Eigenvalues of a potential dynamical system with damping forces that are described by an indefinite real symmetric matrix can behave as those of a Hamiltonian system when gain and loss are in a perfect balance. This happens when the indefinitely damped system obeys parity-time ( ) symmetry. How do pure imaginary eigenvalues of a stable -symmetric indefinitely damped system behave when variation...

We examine the PT-symmetry-breaking transition for a magnetic metamaterial of a finite extent, modeled as an array of coupled split-ring resonators in the equivalent circuit model approximation. Small-size arrays are solved completely in closed form, while for arrays larger than N=5 results were computed numerically for several gain and loss spatial distributions. In all cases, it is found that...

The quantum mechanical brachistochrone system with a PT-symmetric Hamiltonian is Naimark-dilated and reinterpreted as a subsystem of a Hermitian system in a higher-dimensional Hilbert space. This opens a way to a direct experimental implementation of the recently hypothesized PT-symmetric ultrafast brachistochrone regime of Bender et al. [Phys. Rev. Lett. 98, 040403 (2007)] in an entangled two-...

Crystal structures and magnetic properties of polymeric and trinuclear heterobimetallic MnIII···PtII···MnIII coordination compounds, prepared from the Ba[Pt(CN)₄] and [Mn(L4A/B)(Cl)] (1a/b) precursor complexes, are reported. The polymeric complex [{Mn(L4A)}₂{μ⁴-Pt(CN)₄}]n (2a), where H₂L4A = N,N'-ethylene-bis(salicylideneiminate), comprises the {Mn(L4A)} moieties covalently connected through th...

The kinetics of chloride substitution from a series of square-planar platinum(II) complexes, viz. [Pt(terpyridine)Cl](+), (Pt1), [Pt{2-(2'-pyridyl)-1,10-phenanthroline}Cl]Cl, (Pt2), [Pt{4'-(2'''-CH3-phenyl)-2,2':6',2''-terpyridine}Cl]CF3SO3 (Pt3) and [Pt{4'-(2'''-CH3-phenyl)-6-(3''-isoquinoyl)-2,2'bipyridine}Cl]SbF6 (Pt4) were studied using a series of five-membered heterocyclic neutral nitroge...

New square-planar platinum(II) complexes of the type trans-[Pt(PEt3)2(Tx)(X)] (X = Br, Cl, I or CN) bearing a σ-bonded thioxanthon-2-yl (Tx) ligand have been prepared and characterised by X-ray crystallography, cyclic voltammetry, and by NMR and electronic absorption and luminescence spectroscopy. The ligand X hardly influences the electronic transitions, which indicates that the relevant molec...

The primary objective was to understand more deeply the molecular mechanism underlying different antitumor effects of dinuclear Pt(II) complexes containing aromatic linkers of different length, {[cis-Pt(NH(3))(2)Cl](2)(4,4'-methylenedianiline)}(2+) (1) and {[cis-Pt(NH(3))(2)Cl](2)(alpha,alpha'-diamino-p-xylene)}(2+) (2). These complexes belong to a new generation of promising polynuclear platin...