1. Theoretical Plasma Physics Group, Department of Physics, Quaid-i-Azam University, Islamabad 45320, Pakistan
2. National Centre for Physics (NCP), Shahdra Valley Road, P.O. Box 2141, Islamabad 44000, Pakistan
3. COMSATS University Islamabad, Islamabad Campus, Park Road, Chak Shahzad, Islamabad 44000, Pakistan
4. The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151 Trieste, Italy