Multipartite entanglement and few-body Hamiltonians

We investigate the possibility to obtain higly multipartite-entangled states as nondegenerate eigenstates of Hamiltonians that involve only short-range and few-body interactions. We study small-size systems (with a number of qubits ranging from three to five) and search for Hamiltonians with a Maximally Multipartite Entangled State (MMES) as a nondegenerate eigenstate. We then find conditions, including bounds on the number of coupled qubits, to build a Hamiltonian with a Greenberger-Horne-Zeilinger (GHZ) state as a nondegenerate eigenstate. We finally comment on possible applications.Comment: 15 pages, 3 figures. Proceedings of IQIS 2013 to appear on IJQ

Quantum Typicality and Initial Conditions

If the state of a quantum system is sampled out of a suitable ensemble, the measurement of some observables will yield (almost) always the same result. This leads us to the notion of quantum typicality: for some quantities the initial conditions are immaterial. We discuss this problem in the framework of Bose-Einstein condensates.Comment: 8 page

“Application of Next Generation Technologies in liquid biopsy: focus on Non Small Cell Lung Cancer and Metastatic Colorectal Cancer”

Background: In the precision medicine era, the increasing request of clinical relevant biomarkers to improve the patients management lead to the need of most biological source. To address this issue, also if tissue represents the gold standard for the assessment of clinical relevant biomarkers mutational status, some alternative approaches, based on the analysis of circulating free DNA (cfDNA) extracted from “liquid biopsies”, are under evaluation. The aims of this thesis were to investigate the role of liquid biopsy in two specific settings: analysis of EGFR mutational status in Non Small Cell Lung Cancer (NSCLC) patients treated with EGFR Tyrosine Kinase Inhibitors (TKIs) and as a screening tool for Colorectal Cancer (CRC) in comparison of Fetal Immunochemical Test (FIT). Methods: Regarding EGFR mutational status assessment in NSCLC patients, the analytical sensitivity of SiRe panel, which covers 568 mutations in six genes (EGFR, KRAS, NRAS, BRAF, cKIT and PDGFRα) was validated on cell line DNA and cfDNA derived from cancer patients at presentation (n=42), treatment response (n=12) and tumor progression (n=11) were analyzed; all patients had paired tumor tissue and cfDNA previously genotyped with a Taqman-derived assay (TDA). In addition, we tested blood samples prospectively collected from NSCLC patients (n=79) to assess the performance of SiRe in clinical practice. In relation to CRC patients, employing the analytical validated Real Time PCR-based ColoScape assay kit, mutations in the APC, KRAS, BRAF and CTNNB1 genes were assessed on 52 prospectively collected whole-blood samples obtained from FIT+ patients enrolled in the CRC screening program of ASL NAPOLI 3 SUD, using colonoscopy as confirmation. Results: In relation to the analysis of EGFR mutational status in NSCLC patients treated with EGFR TKIs, SiRe showed high analytical performance and a 0.01% lower limit of detection. Regarding the results obtained in the retrospective series, SiRe was able to detect 40 EGFR, 11 KRAS, 1 NRAS and 5 BRAF mutations (96.8% concordance with TDA). In the baseline sample set, SiRe had 100% specificity and 79% sensitivity relative to results obtained on paired tumor tissue. In the prospective series, SiRe detected 8.7% (4/46) of EGFR mutations at baseline and 42.9% (9/21) of EGFR p.T790M in patients at tumor progression. Regarding the application of Real Time PCR based ColoScape assay kit as a screening tool for CRC patients, the assay's sensitivity for advanced adenomas was 53.8% and the specificity was 92.3%. The Positive Predictive Value was 70.0% and negative predictive value was 85.7%. Of note, four of the six positive cases missed by ColoScape had a less than suboptimal DNA input. Had they been ruled out as inadequate, sensitivity would have increased from 53.8% to 69%. Conclusions: In the landscape of EGFR mutated NSCLC patients treated with TKIs, SiRe represents a feasible NGS panel for cfDNA analysis in clinical practice, while in CRC patients setting, ColoScape is a promising tool for screening program aims to evaluate the triage of FIT+ patients

Correlation Plenoptic Imaging With Entangled Photons

Plenoptic imaging is a novel optical technique for three-dimensional imaging in a single shot. It is enabled by the simultaneous measurement of both the location and the propagation direction of light in a given scene. In the standard approach, the maximum spatial and angular resolutions are inversely proportional, and so are the resolution and the maximum achievable depth of focus of the 3D image. We have recently proposed a method to overcome such fundamental limits by combining plenoptic imaging with an intriguing correlation remote-imaging technique: ghost imaging. Here, we theoretically demonstrate that correlation plenoptic imaging can be effectively achieved by exploiting the position-momentum entanglement characterizing spontaneous parametric down-conversion (SPDC) photon pairs. As a proof-of-principle demonstration, we shall show that correlation plenoptic imaging with entangled photons may enable the refocusing of an out-of-focus image at the same depth of focus of a standard plenoptic device, but without sacrificing diffraction-limited image resolution.Comment: 12 pages, 5 figure

A multisensing setup for the intelligent tire monitoring

The present paper offers the chance to experimentally measure, for the first time, the internal tire strain by optical fiber sensors during the tire rolling in real operating conditions. The phenomena that take place during the tire rolling are in fact far from being completely understood. Despite several models available in the technical literature, there is not a correspondently large set of experimental observations. The paper includes the detailed description of the new multi-sensing technology for an ongoing vehicle measurement, which the research group has developed in the context of the project OPTYRE. The experimental apparatus is mainly based on the use of optical fibers with embedded Fiber Bragg Gratings sensors for the acquisition of the circumferential tire strain. Other sensors are also installed on the tire, such as a phonic wheel, a uniaxial accelerometer, and a dynamic temperature sensor. The acquired information is used as input variables in dedicated algorithms that allow the identification of key parameters, such as the dynamic contact patch, instantaneous dissipation and instantaneous grip. The OPTYRE project brings a contribution into the field of experimental grip monitoring of wheeled vehicles, with implications both on passive and active safety characteristics of cars and motorbikes

Long-lived entanglement of two multilevel atoms in a waveguide

We study the presence of nontrivial bound states of two multilevel quantum emitters and the photons propagating in a linear waveguide. We characterize the conditions for the existence of such states and determine their general properties, focusing in particular on the entanglement between the two emitters, that increases with the number of excitations. We discuss the relevance of the results for entanglement preservation and generation by spontaneous relaxation processes.Comment: 6 pages, 1 figur

Huygens' principle and Dirac-Weyl equation

We investigate the validity of Huygens' principle for forward propagation in the massless Dirac-Weyl equation. The principle holds for odd space dimension n, while it is invalid for even n. We explicitly solve the cases n=1,2 and 3 and discuss generic $n$. We compare with the massless Klein-Gordon equation and comment on possible generalizations and applications.Comment: 7 pages, 1 figur

Correlation plenoptic imaging

Plenoptic imaging is a promising optical modality that simultaneously captures the location and the propagation direction of light in order to enable three-dimensional imaging in a single shot. However, in classical imaging systems, the maximum spatial and angular resolutions are fundamentally linked; thereby, the maximum achievable depth of field is inversely proportional to the spatial resolution. We propose to take advantage of the second-order correlation properties of light to overcome this fundamental limitation. In this paper, we demonstrate that the momentum/position correlation of chaotic light leads to the enhanced refocusing power of correlation plenoptic imaging with respect to standard plenoptic imaging.Comment: 6 pages, 3 figure

Typical observables in a two-mode Bose system

A class of k-particle observables in a two-mode system of Bose particles is characterized by typicality: if the state of the system is sampled out of a suitable ensemble, an experimental measurement of that observable yields (almost) always the same result. We investigate the general features of typical observables, the criteria to determine typicality and finally focus on the case of density correlation functions, which are related to spatial distribution of particles and interference.Comment: 8 pages, 1 figur