The effect of spin-orbit interaction on entanglement of two-qubit Heisenberg XYZ systems in an inhomogeneous magnetic field

The role of spin-orbit interaction on the ground state and thermal entanglement of a Heisenberg XYZ two-qubit system in the presence of an inhomogeneous magnetic field is investigated. For a certain value of spin-orbit parameter $D$, the ground state entanglement tends to vanish suddenly and when $D$ crosses its critical value $D_c$, the entanglement undergoes a revival. The maximum value of the entanglement occurs in the revival region. In finite temperatures there are revival regions in $D-T$ plane. In these regions, entanglement first increases with increasing temperature and then decreases and ultimately vanishes for temperatures above a critical value. This critical temperature is an increasing function of $D$, thus the nonzero entanglement can exist for larger temperatures. In addition, the amount of entanglement in the revival region depends on the spin-orbit parameter. Also, the entanglement teleportation via the quantum channel constructed by the above system is investigated and finally the influence of the spin-orbit interaction on the fidelity of teleportation and entanglement of replica state is studied.Comment: Two columns, 9 pages, 8 Fig

Criterion for purely elastic Taylor-Couette instability in the flows of shear-banding fluids

In the past twenty years, shear-banding flows have been probed by various techniques, such as rheometry, velocimetry and flow birefringence. In micellar solutions, many of the data collected exhibit unexplained spatio-temporal fluctuations. Recently, it has been suggested that those fluctuations originate from a purely elastic instability of the flow. In cylindrical Couette geometry, the instability is reminiscent of the Taylor-like instability observed in viscoelastic polymer solutions. In this letter, we describe how the criterion for purely elastic Taylor-Couette instability should be adapted to shear-banding flows. We derive three categories of shear-banding flows with curved streamlines, depending on their stability.Comment: 6 pages, 3 figure

Potential "ways of thinking" about the shear-banding phenomenon

Shear-banding is a curious but ubiquitous phenomenon occurring in soft matter. The phenomenological similarities between the shear-banding transition and phase transitions has pushed some researchers to adopt a 'thermodynamical' approach, in opposition to the more classical 'mechanical' approach to fluid flows. In this heuristic review, we describe why the apparent dichotomy between those approaches has slowly faded away over the years. To support our discussion, we give an overview of different interpretations of a single equation, the diffusive Johnson-Segalman (dJS) equation, in the context of shear-banding. We restrict ourselves to dJS, but we show that the equation can be written in various equivalent forms usually associated with opposite approaches. We first review briefly the origin of the dJS model and its initial rheological interpretation in the context of shear-banding. Then we describe the analogy between dJS and reaction-diffusion equations. In the case of anisotropic diffusion, we show how the dJS governing equations for steady shear flow are analogous to the equations of the dynamics of a particle in a quartic potential. Going beyond the existing literature, we then draw on the Lagrangian formalism to describe how the boundary conditions can have a key impact on the banding state. Finally, we reinterpret the dJS equation again and we show that a rigorous effective free energy can be constructed, in the spirit of early thermodynamic interpretations or in terms of more recent approaches exploiting the language of irreversible thermodynamics.Comment: 14 pages, 6 figures, tutorial revie

Formation of lead lanthanum zirconate titanate films by heat treatments

Lead lanthanum zirconate titanate (PLZT) also called lanthanum doped PZT films were deposited by RF magnetron sputtering. PLZT in the perovskite phase is required to obtain a film with a large electro-optic effect. It can also be used as a ferroelectric and piezoelectric material. However films that have not been heat treated either during or after deposition are typically in the pyrochlore phase. Perovskite PLZT films obtained by heating the substrate during sputtering showed little evidence of cracks in the films sputtered without heating the substrate were not in the Perovskite phase and post deposition annealing was required to do so. Both furnace and rapid thermal annealing were investigated but in both cases cracks formed in the films to various degrees. Such films are unsuitable for optical device fabrication. To determine the orientation of PLZT films X-ray diffraction (XRD) spectras were obtained and compared. Samples were prepared on silicon substrates which had a thin film of 20 nm Ti/100 nm Pt deposited by electron beam evaporation. Sputtering was done in an argon atmosphere using a PLZT (9/65/35) target. Thicknesses of 1 mum were obtained. Some samples were heated during sputtering up to a temperature of 650 degC. Annealing temperatures were varied from 500 to 750 degC. The best results (determined by XRD) were obtained for RTA at 750 degC for 10 minutes in air. XRD spectra of before and after annealing show a significant increase in the Perovskite peaks. The patterning of these films to form optical waveguides by ion beam etching is also presented. The samples were patterned with photoresist masks and ion beam etched using argon at a gun voltage of 500

Review of Fall Injuries and Related Factors in Patients Admitted to a Trauma Referral Hospital in Tehran, Iran

Background: Falls are important causes of mortality and morbidity in urban areas and put a high burden on societies. We investigated patterns of fall traumas and related factors in a referral trauma hospital in Tehran, Iran.Methods: In this routine-data-based study, all documents of fall cases in Hazrate-Rasool hospital, Tehran, Iran, during October 2014-2015 were investigated. Information on demographic factors of patients, fall conditions and outcomes were collected. Data were analyzed by SPSS 11.5. The statistically significant level was considered ≤ 0.05.Results: Of the 307 cases, 70% were male. Median (interquartile range) age was 32 (22-51) years. Of cases, 91% were undergraduates. The mortality rate was 2.6%. Suicide attempts reported in 17 (5.5%) cases and only 2 (12%) of them were successful. Injured body organs in order of frequency were extremities, head and neck, thorax, vertebras, abdomen and pelvis. Outcome (in terms of injured body organs) was related to age and gender of patients alongside with height and reason of the fall. Falls at workplaces, in suicide attempts and among males happened for significantly higher distances. High distance falls and low GCS at admission were related to higher mortality. Majority of falls on a same level happened at home among old women.Conclusion: In our region, fall was a problem of people with low socioeconomic status. Our mortality rate is similar to the highest mortality rates in the world. Personal characteristics along with trauma-related factors are both important in the outcomes of fall cases. Safety equipment at high risk jobs is essential to prevent falls

Elastic turbulence in shear banding wormlike micelles

We study the dynamics of the Taylor-Couette flow of shear banding wormlike micelles. We focus on the high shear rate branch of the flow curve and show that for sufficiently high Weissenberg numbers, this branch becomes unstable. This instability is strongly sub-critical and is associated with a shear stress jump. We find that this increase of the flow resistance is related to the nucleation of turbulence. The flow pattern shows similarities with the elastic turbulence, so far only observed for polymer solutions. The unstable character of this branch led us to propose a scenario that could account for the recent observations of Taylor-like vortices during the shear banding flow of wormlike micelles

Anomalous left brachiocephalic vein: important vascular anomaly concomitant with congenital anomalies and heart diseases

Background: Anomalous left brachiocephalic vein (ALBCV) is a rare and less known systemic venous anomaly. Infrequently, this vein takes an abnormal course and passes to the right behind or beneath the aortic arch to create the superior vena cava (SVC). Its incidence was reported much higher in patients with congenital heart disease especially in conotruncal and aortic arch anomalies. It could be misdiagnosed with normal or abnormal mediastinal structures. It also could make complication during surgeries or invasive strategies. Previously, this anatomical finding has been reported in case reports and there are just few studies evaluating these patients as a group to find other abnormalities Materials and methods: We conducted a retrospective, multicentre study between 2008 and 2014 at three institutions. We reviewed thoracic computed tomography angiography of 1372 patients referred to these centres. The diagnosis of ALBCV was confirmed by an expert radiologist and the imagings were reassessed to identify new cases and concomitant anomalies. We analysed the imagings’ details and measured the prevalence of each anomaly. Results: Among the 22 cases of ALBCV, 12 (54.5%) and 10 (45.4%) patients were males and females, respectively, with median age of 12.5 years. Tetralogy of Fallot (TOF) was considered as a most concomitant anomaly with ALBCV (54.5%). Two patients had associated atrial septal defect (ASD) and defined as pentalogy of Fallot. Right-sided aortic arc (RSAA) was detected in 12 (54.5%) patients; mirror image was found in 5 of them. Pure ventricular septal defect or pulmonary stenosis without TOF was recognised in 4 patients. Three cases had isolated overriding aorta (13.6%). In 3 patients, we could find patent ductus arteriosus (13.6%). In 2 (9%) patients, abdominal haemangioma was incidentally diagnosed. Aberrant left retrotracheal subclavian artery was detected in 1 (4.5%) patient. One patient only had isolated ALBCV (4.5%). Conclusions: In our study, ALBCV was frequently seen in association with other congenital anomalies. mostly TOF and RSAA. In patients with pulmonary hypoplasia or aplasia, some parts of lung’s blood supply were provided by abnormal aorto-pulmonary connections. For a radiologist, it is important to differentiate this anomaly in cross-sectional imaging from persistent left SVC, partial anomalous pulmonary veins return and an enlarged lymph node. Detection of ALBCV could draw the attention to the more serious heart disease and in isolated forms prevented further evaluations.

Interface dynamics in shear-banding flow of giant micelles

We report on a non trivial dynamics of the interface between shear bands following a start-up of flow in a semi-dilute wormlike micellar system investigated using a combination of mechanical and optical measurements. During the building of the banding structure, we observed the stages of formation, migration of the interface between bands and finally the destabilization of this interface along the vorticity axis. The mechanical signature of these processes has been indentified in the time series of the shear stress. The interface instability occurs all along the stress plateau, the asymptotic wavelength of the patterns increasing with the control parameter typically from a fraction of the gap width to about four times the gap width. Three main regimes of dynamics are highlighted : a spatially stable oscillating mode approximately at the middle of the coexistence region flanked by two ranges where the dynamics appears more exotic with propagative and chaotic events respectively at low and high shear rates. The distribution of small particles seeded in the solution strongly suggests that the flow is three-dimensional. Finally, we demonstrate that the shear-banding scenario described in this paper is not specific to our system