Primary thermometry triad at 6 mK in mesoscopic circuits

Quantum physics emerge and develop as temperature is reduced. Although mesoscopic electrical circuits constitute an outstanding platform to explore quantum behavior, the challenge in cooling the electrons impedes their potential. The strong coupling of such micrometer-scale devices with the measurement lines, combined with the weak coupling to the substrate, makes them extremely difficult to thermalize below 10 mK and imposes in-situ thermometers. Here we demonstrate electronic quantum transport at 6 mK in micrometer-scale mesoscopic circuits. The thermometry methods are established by the comparison of three in-situ primary thermometers, each involving a different underlying physics. The employed combination of quantum shot noise, quantum back-action of a resistive circuit and conductance oscillations of a single-electron transistor covers a remarkably broad spectrum of mesoscopic phenomena. The experiment, performed in vacuum using a standard cryogen-free dilution refrigerator, paves the way toward the sub-millikelvin range with additional thermalization and refrigeration techniques.Comment: Article and Supplementar

Wigner and Kondo physics in quantum point contacts revealed by scanning gate microscopy

Quantum point contacts exhibit mysterious conductance anomalies in addition to well known conductance plateaus at multiples of 2e^2/h. These 0.7 and zero-bias anomalies have been intensively studied, but their microscopic origin in terms of many-body effects is still highly debated. Here we use the charged tip of a scanning gate microscope to tune in situ the electrostatic potential of the point contact. While sweeping the tip distance, we observe repetitive splittings of the zero-bias anomaly, correlated with simultaneous appearances of the 0.7 anomaly. We interpret this behaviour in terms of alternating equilibrium and non-equilibrium Kondo screenings of different spin states localized in the channel. These alternating Kondo effects point towards the presence of a Wigner crystal containing several charges with different parities. Indeed, simulations show that the electron density in the channel is low enough to reach one-dimensional Wigner crystallization over a size controlled by the tip position

A prospective, randomised comparison of continuous paravertebral block and continuous intercostal nerve block for post-thoracotomy pain

Background: This study aimed to compare paravertebral block and continuous intercostal nerve block after thoracotomy.Methods: Forty-six adult patients undergoing elective posterolateral thoracotomy were randomised to receive either a continuous intercostal nerve blockade or a paravertebral block. Opioid consumption and postoperative pain were assessed for 48 hours .Pulmonary function was assessed by forced expiratory volume in 1 s (FEV1) recorded at 4 hours intervals.Results: With respect to the objective visual assessment (VAS), both techniques were effective for post thoracotomy pain. The average VAS score at rest was 29±10mm for paravertebral block and 31.5±11mm for continuous intercostal nerve block. The average VAS score on coughing was 36±14mm for the first one and 4 ±14mm for the second group. Pain at rest was similar in both groups. Pain scores on coughing were lower in paravertebral block group at 42 and 48 hours. Post-thoracotomy function was better preserved with paravertebral block. No difference was found among the two groups for side effects related to technique, major morbidity or duration of hospitalisation.Conclusion: We found that continuous intercostal nerve block and paravertebral block were effective and safe methods for post-thoracotomy pain.

Effects of moderate- vs. high-intensity interval training on physical fitness, enjoyment, and affective valence in overweight/obese female adolescents: a pre-/post-test study

OBJECTIVE The aim of this study was to compare the effects of 12-week moderate-intensity interval training (MIIT) vs. high-intensity interval training (HIIT) on body composition, physical fitness, and psychological valence in overweight/obese (OW/OB) female adolescents. PATIENTS AND METHODS Thirty-eight OW/OB female students were randomized into HIIT (n=13), MIIT (n=13) or control (n=12) groups. The participants underwent a 12-week interval-training program at 100% to 110% and 60% to 75% of maximal aerobic speed for HIIT and MIIT, respectively. The control group kept their usual physical activity without completing the training program. Pre- and post-training measurements were performed to assess body composition, aerobic capacity, and anaerobic performance (using selected tests evaluating speed, jumping ability, and strength). Ratings of perceived exertion and the feeling scale were evaluated every three weeks. Enjoyment was measured at the end of the program. A two-way analysis of variance with repeated measurements was applied to test for "group×time" interactions for body composition, physical fitness, and affective variables. RESULTS Significant "group×time" interactions were detected for aerobic and anaerobic performance, body composition indices, and the feeling scale. HIIT resulted in more noticeable improvements in body composition and physical performance than MIIT, while no significant changes were found in the control group. Throughout the program, the feeling score has progressively increased in the MIIT group but decreased in the HIIT group. Ratings of the perceived exertion have increased in both groups, more noticeably in the HIIT group. At the end of the program, the MIIT group showed a higher enjoyment score. CONCLUSIONS Despite offering better body composition improvement and physical fitness enhancement, HIIT offered lesser enjoyment and affective valence than MIIT in OW/OB female adolescents. MIIT might be an alternative time-efficient protocol for improving health in this population

Report of the JRC’s Descriptor 2 workshop in support to the review of the Commission Decision 2010/477/EU concerning MSFD criteria for assessing Good Environmental Status for NIS

The MSFD workshop on non-indigenous species (NIS, MSFD D2), held in Ispra JRC (10th-11th of September 2015) aimed to provide clear proposals and conclusions on some of the outstanding issues identified in the D2 review manual (May 2015 consultation version: D2 review manual: https://circabc.europa.eu/sd/a/cd4bbd6a-454a-40db-b805-52fb195d4e56/COMDEC_Review_D2_V6.pdf) in the broader context of support to the review of Commission Decision 2010/477/EU. This report is complementing the Commission Decision 2010/477/EU review manual (JRC96884) and presents the result of the scientific and technical review concluding phase 1 of the review of the Commission Decision 2010/477/EU in relation to Descriptor 2. The review has been carried out by the EC JRC together with experts nominated by EU Member States, and has considered contributions from the GES Working Group in accordance with the roadmap set out in the MSFD implementation strategy (agreed on at the 11th CIS MSCG meeting). The main issues addressed and tackled in this workshop’s report are: - Proposed changes in D2 assessment criteria; - Indicators and methodological standards; - GES threshold values and reference points; - Way forwar

Heteroepitaxial growth of ferromagnetic MnSb(0001) films on Ge/Si(111) virtual substrates

Molecular beam epitaxial growth of ferromagnetic MnSb(0001) has been achieved on high quality, fully relaxed Ge(111)/Si(111) virtual substrates grown by reduced pressure chemical vapor deposition. The epilayers were characterized using reflection high energy electron diffraction, synchrotron hard X-ray diffraction, X-ray photoemission spectroscopy, and magnetometry. The surface reconstructions, magnetic properties, crystalline quality, and strain relaxation behavior of the MnSb films are similar to those of MnSb grown on GaAs(111). In contrast to GaAs substrates, segregation of substrate atoms through the MnSb film does not occur, and alternative polymorphs of MnSb are absent

Vanadyl phthalocyanines on graphene/SiC(0001): toward a hybrid architecture for molecular spin qubits

Vanadyl phthalocyanine (VOPc) contains a highly coherent spin S = ½, which is of interest for applications in quantum information. Preservation of long coherence times upon deposition on conductive materials is crucial for use of single-spin in devices. Here, we report a detailed investigation of the structural, electronic and magnetic properties of a hybrid architecture constituted by a monolayer film of VOPc molecules deposited on graphene/SiC(0001). Graphene (Gr) is a two-dimensional conductor with exceptional chemical stability, a property which we exploited here to preserve the spin of VOPc. Low temperature-scanning tunneling microscopy supported by density functional theory (DFT) simulations revealed that VOPc molecules were adsorbed intact on the Gr/SiC(0001) surface in a planar geometry assuming a unique configuration in which the vanadyl group is projected out toward the vacuum, different to that found commonly on other conductive surfaces. Furthermore, X-ray photoelectron spectroscopy and UV-photoelectron spectroscopy (flanked theoretically by DFT) showed that VOPc interact weakly with the Gr/SiC(0001) substrate to preserve its electronic configuration with the unpaired electron located on the V ion. These findings were confirmed by X-ray magnetic circular dichroism, revealing that the S = ½ character of the VOPc assembly on Gr/SiC(0001) was preserved, in agreement with the theoretical prediction. Hence, molecules could be adsorbed and used as qubits on substrates of technological importance, such as graphene. This new hybrid architecture could be employed for local investigation of static and dynamic spin properties and as molecular qubits for spintronic applications

Metamaterial superlenses operating at visible wavelength for imaging applications

© 2018 The Authors. Published by Nature. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1038/s41598-018-33572-yIn this paper, a novel design for a metamaterial lens (superlens) based on a Photonic Crystal (PC) operating at visible wavelengths is reported. The proposed superlens consist of a gallium phosphide (GaP) dielectric slab waveguide with a hexagonal array of silver rods embedded within the GaP dielectric. In-house 2DFDTD numerical method is used to design and optimize the proposed superlens. Several superlenses are designed and integrated within a same dielectric platform, promoting the proof-of-concept (POC) of possible construction of an array of superlenses (or sub-lenses to create an M-Lens) for light field imaging applications. It is shown that the concavity of the superlens and positioning of each sub-lens within the array strongly affects the performances of the image in terms of resolution. Defects and various geometrical shapes are introduced to construct and optimize the proposed superlenses and increase the quality of the image resolution. It is shown that the orientation of the active region (ellipse) along x and y axis has tremendous influence on the quality of image resolution. In order to investigate the performance characteristics of the superlenses, transmitted power is calculated using 2D FDTD for image projections at various distances (in x and y plane). It is also shown, how the proposed superlens structures could be fabricated using standard micro fabrication techniques such as electron beam lithography, inductively coupled Reactive ion etching, and glancing angle evaporation methods. To the best of our knowledge, these are the first reported POC of superlenses, integrated in a monolithic platform suitable for high imaging resolution that can be used for light field imaging applications at visible wavelength. The proposed superlenses (integrated in a single platform M-Lens) will have tremendous impact on imaging applications