6 papers
Lévy-index control of spectral singularities and coherent perfect absorption in non-Hermitian space-fractional quantum mechanics
Vibhav Narayan Singh, Mohammad Umar, Mohammad Hasan +1
We investigate the scattering features of a non-Hermitian rectangular potential within the framework of space-fractional quantum mechanics. Using the Riesz fractional derivative, w…
Effective SU(2) gadget: holonomic walk on higher-order Poincaré sphere
Mohammad Umar, Sarvesh Bansal, Paramasivam Senthilkumaran
In a manner commensurate to the SU(2) gadget for the Poincaré sphere, which involves a combination of two quarter-wave plates and one half-wave plate regardless of their sequentia…
SU(2) gadget for higher-order Poincaré sphere
Mohammad Umar, Paramasivam Senthilkumaran
The combination of two quarter-wave plates and one half-wave plate, regardless of their sequential arrangement, constitutes a well-established universal SU(2) gadget capable of imp…
Mathematics of effective -plate in polarization optics
Mohammad Umar, Paramasivam Senthilkumaran
The -plate is a spatially inhomogeneous SU(2) birefringent optical element that has garnered significant interest due to its ability to mediate the spin-orbit interaction of lig…
Holonomically constrained polarization transformation
Mohammad Umar, P. Senthilkumaran
In polarization optics, various topological constructs, namely Poincaré spheres of different orders, are used to represent uniform and structured polarization distributions. Simil…
SU(2) polarization evolution on higher-order Poincaré sphere by using general -plate
Mohammad Umar, P. Senthilkumaran
This paper investigates the rotational dynamics on the higher-order Poincaré sphere with the use of -plate by exploring three key aspects: the topological condition, the global…