arXiv subjects

M. Javed Akram

Publications and source records attributed to M. Javed Akram.

8 recordsLinked to original sources

arXiv2026

Assessing the Effects of Macroeconomic Variables on Child Mortality in D-8 Countries Using Panel Data Analysis

This research analyses the axiomatic link among health expenditures, inflation rate, and gross national income (GNI) per capita concerning the child mortality (CMU5) rate in D-8 nations, employing panel data analysis from 1995 to 2014. Utilising conventional panel unit root tests and linear regression models, we establish that education expenditures, in conjunction with health expenditures, inflation rate, and GNI per capita, display stationarity at level. Additionally, we examine fixed effects and random effects estimators for the pertinent variables, utilising metrics such as the Hausman Test (HT) and comparisons with CCMR correlations. Our data demonstrate that the CMU5 rate in D-8 nations has steadily decreased, according to a somewhat negative linear regression model, therefore slightly undermining the fourth Millennium Development Goal (MDG4) of the World Health Organisation (WHO).

econ.TH↗

arXiv2017

Quantum noise spectra for periodically-driven cavity optomechanics

A growing number of experimental set-ups in cavity optomechanics exploit periodically driven fields. However, such set-ups are not amenable to analysis using simple, yet powerful, closed-form expressions of linearized optomechanics, which have provided so much of our present understanding of experimental optomechanics. In the present paper, we formulate a new method to calculate quantum noise spectra in modulated optomechanical systems, which we analyze, compare, and discuss with two other recently proposed solutions: we term these (i) frequency-shifted operators (ii) Floquet and (iii) iterative analysis. We prove that (i) and (ii) yield equivalent noise spectra, and find that (iii) is an analytical approximation to (i) for weak modulations. We calculate the noise spectra of a doubly-modulated system describing experiments of levitated particles in hybrid electro-optical traps. We show excellent agreement with Langevin stochastic simulations in the thermal regime and predict squeezing in the quantum regime. Finally, we reveal how experimentally inaccessible spectral components of a modulated system can be measured in heterodyne detection through an appropriate choice of modulation frequencies.

quant-ph↗

arXiv2017

Control of Fano resonances and slow light using Bose-Einstein condensates in a nanocavity

In this study, a standing wave in an optical nanocavity with Bose-Einstein condensate (BEC) constitutes a one-dimensional optical lattice potential in the presence of a finite two bodies atomic interaction. We report that the interaction of a BEC with a standing field in an optical cavity coherently evolves to exhibit Fano resonances in the output field at the probe frequency. The behavior of the reported resonance shows an excellent compatibility with the original formulation of asymmetric resonance as discovered by Fano [U. Fano, Phys. Rev. 124, 1866 (1961)]. Based on our analytical and numerical results, we find that the Fano resonances and subsequently electromagnetically induced transparency of the probe pulse can be controlled through the intensity of the cavity standing wave field and the strength of the atom-atom interaction in the BEC. In addition, enhancement of the slow light effect by the strength of the atom-atom interaction and its robustness against the condensate fluctuations are realizable using presently available technology.

quant-ph↗

arXiv2016

Engineering single-phonon number states of a mechanical oscillator via photon subtraction

We introduce an optomechanical scheme for the probabilistic preparation of single-phonon Fock states of mechanical modes based on photo-subtraction. The quality of the produced mechanical state is confirmed by a number of indicators, including phonon statistics and conditional fidelity. We assess the detrimental effect of parameters such as the temperature of the mechanical system and address the feasibility of the scheme with state-of-the-art technology.

quant-ph↗

arXiv2015

Multiple electromagnetically induced transparency, slow and fast light in hybrid optomechanics

We theoretically investigate the phenomenon of electromagnetically induced transparency (EIT) of a weak probe field in hybrid optomechanics with a single three-level ($Λ$-type) atomic system. We report that, in the presence of optomechanical coupling and two transition coupling parameters of three-level atom (TLA), there occurs three distinct multiple EIT windows in the probe absorption spectrum. Moreover, the switching of multiple windows into double and single EIT windows can be obtained by suitably tuning the system parameters. Furthermore, the probe transmission spectrum have been studied. Based on our analytical and numerical work, we explain the occurrence of slow and fast light (superluminal) regimes, and enhancement of superluminal behaviour in the probe field transmission. This work demonstrates great potential in multi-channel waveguide, fiber optics and classical communication networks, multi-channel quantum information processing, real quality imaging, cloaking devices and delay lines & optical buffers for telecommunication.

quant-ph↗

arXiv2015

Single Phonon State of Mechanical Mode via Photon Subtraction

We prepare single phonon Fock state of mechanical mode in optomechanical system based on photon subtraction process in the linear regime of optomechanical interaction. The correlation set between cavity and field modes is utilized to recast the state of a pre-cooled mechanical mode into a single phonon Fock state as the field mode is subjected to a photon subtraction type measurement at a dynamical instant of interaction time. The resultant conditional state of mechanical mode quantified by its Wigner function, exhibits an excellent compatibility with the standard single quantum Fock state. We confirm the nature of obtained state by calculating the phonon statistics, and conditional fidelity which approaches to unity for an instantaneous measurement time within an appropriate choice of parametric regime. Moreover, we also study the effects of temperature parameter for the preparation of target state. The present scheme can be realized to engineer the single quantum Fock state of macroscopic mechanical mode with currently available technology.

quant-ph↗

arXiv2015

Tunable fast and slow light in a hybrid optomechanical system

We explain the probe field transmission spectrum under the influence of a strong pump field in a hybrid optomechanical system, composed of an optical cavity, a mechanical resonator, and a two-level atom. We show fast (superluminal) and slow (subluminal) light effects of the transmitted probe field in the hybrid system for suitable parametric regimes. For the experimental accessible domain, we find that the fast light effect obtained for the single optomechanical coupling can further be enhanced with the additional atom-field coupling in the hybrid system. Furthermore, we report the existence of a tunable switch from fast to slow light by adjusting the atomic detuning with the anti-Stokes and Stokes sidebands, respectively, as $Δ_a=+ω_m$ and $-ω_m$. The reported characteristics are realizable in state-of-the-art laboratory experiments.

quant-ph↗

arXiv2015

Efficient tunable switch from slow light to fast light in quantum opto-electromechanical system

The control of slow and fast light propagation, in the probe transmission in a single experiment, is a challenging task. This type of control can only be achieved through highly nonlinear interactions and additional interfering pathway(s), which is therefore seldom reported. Here, we devise a scheme in which slow light, and a tunable switch from slow light to fast light can be achieved in the probe transmission based on a hybrid setup, which is composed of an optical cavity with two charged nano mechanical resonators (MRs). The two MRs are electrostatically coupled via tunable Coulomb coupling strength ($g_{c}$) making a quantum opto-electromechanical system (QOEMS). The parameter $g_{c}$ that couples the two MRs can be switched on and off by controlling the bias voltages on the MRs, and acts as a tunable switch that allows the propagation of transmitted probe field as slow light ($g_{c} \neq 0$) or fast light ($g_{c} = 0$). In our scheme, the magnitude of delay and pulse advancement can be controlled by tuning the Coulomb interaction and power of the pump field. Furthermore, we show that slow light regime in our model is astonishingly robust to the cavity decay rate. In comparison with previous schemes, our scheme has clear advantages that empowers the state-of-the-art photonic industry as well as reflects the strength of emerging hybrid technologies.

quant-ph↗