arXiv subjects

E. Londero

Publications and source records attributed to E. Londero.

3 recordsLinked to original sources

arXiv2020

A Case Study of the May 30th, 2017 Italian Fireball

On May 30th, 2017 at about 21h 09m 17s UTC a green bright fireball crossed the sky of north-eastern Italy. The fireball path was observed from some all-sky cameras starting from a mean altitude of $81.1 \pm 0.2$ km (Lat. $44.369^{\circ} \pm 0.002^{\circ}$ N; Long. $11.859^{\circ} \pm 0.002^{\circ}$ E) and extinct at $23.3 \pm 0.2$ km (Lat. $45.246^{\circ} \pm 0.002^{\circ}$ N; Long. $12.046^{\circ} \pm 0.002^{\circ}$ E), between the Italian cities of Venice and Padua. In this paper, on the basis of simple physical models, we will compute the atmospheric trajectory, analize the meteoroid atmospheric dynamics, the dark flight phase (with the strewn field) and compute the best heliocentric orbit of the progenitor body. Search for meteorites on the ground has not produced any results so far.

astro-ph.EP↗

arXiv2018

Identification of nickel-vacancy defect in the photocurrent spectrum of diamond by means of \emph{ab initio} calculations

There is a continuous search for solid-state spin qubits operating at room temperature with excitation in the IR communication bandwidth. Recently we have introduced the photoelectric detection of magnetic resonance (PDMR) to read the electron spin state of nitrogen-vacancy (NV) center in diamond, a technique which is promising for applications in quantum information technology. By measuring photoionization spectra on a diamond crystal we found two ionization thresholds that were not reported before. On the same sample we also observed absorption and photoluminescence signatures that were identified in literature as Ni associated defects. We performed \emph{ab initio} calculation of the photo-ionization cross-section of the nickel split vacancy complex (NiV) and N-related defects in their relevant charge states and fitted the concentration of these defects to the measured photocurrent spectrum, which led to a surprising match between experimental and calculated spectra. This study enabled to identify the two unknown ionization thresholds with the two acceptor levels of NiV. Because the excitation of NiV is in infrared, the photocurrent detected from the paramagnetic NiV color centers is a promising way towards designing a novel type of electrically readout qubits.

cond-mat.mtrl-sci↗

arXiv2016

Enhanced dual-beam excitation photoelectric detection of NV magnetic resonances in diamond

The core issue for the implementation of the diamond NV centre qubits technology is the sensitive readout of NV spin state. We have recently demonstrated the photoelectric detection of NV magnetic resonances (PDMR), anticipated to be faster and more sensitive than optical detection (ODMR). Here we report on a PDMR contrast of 9 % - three times enhanced compared to previous work - on shallow N-implanted diamond. Based on ab-initio modelling, we demonstrate a novel one-photon ionization dual-beam PDMR protocol. We predict that this scheme is significantly less vulnerable to the influence of defects such as substitutional nitrogen.

cond-mat.mes-hall↗