181 research outputs found
Translational dynamics effects on the non-local correlations between two atoms
A pair of atoms interacting successively with the field of the same cavity
and exchanging a single photon, leave the cavity in an entangled state of
Einstein-Podolsky-Rosen (EPR) type (see, for example, [S.J.D. Phoenix, and S.M.
Barnett, J. Mod. Opt. \textbf{40} (1993) 979]). By implementing the model with
the translational degrees of freedom, we show in this letter that the
entanglement with the translational atomic variables can lead, under
appropriate conditions, towards the separability of the internal variables of
the two atoms. This implies that the translational dynamics can lead, in some
cases, to difficulties in observing the Bell's inequality violation for massive
particles.Comment: 5 pages, 1 figur
On the observability of Bell's inequality violation in the optical Stern-Gerlach model
Using the optical Stern-Gerlach model, we have recently shown that the
non-local correlations between the internal variables of two atoms that
successively interact with the field of an ideal cavity in proximity of a nodal
region are affected by the atomic translational dynamics. As a consequence,
there can be some difficulties in observing violation of the Bell's inequality
for the atomic internal variables. These difficulties persist even if the atoms
travel an antinodal region, except when the spatial wave packets are exactly
centered in an antinodal point.Comment: 5 pages, 1 figure, submitted to European Physical Journal
Irreversible decay of nonlocal entanglement via a reservoir of a single degree of freedom
Recently, it has been realized that nonlocal disentanglement may take a
finite time as opposite to the asymptotic decay of local coherences. We find in
this paper that a sudden irreversible death of entanglement takes place in a
two atom optical Stern-Gerlach model. In particular, the one degree non
dissipative environment here considered suddenly destroys the initial
entanglement of any Bell's states superposition.Comment: 6 pages, 4 figures, improved presentation, v2: title changed,
references added, accepted for publication in Phys. Rev. A (Fundamental
concepts
The non dissipative damping of the Rabi oscillations as a "which-path" information
Rabi oscillations may be viewed as an interference phenomenon due to a
coherent superposition of different quantum paths, like in the Young's two-slit
experiment. The inclusion of the atomic external variables causes a non
dissipative damping of the Rabi oscillations. More generally, the atomic
translational dynamics induces damping in the correlation functions which
describe non classical behaviors of the field and internal atomic variables,
leading to the separability of these two subsystems. We discuss on the
possibility of interpreting this intrinsic decoherence as a "which-way"
information effect and we apply to this case a quantitative analysis of the
complementarity relation as introduced by Englert [Phys. Rev. Lett.
\textbf{77}, 2154 (1996)].Comment: 5 pages, 2 figure
The new covid-19 related psychological distress pandemic
Although a few years have passed since the beginning of the COVID-19 pandemic, a large body of scientific literature is already present on the impact that the worldwide spread of the virus has had on people's quality of life [...]
Collective atomic effects in resonance fluorescence
We suggest that the statistical properties of the scattered radiation in resonance-fluorescence experiments may be affected significantly by the existence of atomic correlations. The scattered light spectrum from two- and three-atom collective systems has been calculated and compared with the one-atom spectrum. The differences are quite significant for weak fields, but become less pronounced as the intensity of the driving field is increased. In addition, we have calculated the scattered intensity correlation function for collectively interacting systems, and found that its behavior is very different from that of the single-atom intensity correlation function, both for weak and strong incident fields. The implications of our findings for the observation of photon antibunching are also discussed
Visual Tracking Based on Human Feature Extraction from Surveillance Video for Human Recognition
A multimodal human identification system based on face and body recognition may be made available for effective biometric authentication. The outcomes are achieved by extracting facial recognition characteristics using several extraction techniques, including Eigen-face and Principle Component Analysis (PCA). Systems for authenticating people using their bodies and faces are implemented using artificial neural networks (ANN) and genetic optimization techniques as classifiers. Through feature fusion and scores fusion, the biometric systems for the human body and face are merged to create a single multimodal biometric system. Human bodies may be identified with astonishing accuracy and effectiveness thanks to the SDK for the Kinect sensor. To identify people, biometrics aims to mimic the pattern recognition process. In comparison to traditional authentication methods based on secrets and tokens, it is a more dependable and safe option. Human physiological and behavioral traits are used by biometric technologies to identify people automatically. These characteristics must fulfill many criteria, especially those that relate to universality, efficacy, and applicability
Do mental health and vitality mediate the relationship between perceived control over time and fear of COVID-19? A survey in an Italian sample
Several studies evidenced increased elevated symptomatology levels in anxiety, general stress, depression, and post-traumatic stress related to COVID-19. Real difficulties in the effective control of time that could be responsible for mental health issues and loss of vitality were also reported. Prior literature highlighted how perceived control over time significantly modulates anxiety disorders and promotes psychological well-being. To verify the hypothesis that perceived control over time predicts fear of COVID-19 and mental health and vitality mediate this relationship, we performed an online survey on a sample of 301 subjects (female = 68%; Mage = 22.12, SD = 6.29; age range = 18–57 years), testing a parallel mediation model using PROCESS macro (model 4). All participants responded to self-report measures of perceived control over time, COVID-19 fear, mental health, and vitality subscales of the Short-Form-36 Health Survey. Results corroborate the hypotheses of direct relationships between all the study variables and partially validate the mediation’s indirect effect. Indeed, mental health (a1b1 = −0.06; CI: LL = −0.11; UL = −0.01; p < 0.001) rather than vitality (a2b2 = −0.06; CI: LL = −0.09; UL = 0.03; n.s.) emerges as a significant mediator between perceived control over time and fear of COVID-19. Practical implications of the study about treatment programs based on perceived control over time and emotional coping to prevent fear and anxiety toward the COVID-19 pandemic are discussed
Quantum erasure within the Optical Stern-Gerlach Model
In the optical Stern-Gerlach effect the two branches in which the incoming
atomic packet splits up can display interference pattern outside the cavity
when a field measurement is made which erases the which-way information on the
quantum paths the system can follow. On the contrary, the mere possibility to
acquire this information causes a decoherence effect which cancels out the
interference pattern. A phase space analysis is also carried out to investigate
on the negativity of the Wigner function and on the connection between its
covariance matrix and the distinguishability of the quantum paths.Comment: 7 pages, 3 figure
Adjunctive clotiapine for the management of delusions in two adolescents with anorexia nervosa
Clotiapine is an atypical antipsychotic indicated for the management of a series of acute psychotic disorders. The current literature lacks evidence concerning the tolerability and clinical use of this drug in the management of individuals with anorexia nervosa (AN). In this study, we report two cases of adolescents with AN, treated with clotiapine. The reason for the administration of clotiapine was, for both patients, the manifestation of bizarre delusions concerning food and calories. Patient 1 presented a presyncope after the first dose of clotiapine, and treatment was rapidly discontinued. Patient 2 was treated with clotiapine for 9 months; doses were titrated from 20 mg/day to 70 mg/day, with an improvement in the reported delusions, which also enhanced compliance with psychological and nutritional interventions. EKG, QTc, white blood count, and red blood count were not relevantly influenced by the introduction of clotiapine in either patient. No extrapyramidal effect was documented. These reports stress the need for further studies assessing the tolerability and potential effect of clotiapine in treating adolescents with AN and delusional symptomatology
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