Thermal and magnetic field stability of holmium single atom magnets

We use spin-polarized scanning tunneling microscopy to demonstrate that Ho atoms on magnesium oxide exhibit a coercive field of more than 8 T and magnetic bistability for many minutes, both at 35 K. The first spontaneous magnetization reversal events are recorded at 45 K for which the metastable state relaxes in an external field of 8 T. The transverse magnetic anisotropy energy is estimated from magnetic field and bias voltage dependent switching rates at 4.3 K. Our measurements constrain the possible ground state of Ho single atom magnets to either Jz = 7 or 8, both compatible with magnetic bistability at fields larger than 10 mT.Comment: 4 pages and supplemental informatio

Adsorption Sites of Individual Metal Atoms on Ultrathin MgO(100) Films

We use Ca doping during growth of one and two monolayer thick MgO films on Ag(100) to identify the adsorption sites of individual adatoms with scanning tunneling microscopy. For this we combine atomic resolution images of the bare MgO layer with images of the adsorbates and the substitutional Ca atoms taken at larger tip-sample distance. For Ho atoms, the adsorption sites depend on MgO thickness. On the monolayer, they are distributed on the O and bridge sites according to the abundance of those sites, 1/3 and 2/3 respectively. On the MgO bilayer, Ho atoms populate almost exclusively the O site. A third species adsorbed on Mg is predicted by density functional theory and can be created by atomic manipulation. Au atoms adsorb on the bridge sites for both MgO thicknesses, while Co and Fe atoms prefer the O sites, again for both thickness.Comment: 8 pages, 9 figures, part of the work presented at the DPG Spring meeting in Dresden, 201

Analog MIMO Radio-over-Copper: Prototype and Preliminary Experimental Results

Analog Multiple-Input Multiple-Output Radio-over-Copper (A-MIMO-RoC) is an effective all-analog FrontHaul (FH) architecture that exploits any pre-existing Local Area Network (LAN) cabling infrastructure of buildings to distribute Radio-Frequency (RF) signals indoors. A-MIMO-RoC, by leveraging a fully analog implementation, completely avoids any dedicated digital interface by using a transparent end-to-end system, with consequent latency, bandwidth and cost benefits. Usually, LAN cables are exploited mainly in the low-frequency spectrum portion, mostly due to the moderate cable attenuation and crosstalk among twisted-pairs. Unlike current systems based on LAN cables, the key feature of the proposed platform is to exploit more efficiently the huge bandwidth capability offered by LAN cables, that contain 4 twisted-pairs reaching up to 500 MHz bandwidth/pair when the length is below 100 m. Several works proposed numerical simulations that assert the feasibility of employing LAN cables for indoor FH applications up to several hundreds of MHz, but an A-MIMO-RoC experimental evaluation is still missing. Here, we present some preliminary results obtained with an A-MIMO-RoC prototype made by low-cost all-analog/all-passive devices along the signal path. This setup demonstrates experimentally the feasibility of the proposed analog relaying of MIMO RF signals over LAN cables up to 400 MHz, thus enabling an efficient exploitation of the LAN cables transport capabilities for 5G indoor applications.Comment: Part of this work has been accepted as a conference publication to ISWCS 201

Harnessing the Therapeutic Potential of Antibodies Targeting Connexin Hemichannels

Connexin hemichannels have been implicated in pathology-promoting conditions, including inflammation, numerous widespread human diseases, including cancer and diabetes, and several rare diseases linked to pathological point mutations

Electrically Driven Spin Resonance of 4f Electrons in a Single Atom on a Surface

A pivotal challenge in present quantum technologies lies in reconciling long coherence times with efficient manipulation of the quantum states of a system. Lanthanide atoms, with their well-localized 4f electrons, emerge as a promising solution to this dilemma if provided with a rational design of the manipulation and detection schemes. Here we utilize a scanning tunneling microscope to construct tailored spin structures and perform electron spin resonance on a single lanthanide atom in such a structure. A magnetically coupled structure made of an Erbium and a Titanium atom at sub-nanometer distance enables us to both drive Erbium's 4f electron spins and indirectly probe them through the Titanium's 3d electrons. In this coupled configuration, the Erbium spin states exhibit a four-fold increase in the spin relaxation time and a two-fold increase in the driving efficiency compared to the 3d electron counterparts. Our work provides a new approach to accessing highly protected spin states, enabling us to control them in an all-electric fashion

Anisotropic hyperfine interaction of surface-adsorbed single atoms

Hyperfine interactions between electron and nuclear spins have been widely used in material science, organic chemistry, and structural biology as a sensitive probe to the local chemical environment through spatial identification of nuclear spins. With the nuclear spins identified, the isotropic and anisotropic components of the hyperfine interactions in turn offer unique insight into the electronic ground-state properties of the paramagnetic centers. However, traditional ensemble measurements of hyperfine interactions average over a macroscopic number of spins with different geometrical locations and nuclear isotopes. Here, we use a scanning tunneling microscope (STM) combined with electron spin resonance (ESR) to measure hyperfine spectra of hydrogenated-titanium (Ti) atoms on MgO/Ag(100) and thereby determine the isotropic and anisotropic hyperfine interactions at the single-atom level. By combining vector-field ESR spectroscopy with STM-based atom manipulation, we characterize the full hyperfine tensor of individual Ti-47 and Ti-49 atoms and identify significant spatial anisotropy of hyperfine interaction for both isotopes when they are adsorbed at low-symmetry binding sites. Density functional theory calculations reveal that the large hyperfine anisotropy arises from a highly anisotropic distribution of the ground-state electron spin density. Our work highlights the power of ESR-STM-enabled single-atom hyperfine spectroscopy as a powerful tool in revealing ground-state electronic structures and atomic-scale chemical environments with nano-electronvolt resolution.Comment: 17 pages, 4 figure

Comparing endoscopic and conventional surgery techniques for carpal tunnel syndrome: A retrospective study

Introduction: This study aimed to compare the effectiveness of endoscopic carpal tunnel release (ECTR) versus open carpal tunnel release (OCTR) in treating carpal tunnel syndrome (CTS), focusing on symptom relief, functional recovery and post-operative complications. Methods: A retrospective analysis was conducted on 44 patients diagnosed with CTS, randomly assigned to undergo either ECTR (n=23) or OCTR (n=21). Parameters evaluated included post-operative pain, grip strength, functional status using the Disability of the Arm, Shoulder and Hand (DASH) score and time to return to work. Results: Patients who underwent ECTR demonstrated superior functional recovery and quicker return to daily and work activities compared to those in the OCTR group. Grip strength improvement post-surgery showed no significant difference between the groups. However, ECTR patients reported significantly lower DASH scores and faster return to work, indicating better outcomes. There were fewer reports of post-operative complications and scar sensitivity in the ECTR group. Conclusion: ECTR provides an effective alternative to OCTR for CTS treatment, with advantages in functional recovery speed, reduced post-operative discomfort and faster return to work. These findings support the adoption of ECTR as a preferred surgical approach for CTS, highlighting its potential to improve patient outcomes with minimal complications

Advanced multi-sensor platform for chronic disease home monitoring

Nowadays chronic diseases affect an ever-growing segment of population in developed countries; and the management of such kind of diseases requires a huge amount of resources. Chronic Heart Failure, Chronic Obstructive Pulmonary Disease, Diabetes, etc. are the main causes of hospitalization for elderly people, and considering the general aging of population this may lead sustainability problems in the near future. In the last years, clinicians and administrators have identified the telemedicine as strategy to improve the patient management, ensuring both a decreasing of hospital admissions and improving the patient's quality of life. This paper presents a complete system for the management of the healthcare information related to the chronic patient treatment, integrating three main points: a configurable multi-sensor platform for the acquisition and transmission of vital signs, a dedicated server for the provisioning of centralized telemedicine services and the possibility of synchronizing with the electronic health record