Multi-partite entanglement and quantum phase transition in the one-, two-, and three-dimensional transverse field Ising model

In this paper we consider the quantum phase transition in the Ising model in the presence of a transverse field in one, two and three dimensions from a multi-partite entanglement point of view. Using \emph{exact} numerical solutions, we are able to study such systems up to 25 qubits. The Meyer-Wallach measure of global entanglement is used to study the critical behavior of this model. The transition we consider is between a symmetric GHZ-like state to a paramagnetic product-state. We find that global entanglement serves as a good indicator of quantum phase transition with interesting scaling behavior. We use finite-size scaling to extract the critical point as well as some critical exponents for the one and two dimensional models. Our results indicate that such multi-partite measure of global entanglement shows universal features regardless of dimension $d$. Our results also provides evidence that multi-partite entanglement is better suited for the study of quantum phase transitions than the much studied bi-partite measures.Comment: 7 pages, 8 Figures. To appear in Physical Review

A Comparison of the effectiveness of cooperative and individual teaching methods on educational achievement of English in grade one of high school

The purpose of this study was to compare cooperative teaching and individual teaching on educational achievement in English in grade one of high school (female students). This study is a quasi-experimental study with pre-test- and post- test with two experimental groups. The Statistical population was high school's first grade female students of Mahabad. For sampling, multi-stage cluster sampling was used. The sample size was 52 consist of 25 and 27 members in the experimental group (1) and (2) in which cooperation and individual teaching methods were used respectively. In order to equalize the members of groups the student's GPA were controlled and pre-test and IQ test were done. The results showed no significant difference between groups.The pre-test was a researcher-made. Reliability of the pre-test was obtained 0.83. The cooperative and individual methods were done for 2 months and then post- test was carried out. The results showed no significant differences between them. T-test analyzes shows significant differences between the two groups so that the first experimental group (cooperative) showed better performance in educational achievement

Vibration-enhanced quantum transport

In this paper, we study the role of collective vibrational motion in the phenomenon of electronic energy transfer (EET) along a chain of coupled electronic dipoles with varying excitation frequencies. Previous experimental work on EET in conjugated polymer samples has suggested that the common structural framework of the macromolecule introduces correlations in the energy gap fluctuations which cause coherent EET. Inspired by these results, we present a simple model in which a driven nanomechanical resonator mode modulates the excitation energy of coupled quantum dots and find that this can indeed lead to an enhancement in the transport of excitations across the quantum network. Disorder of the on-site energies is a key requirement for this to occur. We also show that in this solid state system phase information is partially retained in the transfer process, as experimentally demonstrated in conjugated polymer samples. Consequently, this mechanism of vibration enhanced quantum transport might find applications in quantum information transfer of qubit states or entanglement.Comment: 7 pages, 6 figures, new material, included references, final published versio

Adiabatic entanglement transport in Rydberg aggregates

We consider the interplay between excitonic and atomic motion in a regular, flexible chain of Rydberg atoms, extending our recent results on entanglement transport in Rydberg chains [W\"uster et al., Phys.Rev.Lett 105 053004 (2010)]. In such a Rydberg chain, similar to molecular aggregates, an electronic excitation is delocalised due to long range dipole-dipole interactions among the atoms. The transport of an exciton that is initially trapped by a chain dislocation is strongly coupled to nuclear dynamics, forming a localised pulse of combined excitation and displacement. This pulse transfers entanglement between dislocated atoms adiabatically along the chain. Details about the interaction and the preparation of the initial state are discussed. We also present evidence that the quantum dynamics of this complex many-body problem can be accurately described by selected quantum-classical methods, which greatly simplify investigations of excitation transport in flexible chains

Quantum transport in quantum networks and photosynthetic complexes at the steady state

Recently, several works have analysed the efficiency of photosynthetic complexes in a transient scenario and how that efficiency is affected by environmental noise. Here, following a quantum master equation approach, we study the energy and excitation transport in fully connected networks both in general and in the particular case of the Fenna-Matthew-Olson complex. The analysis is carried out for the steady state of the system where the excitation energy is constantly "flowing" through the system. Steady state transport scenarios are particularly relevant if the evolution of the quantum system is not conditioned on the arrival of individual excitations. By adding dephasing to the system, we analyse the possibility of noise-enhancement of the quantum transport.Comment: 10 pages, single column, 6 figures. Accepted for publication in Plos On

Two Challenging Cases with COVID heart

COVID-19 affects the heart through various pathways. It can increase thrombotic complications that ultimately lead to myocardial infarction even in patients without a history of underlying heart disease. © 2020 The Authors. Clinical Case Reports published by John Wiley & Sons Lt

Difficult weaning from cardiopulmonary bypass after surgical VSD closure: An unusual rare case

The connection of the left coronary artery to the pulmonary artery may be asymptomatic due to high pulmonary vascular resistance in the context of left-to-right shunts. Before the repair of the mentioned anomalies, coronary anatomy must be defined. © 2020 The Authors. Clinical Case Reports published by John Wiley & Sons Ltd