We study the rise of exceptional points degeneracy (EPD) in various distinct circuit configurations such as gyrator-based coupled resonators, resonators with PT-symmetry, and a single resonator time-varying component. In particular, we analyze their high sensitivity to changes resistance, capacitance, inductance show resonance frequency perturbations. also investigate stability instability cond...

The effects of gain and loss on the band structures a bulk topological dielectric photonic crystal (PC) with ${C}_{6v}$ symmetry PC-air-PC interface are studied based first-principle calculation. To illustrate importance parity-time (PT) symmetry, three systems considered, namely PT-symmetric, PT-asymmetric, lossy systems. We find that system distributed in PT symmetric manner exhibits phase tr...

In the title compound, [Pt(NO(3))(2)(C(42)H(42)O(2)P(4))(2)]·4CH(3)OH, the Pt atom positioned on a crystallographic centre of inversion. The two symmetry-equivalent nitrate anions are weakly coordinated to the Pt(II) ion, creating, together with four P ligand atoms, a distorted octa-hedral coordination environment. In addition, several close C-H⋯O contacts between the nitrate O atoms and phenyl...

We experimentally demonstrate PT-symmetric optical lattices with periodical gain and loss profiles in a coherently prepared four-level N-type atomic system. By appropriately tuning the pertinent atomic parameters, the onset of PT-symmetry breaking is observed through measuring an abrupt phase-shift jump between adjacent gain and loss waveguides. The experimental realization of such a readily re...

The Feshbach-type reduction of the Hilbert space to the physically most relevant “model” subspace is suggested as a means of a formal unification of the standard quantum mechanics with its recently proposed PT symmetric modification. The resulting “effective” Hamiltonians Heff(E) are always Hermitian, and the two alternative forms of their energy-dependence are interpreted as a certain dynamica...

In the title compound, (C(24)H(20)As)[Pt(C(4)F(6)S(2))(2)], the cation lies on a twofold rotation axis while the anion has crystallographic inversion symmetry. The Pt(II) ion is in a slightly distorted square-planar coordination environment. The F atoms of both unique -CF(3) groups are disordered over two sets of sites, the ratios of refined occupancies being 0.677 (15):0.323 (15) and 0.640 (16...

In the mononuclear title complex, [Pt(C(7)H(7))(2)(C(8)H(12))], the Pt(II) ion exhibits a square-planar coordination geometry defined by two methyl-phenyl ligands and the mid-points of the two π-coordinated double bonds of cyclo-octa-1,5-diene. The two methyl-phenyl groups have a cis relationship with a C-Pt-C bond angle of 88.54 (18)° and a dihedral angle between the mean planes of the benzene...

The concept of point interactions offers one of the most suitable guides towards a quantitative analysis of properties of certain specific non-Hermitian (so called PT −symmetric) quantum-mechanical systems. This is illustrated on a double-well model, an easy solvability of which is shown to lead to a clear picture of the mechanisms of the unavoided level crossing and of the spontaneous PT symme...

We study the effect of lifting the degeneracy of vortex modes with a parity time (PT) symmetric defect, using discrete vortices in a circular array of nonlinear waveguides as an example. When the defect is introduced, the degenerate linear vortex modes spontaneously break PT symmetry and acquire complex eigenvalues, but nonlinear propagating modes with real propagation constants can still exist...

By applying the higher order Darboux algorithm to an exactly solvable non Hermitian PT symmetric potential, we obtain a hierarchy of new exactly solvable non Hermitian PT symmetric potentials with real spectra. It is shown that the symmetry underlying the potentials so generated and the original one is nonlinear pseudo supersymmetry. We also show that this formalism can be used to generate a la...