Coherence of Spin Qubits in Silicon

Given the effectiveness of semiconductor devices for classical computation one is naturally led to consider semiconductor systems for solid state quantum information processing. Semiconductors are particularly suitable where local control of electric fields and charge transport are required. Conventional semiconductor electronics is built upon these capabilities and has demonstrated scaling to large complicated arrays of interconnected devices. However, the requirements for a quantum computer are very different from those for classical computation, and it is not immediately obvious how best to build one in a semiconductor. One possible approach is to use spins as qubits: of nuclei, of electrons, or both in combination. Long qubit coherence times are a prerequisite for quantum computing, and in this paper we will discuss measurements of spin coherence in silicon. The results are encouraging - both electrons bound to donors and the donor nuclei exhibit low decoherence under the right circumstances. Doped silicon thus appears to pass the first test on the road to a quantum computer.Comment: Submitted to J Cond Matter on Nov 15th, 200

A systematic review of community participation measures for people with intellectual disabilities

Background: Community participation is considered a fundamental aspect of quality of life and one of the essential goals of services for people with intellectual disabilities (ID), yet there is no agreed way of measuring community participation. Method: Two systematic searches were performed across eight electronic databases to identify measures of community participation and identify validation studies for each measure. Measures were included if they were developed for adults with ID, measured extent of participation and had published information regarding content and psychometric properties. Each measure was evaluated on the basis of psychometric properties and in relation to coverage of nine domains of community participation from the International Classification of Functioning, Disability and Health (ICF). Results: Eleven measures were selected with the quality rating scores varying substantially ranging from 2-11 of a possible 16. Conclusions: The majority of measures were not sufficiently psychometrically tested. Findings suggest a need for the development of a psychometrically robust instrument

Host isotope mass effects on the hyperfine interaction of group-V donors in silicon

The effects of host isotope mass on the hyperfine interaction of group-V donors in silicon are revealed by pulsed electron nuclear double resonance (ENDOR) spectroscopy of isotopically engineered Si single crystals. Each of the hyperfine-split P-31, As-75, Sb-121, Sb-123, and Bi-209 ENDOR lines splits further into multiple components, whose relative intensities accurately match the statistical likelihood of the nine possible average Si masses in the four nearest-neighbor sites due to random occupation by the three stable isotopes Si-28, Si-29, and Si-30. Further investigation with P-31 donors shows that the resolved ENDOR components shift linearly with the bulk-averaged Si mass.Comment: 5 pages, 4 figures, 1 tabl

Influence of layer microstructure on the double nucleation process in Cu/Mg multilayers

9 páginas, 9 figuras, 3 tablas.-- et al.We have investigated by differential scanning calorimetry the thermal evolution of Cu/Mg multilayers with different modulation lengths, ranging from 7/28 to 30/120 nm. The Cu and Mg layers were grown by sequential evaporation in an electron beam deposition system. The phase identification and layer microstructure were determined by cross-section transmission electron microscopy, Rutherford backscattering, and scanning electron microscopy with focused ion beam for sample preparation. Upon heating, the intermetallic CuMg2 forms at the interfaces until coalescence is reached and thickens through a diffusion-limited process. Cross-section transmission electron microscopy observations show a distinct microstructure at the top and bottom of the as-prepared Mg layers, while no significant differences were seen in the Cu layers. We show that this effect is responsible for the observed asymmetry in the nucleation process between the Cu on Mg and the Mg on Cu interfaces. By modeling the calorimetric data we determine the role of both interfaces in the nucleation and lateral growth stages. We also show that vertical growth proceeds by grain development of the product phase, increasing significantly the roughness of the interfaces.The financial support by Project No. MAT2004-04761 granted by the Spanish Ministry of Education and 2005SGR00201 granted by the Direcció General de Recerca of the Generalitat of Catalonia is acknowledged. One of the authors (J.L.L.) acknowledges the financial support from the Hungarian National Science Fund (OTKA043437).Peer reviewe

Learning From the Implementation of a Surgical Opioid Reduction Initiative in an Integrated Health System: A Qualitative Study Among Providers and Patients

BACKGROUND: Surgical opioid overprescribing can result in long-term use or misuse. Between July 2018 and March 2019, the multicomponent intervention, Minimizing Opioid Prescribing in Surgery (MOPiS) was implemented in the general surgery clinics of five hospitals and successfully reduced opioid prescribing. To date, various studies have shown a positive outcome of similar reduction initiatives. However, in addition to evaluating the impact on clinical outcomes, it is important to understand the implementation process of an intervention to extend sustainability of interventions and allow for dissemination of the intervention into other contexts. This study aims to evaluate the contextual factors impacting intervention implementation. METHODS: We conducted a qualitative study with semi-structured interviews held with providers and patients of the general surgery clinics of five hospitals of a single health system between March and November of 2019. Interview questions focused on how contextual factors affected implementation of the intervention. We coded interview transcripts deductively, using the Consolidated Framework for Implementation Research (CFIR) to identify the relevant contextual factors. Content analyses were conducted using a constant comparative approach to identify overarching themes. RESULTS: We interviewed 15 clinicians (e.g., surgeons, nurses), 1 quality representative, 1 scheduler, and 28 adult patients and identified 3 key themes. First, we found high variability in the responses of clinicians and patients to the intervention. There was a strong need for intervention components to be locally adaptable, particularly for the format and content of the patient and clinician education materials. Second, surgical pain management should be recognized as a team effort. We identified specific gaps in the engagement of team members, including nurses. We also found that the hierarchical relationships between surgical residents and attendings impacted implementation. Finally, we found that established patient and clinician views on opioid prescribing were an important facilitator to effective implementation. CONCLUSION: Successful implementation of a complex set of opioid reduction interventions in surgery requires locally adaptable elements of the intervention, a team-centric approach, and an understanding of patient and clinician views regarding changes being proposed

Si in GaN -- On the Nature of the Background Donor

A characterization of the Si impurity in GaN is performed by Raman spectroscopy. Applying hydrostatic pressure up to 25 GPa the authors study the behavior of the LO phonon-plasmon mode in a series of high mobility Si doped GaN films. In contrast to earlier results on unintentionally doped bulk GaN crystals no freeze out of the free carriers could be observed in Si doped samples. The authors find that Si is a shallow hydrogenic donor throughout the pressure range studied. This result positively excludes Si incorporation as a dominant source of free electrons in previously studied bulk GaN samples

The Development of a Safe Opioid Use Agreement for Surgical Care Using a Modified Delphi Method

BACKGROUND: Opioids prescribed to treat postsurgical pain have contributed to the ongoing opioid epidemic. While opioid prescribing practices have improved, most patients do not use all their pills and do not safely dispose of leftovers, which creates a risk for unsafe use and diversion. We aimed to generate consensus on the content of a safe opioid use agreement for the perioperative settings to improve patients\u27 safe use, storage, and disposal of opioids. METHODS: We conducted a modified three-round Delphi study with clinicians across surgical specialties, quality improvement (QI) experts, and patients. In Round 1, participants completed a survey rating the importance and comprehensibility of 10 items on a 5-point Likert scale and provided comments. In Round 2, a sub-sample of participants attended a focus group to discuss items with the lowest agreement. In Round 3, the survey was repeated with the updated items. Quantitative values from the Likert scale and qualitative responses were summarized. RESULTS: Thirty-six experts (26 clinicians, seven patients/patient advocates, and three QI experts) participated in the study. In Round 1, \u3e75% of respondents rated at least four out of five on the importance of nine items and on the comprehensibility of six items. In Round 2, participants provided feedback on the comprehensibility, formatting, importance, and purpose of the agreement, including a desire for more specificity and patient education. In Round 3, \u3e75% of respondents rated at least four out of five for comprehensibility and importance of all 10 updated item. The final agreement included seven items on safe use, two items on safe storage, and one item on safe disposal. CONCLUSION: The expert panel reached consensus on the importance and comprehensibility of the content for an opioid use agreement and identified additional patient education needs. The agreement should be used as a tool to supplement rather than replace existing, tailored education