Tunable Rashba spin-orbit interaction at oxide interfaces

The quasi-two-dimensional electron gas found at the LaAlO3/SrTiO3 interface offers exciting new functionalities, such as tunable superconductivity, and has been proposed as a new nanoelectronics fabrication platform. Here we lay out a new example of an electronic property arising from the interfacial breaking of inversion symmetry, namely a large Rashba spin-orbit interaction, whose magnitude can be modulated by the application of an external electric field. By means of magnetotransport experiments we explore the evolution of the spin-orbit coupling across the phase diagram of the system. We uncover a steep rise in Rashba interaction occurring around the doping level where a quantum critical point separates the insulating and superconducting ground states of the system

Seebeck effect in the conducting LaAlO_{3}/SrTiO_{3} interface

The observation of metallic behavior at the interface between insulating oxides has triggered worldwide efforts to shed light on the physics of these systems and clarify some still open issues, among which the dimensional character of the conducting system. In order to address this issue, we measure electrical transport (Seebeck effect, Hall effect and conductivity) in LaAlO_{3}/SrTiO_{3} interfaces and, for comparison, in a doped SrTiO_{3} bulk single crystal. In these experiments, the carrier concentration is tuned, using the field effect in a back gate geometry. The combined analysis of all experimental data at 77 K indicates that the thickness of the conducting layer is ~7 nm and that the Seebeck effect data are well described by a two-dimensional (2D) density of states. We find that the back gate voltage is effective in varying not only the charge density, but also the thickness of the conducting layer, which is found to change by a factor of ~2, using an electric field between -4 and +4MV/m at 77K. No enhancement of the Seebeck effect due to the electronic confinement and no evidence for two-dimensional quantization steps are observed at the interfaces.Comment: 15 pages, 5 figure

Regularity of prime ideals

We answer several natural questions which arise from a recent paper of McCullough and Peeva providing counterexamples to the Eisenbud\u2013Goto Regularity Conjecture. We give counterexamples using Rees algebras, and also construct counterexamples that do not rely on the Mayr\u2013Meyer construction. Furthermore, examples of prime ideals for which the difference between the maximal degree of a minimal generator and the maximal degree of a minimal first syzygy can be made arbitrarily large are given. Using a result of Ananyan-Hochster we show that there exists an upper bound on regularity of prime ideals in terms of the multiplicity alone

Estimation of mean number of daily hand hygiene procedures per patient can represent an effective and easy understandable method to evaluate adherence. Experience in a tertiary care pediatric hospital of Northern Italy

Introduction. Hand decontamination with alcohol-based antiseptic agents is considered  the best practise to reduce healthcare associated infections.Methods. We present a new method to monitor hand hygiene, introduced in a tertiary care pediatric hospital inNorthern Italy, which estimates the mean number of daily hand decontamination procedures performed per patient. The total amount of isopropyl alcohol and chlorhexydine solution supplied in a trimester to each hospital ward was put in relation with the number of hospitalization days, and expressed as liters/1000 hospitalization-days (World Health Organization standard), and the mean number of patients hospitalized and expressed as mean estimated number of hand hygiene procedures per patient per day (new method).Results. The two methods had  similar performance for estimating  the adherence to correct hand disinfection procedures. The new method identified wards and/or periods with high or low  adherence to the procedure and indicated where to perform interventions and their effectiveness. The new methods could result easy-to understand also for non-infection control experts.Conclusion. This method can help non-infection control experts to understand adherence to correct hand- hygiene procedures and improve quality standards

Band inversion driven by electronic correlations at the (111) LaAlO3_3/SrTiO3_3 interface

Quantum confinement at complex oxide interfaces establishes an intricate hierarchy of the strongly correlated $d$-orbitals which is widely recognized as a source of emergent physics. The most prominent example is the (001) LaAlO$_3$/SrTiO$_3$(LAO/STO) interface, which features a dome-shaped phase diagram of superconducting critical temperature and spin-orbit coupling (SOC) as a function of electrostatic doping, arising from a selective occupancy of $t_{2g}$ orbitals of different character. Here we study (111)-oriented LAO/STO interfaces - where the three $t_{2g}$ orbitals contribute equally to the sub-band states caused by confinement - and investigate the impact of this unique feature on electronic transport. We show that transport occurs through two sets of electron-like sub-bands, and the carrier density of one of the sets shows a non-monotonic dependence on the sample conductance. Using tight-binding modeling, we demonstrate that this behavior stems from a band inversion driven by on-site Coulomb interactions. The balanced contribution of all $t_{2g}$ orbitals to electronic transport is shown to result in strong SOC with reduced electrostatic modulation.Comment: 5 pages, 4 figures, (+ supplemental material

Towards Smart Sensing Systems: A New Approach to Environmental Monitoring Systems by Using LoRaWAN

The proliferation of monitoring in unpredictable environments has aided the world in solving challenges that were previously thought to be insurmountable. Drastic advancement has been pinpointed in the way we live, work, and play; however, the data odyssey has yet started. From sensing to monitoring, the endless possibility enabled by LoRa, the long-range low power solution has made its mark on the technological world. With the adoption of the LoRaWAN, the long-range low power wide area network has appeared in existence to cope with the constraints associated with the Internet of Things (IoT) infrastructure. This paper presents a practical experiment for sensing the environmental condition using the LoRaWAN solution. The proposed work allows the users to check the environmental effects (temperature, and humidity) online. Furthermore, the signal behavior has been recorded and cross-verified by using MATLAB software implementation

Two-dimensional superconductivity at the (111)LaAlO3_3/SrTiO3_3 interface

We report on the discovery and transport study of the superconducting ground state present at the (111)LaAlO$_3$/SrTiO$_3$ interface. The superconducting transition is consistent with a Berezinskii-Kosterlitz-Thouless transition and its 2D nature is further corroborated by the anisotropy of the critical magnetic field, as calculated by Tinkham. The estimated superconducting layer thickness and coherence length are 10 nm and 60 nm, respectively. The results of this work provide a new platform to clarify the microscopic details of superconductivity at LaAlO$_3$/SrTiO$_3$ interfaces, in particular in what concerns the link with orbital symmetry.Comment: 4 pages, 4 figure

Enhancing Cyber Security of LoRaWAN Gateways under Adversarial Attacks

The Internet of Things (IoT) has disrupted the IT landscape drastically, and Long Range Wide Area Network (LoRaWAN) is one specification that enables these IoT devices to have access to the Internet. Former security analyses have suggested that the gateways in LoRaWAN in their current state are susceptible to a wide variety of malicious attacks, which can be notoriously difficult to mitigate since gateways are seen as obedient relays by design. These attacks, if not addressed, can cause malfunctions and loss of efficiency in the network traffic. As a solution to this unique problem, this paper presents a novel certificate authentication technique that enhances the cyber security of gateways in the LoRaWAN network. The proposed technique considers a public key infrastructure (PKI) solution that considers a two-tier certificate authority (CA) setup, such as a root-CA and intermediate-CA. This solution is promising, as the simulation results validate that about 66.67% of the packets that are arriving from an illegitimate gateway (GW) are discarded in our implemented secure and reliable solution