Diradicals, molecules with two unpaired electrons, are reactive intermediates that play an important role in many fields. Their defining feature is the energy difference between their singlet and triplet states, which provides direct information on the extent of their electron exchange interactions. Such knowledge is essential for understanding their diradical character, which is controllable i...

We investigate transport through a mononuclear transition-metal complex with strong tunnel coupling to two electrodes. The ground state of this molecule is a singlet, while the first excited state is a triplet. We show that a modulation of the tunnel-barrier due to a molecular distortion which couples to the tunneling induces a Kondo-effect, provided the discrete vibrational energy compensates ...

in this paper, we study the electronic properties of a concentric triple quantum ring using exact diagonalization technique. the energy spectra and magnetization for a single electron and two electrons, in the presence of an applied magnetic field, are calculated and discussed. it is shown that, for two-interacting electrons, the period of aharonov-bohm oscillations decreases to the half of tha...

Rapid coherent control of electron spin states is required for implementation of a spin-based quantum processor. We demonstrated coherent control of electronic spin states in a double quantum dot by sweeping an initially prepared spin-singlet state through a singlet-triplet anticrossing in the energy-level spectrum. The anticrossing serves as a beam splitter for the incoming spin-singlet state....

One of the key effects which is predicted to arise in superconductors without a centre inversion mixing singlet and triplet order parameters, are no longer good quantum numbers on their own due parity. We have probed gap structure noncentrosymmetric superconductor Ru$_7$B$_3$, through small-angle neutron diffraction from vortex lattice, search for proposed mixed parameter. find that measured te...

The effects of ethynyl substitution on the electronic structure of cyclobutadiene are investigated in this work. Ethynyl substituted cyclobutadienes may be involved in Bergman cyclization reactions and are possible intermediates in the formation of fullerenes and graphitic sheets. Prediction of the electronic structure of cyclobutadiene is challenging for single-reference ab initio methods beca...

A new class of singlet superconductors with a gap function ∆(k, ωn) which is odd in both momentum and Matsubara frequency is considered. Some of the physical properties of this superconductivity are discussed and it is argued that: i) the electron-phonon interaction can produce this kind of pairing, ii) in many cases there is no gap in the quasiparticle spectrum, iii) these superconductors will...

The interpretation of the ultrafast luminescence decay in [Re(Br(CO)3(N^N)] complexes as a new group of chromophoric imidazo[4,5-f]-1,10-phenanthroline ligands, including 1,2-dimethoxy benzene, tert-butyl benzene (L4) and 1,2,3-trimethoxy benzene, tert-butyl benzene (L6), was studied. Fac-[Re(Br(CO)3L4 and L6] with different aryl groups were calculated in singlet and triplet excited states. The...

Triplet-state aromaticity has been recently proposed as a strategy for designing functional organic electronic compounds, many of which are polycyclic aromatic systems. However, in cases, the nature triplet state cannot be easily predicted. Moreover, it is often unclear how specific structural manipulations affect properties excited-state compounds. Herein, relationship between structure polybe...

the synthesis, spectroscopic and magnetic characterization of a series of new alkoxo-bridged binuclear copper (ii) compounds are described. all complexes have the general formula [cu (m-or)(l)2]2(clo4)2 · x h2o, in which m-or = ch3o-, c2h5o- or c3h7o-, l = 2-amino-4-methylpyridine (abbreviated a4pic) and 2-amino-5-methylpyridine ( abbreviated a5pic). the title compounds all consist of dinuclear...