Photon-Photon Correlations as a Probe of Vacuum Induced Coherence Effects

We present new experimental implications of the effects of vacuum induced coherence on the photon -photon correlation in the pi-polarized fluorescence in j = 1/2 to j = 1/2 transition. These effects should be thus observable in measurements of photon statistics in for example Hg and Ba ion traps.Comment: 7 pages, 6 figures, submitted to Physical Review

Reanalysis of Agelietti Procedure (A Method of Corrective Supracondylar Femoral Osteotomy)

Objective: Supracondylar femoral osteotomy is the time tested method, used for correcting the angular (varus & valgus) deformities at the knee. Traditionally, Coventry type of osteotomy where a medial or lateral based wedge of bone is removed or an open wedge osteotomy is made & the space filled with bone graft, is done to achieve the desired correction. This osteotomy is subsequently stabilized with Kirschner wires or plates & screws. Later the limb is externally supported in brace or plaster cast. Here we present a case series of 10 cases, where we have analyzed the efficacy of Aglietti procedure, as a method of femoral supracondylar osteotomy for correcting the valgus deformity at the knee. Methods: Ten valgus adolescent knees were operated in 7 patients by following the Aglietti procedure for correcting the angular deformity at the knee. The results were analyzed taking into consideration the operating time, blood loss during surgery estimated by the number of surgical mops used, stability of the osteotomy in the post-operative period & ultimate range of motion (ROM) obtained at the end of 6 months after the surgery. Results: The average age of patients dealt with was 12.6 years (n=7) with females predominating (n=5) against 2 males. The average time was 47.5 minutes. The average size of the surgical mops used was 15x20 cms. Surgical mops used per patient were 1.6. The average range of flexion achieved at the end of 6 months after surgery was 131.45 degrees ( Rounded average to a measurable value being 131 degrees). Conclusion: In our case series we found Aglietti procedure as an effective method to correct the valgus deformity in adolescent knees. Supracondylar femoral osteotomies are not only for varus an valgus corrections; this osteotomy is used as well for rotation correction and flexion and extension correction, mainly in CP patients. But we used the Agelietti procedure for the correction of angular deformities(varus/valgus) in patients of nutritional rickets. However more number of cases need to be done to make a final conclusion of establishing the superiority of this method over other methods

Inseparability inequalities for higher-order moments for bipartite systems

There are several examples of bipartite entangled states of continuous variables for which the existing criteria for entanglement using the inequalities involving the second order moments are insufficient. We derive new inequalities involving higher order correlation, for testing entanglement in non-Gaussian states. In this context we study an example of a non-Gaussian state, which is a bipartite entangled state of the form $\psi(x_{\rm a},x_{\rm b})\propto (\alpha x_{\rm a}+\beta x_{\rm b})e^{-(x_{\rm a}^2+x_{\rm b}^2)/2}$. Our results open up an avenue to search for new inequalities to test entanglement in non-Gaussian states.Comment: 7 pages, Submitte

Nonclassical Correlation of Polarization Entangled Photons in a Biexciton-Exciton Cascade

We develop a theoretical model to study the Intensity-Intensity correlation of polarization entangled photons emitted in a biexciton-exciton cascade. We calculate the degree of correlation and show how polarization correlation are affected by the presence of dephasing and energy level splitting of the excitonic states. Our theoretical calculations are in agreement with the recent observation of polarization dependent Intensity-Intensity correlations from a single semiconductor quantum dot [R. M. Stevenson et. al., Nature 439, 179 (2006)] . Our model can be extended to study polarization entangled photon emission in coupled quantum dot systems

Mesoscopic superpositions of states - approach to classicality and diagonalization in coherent state basis

I consider the interaction of a superposition of mesoscopic coherent states and its approach to a mixed state as a result of a suitably controlled environment. I show how the presence of a gain medium in a cavity can lead to diagonalization in coherent state basis in contrast to the standard model of decoherence. I further show how the new model of decoherence can lead to the generation of $s$ ordered quasi distributions.Comment: 10 pages, two figure pages, RevTe

Nanomechanical Inverse Electromagnetically Induced Transparency and Confinement of Light in Normal modes

We demonstrate the existence of the phenomenon of the inverse electromagnetically induced transparency (IEIT) in an opto mechanical system consisting of a nanomechanical mirror placed in an optical cavity. We show that two weak counter-propagating identical classical probe fields can be completely absorbed by the system in the presence of a strong coupling field so that the output probe fields are zero. The light is completely confined inside the cavity and the energy of the incoming probe fields is shared between the cavity field and creation of a coherent phonon and resides primarily in one of the polariton modes. The energy can be extracted by a perturbation of the external fields or by suddenly changing the $Q$ of the cavity.Comment: 10 pages, 5 figure