Asymmetric broadcasting of quantum correlations

In this work, we exhaustively investigate $1 \rightarrow 2$ local and nonlocal broadcasting of entanglement as well as correlations beyond entanglement (geometric discord) using asymmetric Pauli cloners with most general two qubit state as the resource. We exemplify asymmetric broadcasting of entanglement using Maximally Entangled Mixed States. We demonstrate the variation of broadcasting range with the amount of entanglement present in the resource state as well as with the asymmetry in the cloner. We show that it is impossible to optimally broadcast geometric discord with the help of these asymmetric Pauli cloning machines. We also study the problem of $1 \rightarrow 3$ broadcasting of entanglement using non-maximally entangled state (NME) as the resource. For this task, we introduce a method we call successive broadcasting which involves application of $1 \rightarrow 2$ optimal cloning machines multiple times. We compare and contrast the performance of this method with the application of direct $1 \rightarrow 3$ optimal cloning machines. We show that $1 \rightarrow 3$ optimal cloner does a better job at broadcasting than the successive application of $1 \rightarrow 2$ cloners and the successive method can be beneficial in the absence of $1 \rightarrow 3$ cloners. We also bring out the fundamental difference between the tasks of cloning and broadcasting in the final part of the manuscript. We create examples to show that there exist local unitaries which can be employed to give a better range for broadcasting. Such unitary operations are not only economical, but also surpass the best possible range obtained using existing cloning machines enabling broadcasting of lesser entangled states. This result opens up a new direction in exploration of methods to facilitate broadcasting which may outperform the standard strategies implemented through cloning transformations.Comment: Edited sections, changed figures, to be published in Physical Review

Impact of Auditory Verbal Therapy in Children with Cochlear Implant

Introduction Auditory Verbal Therapy (AVT) is considered as most successful therapeutic approach for cochlear implant children. The impact of auditory verbal therapy has been studied vividly in Indian context. The number of cochlear implantees receiving AVT has been increased nationwide but there is no structured protocol that is used to assess the efficacy of AVT on children with cochlear implant. Hence, it is important to develop a structured protocol consisting of established tools to study the effectiveness of AVT. Materials and Methods          The study was conducted on 62 (male-38, female-24) bilaterally profound sensorineural hearing impaired children with cochlear implant done under ADIP (Assistance to Disabled Persons for Purchase/ Fitting of Aids and Appliances) scheme. Pre-therapy assessments were done before 2 weeks of cochlear implantation using Functional Auditory Performance Indicator (FAPI), Assessment of language development, Speech intelligibility rating scales, Brown’s (1973) stages of mean length of utterance (MLU) assessment, and Overall rating of parental satisfaction on a visual analog scale of 0 to 10. Auditory verbal therapy (AVT) was given for 6-8 months, twice per week under video-monitoring of the sessions. Post therapeutic scores were obtained by assessing with the same tools through observation and interaction with the children and interviewing the caregivers.  Results Independent Sample’s T-test in SPSS -16 software were used and significant differences between pre and post therapy scores were obtained (p<0.005). Conclusion These tools can be used further as a protocol for assessment of baseline skills before AVT, then develop an individualized management program and finally to assess the improvement after AVT