Evidence for topological band inversion of the phase change material Ge2Sb2Te5

We present an angle-resolved photoemission study of a ternary phase change material, namely Ge2Sb2Te5, epitaxially grown on Si(111) in the metastable cubic phase. The observed upper bulk valence band shows a minimum at Gamma-bar being 0.3 eV below the Fermi level E_F and a circular Fermi contour around Gamma-bar with a dispersing diameter of 0.27-0.36 Anstroms^-1. This is in agreement with density functional theory calculations of the Petrov stacking sequence in the cubic phase which exhibits a topological surface state. The topologically trivial cubic KH stacking shows a valence band maximum at Gamma in line with all previous calculations of the hexagonal stable phase exhibiting the valence band maximum at Gamma for a trivial Z_2 topological invariant nu_0 and away from Gamma for non-trivial nu_0. Scanning tunneling spectroscopy exhibits a band gap of 0.4 eV around E_F

Picosecond strain dynamics in Ge2_{2}Sb2_{2}Te5_{5} monitored by time-resolved x-ray diffraction

Coherent phonons (CP) generated by laser pulses on the femtosecond scale have been proposed as a means to achieve ultrafast, non-thermal switching in phase-change materials such as Ge$_{2}$Sb$_{2}$Te$_{5}$(GST). Here we use ultrafast optical pump pulses to induce coherent acoustic phonons and stroboscopically measure the corresponding lattice distortions in GST using 100 ps x-ray pulses from the ESRF storage ring. A linear-chain model provides a good description of the observed changes in the diffraction signal, however, the magnitudes of the measured shifts are too large to be explained by thermal effects alone implying the presence of transient non-equilibrium electron heating in addition to temperature driven expansion. The information on the movement of atoms during the excitation process can lead to greater insight into the possibilities of using CP-induced phase-transitions in GST.Comment: 7 pages, 4 figures, Phys. Rev. B, in pres

Large spin shuttling oscillations enabling high-fidelity single qubit gates

Semiconductor quantum dots have shown impressive breakthroughs in the last years, with single and two qubit gate fidelities matching other leading platforms and scalability still remaining a relative strength. However, due to qubit wiring considerations, mobile electron architectures have been proposed to facilitate upward scaling. In this work, we examine and demonstrate the possibility of significantly outperforming static EDSR-type single-qubit pulsing by taking advantage of the larger spatial mobility to achieve larger Rabi frequencies and reduce the effect of charge noise. Our theoretical results indicate that fidelities are ultimately bottlenecked by spin-valley physics, which can be suppressed through the use of quantum optimal control, and we demonstrate that, across different potential regimes and competing physical models, shuttling based single-qubit gates retain significant advantage over existing alternatives.Comment: 11 Pages, 5 figure

TULA DUAL: Trans Urethral Laser Ablation of recurrent bladder tumors in outpatient setting

To the Editor, Bladder cancer (BCa) is the second most common cancer in urological clinical practice, after prostate adenocarcinoma. Usually occurs in patients between 60 and 70 years old, three times more frequently in men than women. About 75% of bladder cancer are pTa or pT1, even more frequently considering a population younger than 40 years old. Early detection is of paramount importance since allows to find tumors when they are still superficial and therefore with a better prognosi

Mirror-symmetric Magneto-optical Kerr Rotation using Visible Light in [(GeTe)2(Sb2Te3)1]n Topological Superlattices

Interfacial phase change memory (iPCM), that has a structure of a superlattice made of alternating atomically thin GeTe and Sb2Te3 layers, has recently attracted attention not only due to its superior performance compared to the alloy of the same average composition in terms of energy consumption but also due to its strong response to an external magnetic field (giant magnetoresistance) that has been speculated to arise from switching between topological insulator (RESET) and normal insulator (SET) phases. Here we report magneto-optical Kerr rotation loops in the visible range, that have mirror symmetric resonances with respect to the magnetic field polarity at temperatures above 380 K when the material is in the SET phase that has Kramers-pairs in spin-split bands. We further found that this threshold temperature may be controlled if the sample was cooled in a magnetic field. The observed results open new possibilities for use of iPCM beyond phase-change memory applications

Penile lenghthening original technique using a pubo-cavernous spacer. Long term results from a series of over 200 patients

Introduction: We report our long experience in the surgical treatment of patients requesting penile lengthening by suspensory ligament release and placement of a custom-made soft silicone pubo-cavernous spacer. The aim was to show that with this surgical technique the results obtained are maintained over time. It is crucial to achieve postoperative satisfaction of these patients who show fragility and self-esteem problems. Methods: From 1999 to 2020, we treated 245 patients with congenital or acquired penile brevity. We carefully analysed the preoperative and postoperative (at 6, 12, 24 and 48 months) penile size of the patients to evaluate whether this technique could allow the long-term maintenance of aesthetic results. We also assessed preoperative erectile function and we focused on the psychological aspects to avoid surgery in patients with dysmorphophobia. This original technique involves the section of the suspensory ligament and the implantation of a silicone spacer between the pubic symphysis and the corpora cavernosa. This spacer is conformed to the patient anatomy and maintains the relationship between the anatomical structures unchanged over time. Sexual self-esteem and patient satisfaction were assessed with the APPSSI questionnaire. Results: The mean increase in penile length was about 2.5 cm in flaccid state and 1.9 cm in stretched state. There were no injuries of the neurovascular bundle or urethra, and no erectile dysfunction was noted. These results persisted at 6, 12, 24 and 48 months without significant differences. Over 80% of patients stated that they were completely satisfied with the results obtained. This satisfaction remained stable along follow up. Conclusion: The section of the suspensory ligament and the implant of the soft silicone spacer provide real penis elongation with satisfactory results that persist over time. This technique avoids the frequent complication of short-term shortening due to the scar adhesions of the edges of the dissected ligament. The high aesthetic satisfaction of patients is stable at controls at 6, 12, 24 and 48 months

Office-based management of non-muscle invasive bladder cancer (NMIBC): a position paper on current state of the art and future perspectives

To the Editor, Bladder cancer is one of the most common cancers in humans, representing the 7th and 17th type of neoplasm in both genders. Its incidence and mortality are quite heterogeneous in different countries and are due to different risk factors, quality and prevalence of healthcare and the possibility of early diagnosis and treatment of the tumor and its potential recurrences. [...

Geohazard features of the north-western Sicily and Pantelleria

9 pages, 3 figures, supplemental material https://doi.org/10.1080/17445647.2024.2342931.-- Data availability statement: Department of Earth and Marine Science of the University of Palermo for institutional purposes, so their access will be available by contacting the reference people (attilio.sulliunipa.it) upon reasonable requestWe present maps of geohazard features identified across north-western Sicily and Pantelleria in the framework of the Magic project (MArine Geohazard along Italian Coasts), which involved Italian marine geological researchers in 2007-2013. These seafloor features were recognized using high-resolution bathymetry data and rely on the morphological expression of the seafloor and shallow sub-surface processes. The north-western Sicily is a complex continental margin, affected by morphodynamic, depositional, and tectonic processes. The Egadi offshore is controlled by fault escarpments and alternating retreating and progradational processes. Ustica and Pantelleria submerged edifices show the effect of volcanic activity. The Ustica seafloor is interested in volcanic, tectonic, and gravitational instability processes, while the Pantelleria offshore underwent erosive-depositional processes and the effect of bottom currents. Two levels of interpretation are represented: the physiographic domain at a scale of 1:250.000 and the morphological units and morpho-bathymetric elements at a 1:100.000 scaleThe Magic Project has been funded by the Italian Civil Protection Department. [...] With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)Peer reviewe