29 research outputs found
Electron spin coherence exceeding seconds in high purity silicon
Silicon is undoubtedly one of the most promising semiconductor materials for
spin-based information processing devices. Its highly advanced fabrication
technology facilitates the transition from individual devices to large-scale
processors, and the availability of an isotopically-purified Si form
with no magnetic nuclei overcomes what is a main source of spin decoherence in
many other materials. Nevertheless, the coherence lifetimes of electron spins
in the solid state have typically remained several orders of magnitude lower
than what can be achieved in isolated high-vacuum systems such as trapped ions.
Here we examine electron spin coherence of donors in very pure Si
material, with a residual Si concentration of less than 50 ppm and donor
densities of per cm. We elucidate three separate mechanisms
for spin decoherence, active at different temperatures, and extract a coherence
lifetime up to 2 seconds. In this regime, we find the electron spin is
sensitive to interactions with other donor electron spins separated by ~200 nm.
We apply a magnetic field gradient in order to suppress such interactions and
obtain an extrapolated electron spin of 10 seconds at 1.8 K. These
coherence lifetimes are without peer in the solid state by several orders of
magnitude and comparable with high-vacuum qubits, making electron spins of
donors in silicon ideal components of a quantum computer, or quantum memories
for systems such as superconducting qubits.Comment: 18 pages, 4 figures, supplementary informatio
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International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis
BackgroundCritical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).MethodsUsing previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.ResultsThe ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.ConclusionThis critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding
国际过敏与鼻科学共识声明 : 变应性鼻炎
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150599/1/ICARPrimaryAuthorCOIForms1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150599/2/ICARSecondaryAuthorCOIForms.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150599/3/ICARPrimaryAuthorCOIForms2.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150599/4/ICARAuthorCOI2017.8.15.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150599/5/alr22073_c.pd