temperature (HPHT) diamonds with well‐controlled defects and low stress offer an ideal host substrate for the fields of quantum information science; however, fabrication of quantum‐grade HPHT diamonds remains a pressing challenge. Here, a major advance in generating highly coherent nitrogen‐vacancy (NV) centers, a promising spin defect in diamonds, via tailored HPHT synthesis and postgrown annealing treatment is reported. The resulting well‐dispersed single NV− centers in type‐IIa diamonds exhibit long spin coherence times comparable to that of the reported chemical vapor deposition diamonds. Moreover, high‐density NV− ensembles in 〈100〉‐grown type‐Ib diamonds with superb zero‐phonon lines considerably sharper than those of native NV− centers in as‐grown diamonds, together with low splitting of resonances are produced. These findings demonstrate a superior synthesis and optimization protocol for creating high‐quality NV− centers avoiding lattice damage in diamond to meet the stringent requirements for a wide range of emerging quantum technologies. [ABSTRACT FROM AUTHOR]

Quantum diamond sensors of multiple physical quantities, especially magnetic field and temperature, have great application prospects in materials science, biophysics, and engineering. Here, we demonstrate joint quantum sensing of vector magnetic field and temperature based on ensembles of nitrogen-vacancy (NV) centers in the diamond. Combining the intrinsic C 3 ν symmetry of diamond crystals and multiple-frequency excitation technique, we can directly measure frequency-modulated optically detected magnetic resonance (ODMR) spectra for three different NV orientations and then obtain the Zeeman splittings and the center frequency movement of the electron spin. An artificially generated underlying external magnetic field is used to eliminate degeneracy and facilitate coordinate transformations. The six-channel phase-locked amplification technology enables simultaneous detection of vector magnetic field and temperature with a sensitivity of about 0.87 nT/Hz1/2 and 0.32 mK/Hz1/2; meanwhile, a 23 dB isolation between magnetic and temperature signals is kept. This technology realizes the simultaneous measurement of arbitrary vector magnetic field and temperature, which can be used to study the temperature-varying magnetic phase transition. [ABSTRACT FROM AUTHOR]

Crystal axes must be distinguished in vector magnetic measurements of ensemble nitrogen‐vacancy (NV) centers in diamonds. However, achieving crystal axes distinction in confocal systems without a magnetic bias field is challenging. Thus, a controlled polarized optical excitation method to overcome this problem is proposed. The polarization angle of the excitation beam can be adjusted in free space using an optical pen for higher controllable degrees of freedom. Compared to previous optical excitation methods, the proposed method improves the maximum suppression by 19.2% and the maximum excitation by 42.4%. Moreover, the proposed method has a decoupling effect on NV axis resonances with a similar change trend. This method can easily replace existing optical excitation methods in NV measurement systems and is a powerful tool for ensembles of NV centers' vector measurements without relying on magnetic bias fields. [ABSTRACT FROM AUTHOR]

We study an s-wave superconductivity in a one-dimensional dimerized diamond lattice in the presence of spin–orbit coupling and Zeeman field. The considered diamond lattice, comprising of three sublattices per unitcell and having flat band, has two dimerization patterns; the intra unitcell hoppings have the same (opposite) dimerization pattern as the corresponding inter unitcell hoppings, namely, neighboring (facing) dimerization. Using the mean-field theory, we calculate the superconducting order parameter self-consistently and examine the stability of the superconducting phase against the spin–orbit coupling, Zeeman splitting, dimerization, and temperature. We find that the spin–orbit coupling or Zeeman splitting individually has a detrimental effect on the superconductivity, mostly for the facing dimerization. But their mutual effect revives the superconductivity at charge neutrality point for the facing dimerization. [ABSTRACT FROM AUTHOR]