236 research outputs found

    Low-Temperature Characteristics of an AlN/Diamond Surface Acoustic Wave Resonator

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    Phonons confined in mechanical resonators can be coupled to a variety of quantum systems and are expected to be applied to hybrid quantum systems. Diamond surface acoustic wave (SAW) devices are capable of high efficiency in phonon interaction with color centers in diamond. The temperature dependence of the quality factor is crucial for inferring the governing mechanism of coupling efficiency between phonons and color centers in diamond. In this paper, we report on the temperature dependence of the quality factor of an AlN/diamond SAW device from room temperature to 5 K. The temperature dependence of the quality factor and resonant frequency suggests that the mechanism of SAW dissipation in the AlN/diamond SAW resonator at 5 GHz is the phonon-phonon scattering in the Akheiser region, and that further cooling can be expected to improve the quality factor. This result provides a crucial guideline for the future design of AlN/diamond SAW devices.Comment: 10 pages, 5 figure

    Coherent Electric-Field Control of Orbital state in a Neutral Nitrogen-Vacancy Center

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    The coherent control of the orbital state is crucial for color centers in diamonds for realizing extremely low-power manipulation. Here, we propose the neutrally charged nitrogen-vacancy center, NV0^0, as an ideal system for orbital control through electric fields. We estimate electric susceptibility in the ground state of NV0^0 to be comparable to that in the excited state of NV^-. Also, we demonstrate coherent control of the orbital states of NV0^0. The required power for orbital control is three orders of magnitude smaller than that for spin control, highlighting the potential for interfacing a superconducting qubit operated in a dilution refrigerator.Comment: 12 pages, 6 figure

    Study on Wash-out of Asphalt Mixture Caused by Repeated Heating and Cooling Immersion Test

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    Stripping generates within the asphalt pavements due to continuous effect of moisture has been one of the concerns by the road authorities worldwide. Without a proper treatment, it could cause potholes and lower the bearing capacity of asphalt pavements. With regard to this, it is well known that the bipolar anti-stripping agent is effective to prevent the stripping due to its electrochemical bonding characteristics between aggregate and asphalt. Wash-out is a dynamic water action that could strip the asphalt mortar from pavement surfacing. Such distress spotted on many roads, whereby, granite aggregates are normally used as the main material in asphalt mixtures. In this study, the experimental work is focused on stripping phenomenon caused by multiple moisture conditioning cycles at 80 °C, and a newly developed evaluation protocol using a Repeated Heating and Cooling Immersion test is adopt-ed. The Wash-out, which is closely associated with stripping, is studied to evaluate the resistance of asphalt pavement against moisture damage. This study is a laboratory scale evaluation and the phenomenon in the field is not yet adequately considered. The repeated heating and cooling immersion procedure is an accelerated strip-ping conditioning without applying an external force. It is clarified that the resistance to the Wash-out of asphalt mixture is improved with the presence of the bi-polar anti-stripping agent, known as Tough Fix Hyper at the rate of 0.15% or more

    Study on Wash-out of Asphalt Mixture Caused by Repeated Heating and Cooling Immersion Test

    Get PDF
    Stripping generates within the asphalt pavements due to continuous effect of moisture has been one of the concerns by the road authorities worldwide. Without a proper treatment, it could cause potholes and lower the bearing capacity of asphalt pavements. With regard to this, it is well known that the bipolar anti-stripping agent is effective to prevent the stripping due to its electrochemical bonding characteristics between aggregate and asphalt. Wash-out is a dynamic water action that could strip the asphalt mortar from pavement surfacing. Such distress spotted on many roads, whereby, granite aggregates are normally used as the main material in asphalt mixtures. In this study, the experimental work is focused on stripping phenomenon caused by multiple moisture conditioning cycles at 80 °C, and a newly developed evaluation protocol using a Repeated Heating and Cooling Immersion test is adopt-ed. The Wash-out, which is closely associated with stripping, is studied to evaluate the resistance of asphalt pavement against moisture damage. This study is a laboratory scale evaluation and the phenomenon in the field is not yet adequately considered. The repeated heating and cooling immersion procedure is an accelerated strip-ping conditioning without applying an external force. It is clarified that the resistance to the Wash-out of asphalt mixture is improved with the presence of the bi-polar anti-stripping agent, known as Tough Fix Hyper at the rate of 0.15% or more

    Extension of the Coherence Time by Generating MW Dressed States in a Single NV Centre in Diamond

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    Nitrogen-vacancy (NV) centres in diamond hold promise in quantum sensing applications. A major interest in them is an enhancement of their sensitivity by the extension of the coherence time (T2T_2). In this report, we experimentally generated more than four dressed states in a single NV centre in diamond based on Autler-Townes splitting (ATS). We also observed the extension of the coherence time to T2T_2 \sim 1.5 ms which is more than two orders of magnitude longer than that of the undressed states. As an example of a quantum application using these results we propose a protocol of quantum sensing, which shows more than an order of magnitude enhancement in the sensitivity.Comment: 8 pages, 9 figure

    Endocrinological Changes after Anamorelin Administration in Patients with Gastrointestinal Cancer

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    Changes in hormone levels in patients with cancer cachexia after anamorelin administration have not been fully investigated. This study aimed to determine how anamorelin affects the endocrine system in patients with gastrointestinal cancer and cachexia. We prospectively enrolled 13 patients and comprehensively investigated their body weight and levels of serum albumin, hemoglobin A1c (HbA1c), and hormones before (week 0) and 3 and 12 weeks after anamorelin administration. The variables were evaluated at week 3 in 9 patients and at week 12 in 5 patients. At week 3, anamorelin administration resulted in body weight gain and increased the levels of growth hormone and HbA1c, as well as insulin-like growth factor-1 standard deviation scores (IGF-1 SD scores). At the same time, negative correlations were observed between ΔIGF-1 SD score and Δthyroidstimulating hormone (TSH) and between ΔIGF-1 SD score and Δfree testosterone. ΔBody weight and ΔIGF-1 SD score correlated positively at week 12. These results suggest that TSH and free testosterone levels can be affected 3 weeks after anamorelin administration; however, those variables tend to return to a state of equilibrium, and anabolic effects of anamorelin appear in long-term (≥ 12 weeks) users
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