arXiv subjects

Muhammad Imran Afzal

Publications and source records attributed to Muhammad Imran Afzal.

4 recordsLinked to original sources

arXiv2016

Localization of states, Bloch wave and quantum phase transitions in SUSY deformed potentials in non-Hermitian optical systems

For the first time, we have observed the annihilation of multiple eigenstates of the parent potentials and redistribution of the energy in the deformed potentials in the system with spontaneously breaking of parity-time symmetry while preserving the SUSY of the system. We have observed that the deformation of the potentials is sensitive to initial conditions. This first experimental observation enables the localization of eigenspectra in lateral space (so-called time) and the localization of eigenstates in longitudinal space in the deformed potentials by experimentally applying the SUSY higher-order transformations on tilted and disordered parent potentials, respectively. The former shows a decrease in the slope of the profile of eigenspectrum (bands) due to the localization in lateral space, while the latter shows an increase in the slope due to localization in longitudinal space. This allows the formation of deterministic bandgaps and Bloch waves while retaining the SUSY. In this configuration, the phase transition emerges naturally in the SUSY deformed potentials, which are revealed as the quantum Zeno effect and a peculiar Anderson localization, respectively. The Anderson localization shows the features of effective amplification and quantum Anti-Zeno effect. The experimental results are in full agreement with the theory of SUSY deformed potentials of higher-order transformations. Besides enhancing the understanding of nature, our results can also provide an experimental platform to originate new classes of effective and synthetic materials, and are also significantly important for unifying the interaction dynamics of condensed matter and photonic systems, and the implementation of universal quantum computation.

physics.optics↗

arXiv2016

Symmetry Breaking of Frequency Comb in Varying Normal Dispersion Fiber Ring Cavity

We build on a previously reported frequency comb of mode spacing 0.136 nm in a fiber ring cavity of varying normal dispersion [1], to generate, for the first time, a frequency comb of mode spacing 0.144 nm centered at 978.544 nm to demonstrate the symmetry-breaking. By controlling the birefringence of the optical cavity through fiber stretching and polarization control, the spacing of the comb lines increases from 0.136 nm to 0.144 nm, and this small change in mode spacing generates very different spectral symmetry-breaking in the frequency comb relative to the frequency comb of mode spacing 0.136 nm. Interestingly, non-uniform depletion of primary modes is also observed. The experimental results are an important contribution in the continuing effort of understanding the dynamics of frequency combs involving large number of modes, nontrivial nonlinear waves and deterministic chaos.

physics.optics↗

arXiv2016

Supersymmetrically bounding of asymmetric states and quantum phase transitions by anti-crossing of symmetric states

Von Neumann and Wigner theorized the bounding and anti-crossing of eigenstates. Experiments have demonstrated that owing to anti-crossing and similar radiation rates, the graphene-like resonance of inhomogeneously strained photonic eigenstates can generate a pseudomagnetic field, bandgaps and Landau levels, whereas exponential or dissimilar rates induce non-Hermicity. Here, we experimentally demonstrate higher-order supersymmetry and quantum phase transitions by resonance between similar one-dimensional lattices. The lattices consisted of inhomogeneous strain-like phases of triangular solitons. The resonance created two-dimensional, inhomogeneously deformed photonic graphene. All parent eigenstates were annihilated. Eigenstates of mildly strained solitons were annihilated at similar rates through one tail and generated Hermitian bounded eigenstates. The strongly strained solitons with positive phase defects were annihilated at exponential rates through one tail, which bounded eigenstates through non-Hermitianally generated exceptional points. However, strongly strained solitons with negative defects were effectively amplified. Supersymmetry was evident, with preservation of the shapes and relative phase differences of the parent solitons. Localizations of energies generated from annihilations of mildly and strongly strained soliton eigenstates were responsible for geometrical (Berry) and topological phase transitions, respectively. Both contributed to generating a quantum Zeno phase, whereas only strong twists generated topological (Anderson) localization. Anti-bunching-like condensation was also observed.

physics.optics↗

arXiv2016

Observations of 't Hooft's sublattices and Dirac's monopole by inhomogeneous phases of solitons

Here, we experimentally generated photonic graphene by resonance of inhomogeneously strained one dimensional lattices of triangular solitons. Where mildly twisted solitons are considered as north and south monopoles, while strongly twisted solitons are considered as defect north monopoles. Weak bounding is observed between the opposite monopoles. Strong bounding occurred between the monopoles with same polarity. Where a defect north monopole is transformed into a flux-like tube. Which generated an optical analogue of the torus sublattice. Bogomolny's vortice-like symmetry is remained intact in all these observations. Dirac's north monopole along with the string is also observed. The results presented in this paper were also described in terms of supersymmetry and quantum phase transitions, and reported in ref[20].

physics.optics↗