We engineer a system of two strongly confined quantum dots to gain reproducible electrostatic control the spin at zero magnetic field. Coupling in tight ring-shaped potential with tunnel barriers, we demonstrate that an electric field can switch electron ground state between singlet and triplet configuration. Comparing our experimental co-tunneling spectroscopy data full many-body treatment int...

We investigate the use of external time-dependent magnetic field for the control of the quantum states in a two-electron quantum ring. The hyperfine interaction of the confined electrons with surrounding nuclei couples the singlet state with the three triplet states. When the external magnetic field is changed, the singlet ground state becomes degenerate with the triplet states allowing singlet...

Ab initio calculations have been performed on five singlet and five triplet isomers which are minima on the two lowest potential energy surfaces of Ti2H6. We have used single-configuration ROHF as well as multiconfigurational methods, employing triple-ζ with polarization basis sets. Dynamic correlation effects are accounted for using second-order perturbation methods. Staggered and eclipsed C3v...

the combined effect of hydrostatic pressure and temperature on correlation energy in a triplet state of two electron spherical quantum dot with square well potential is computed. the result is presented taking gaas dot as an example. our result shows the correlation energies are i)negative in the triplet state contrast to the singlet state ii) it increases with increase in pressure  iii)further...

They are important chemical intermediates whose spin state dependent chemistry is implicated in a large number of organic reactions [l-4]. An important feature relevant to an understanding of many of their physical and chemical properties is the small energy gap separating the lowest singlet and triplet states. In fact for a number of carbenes these two states are in equilibrium at room tempera...

We have performed time-of-flight neutron scattering measurements on powder samples of the unconventional spin-Peierls compound TiOBr using the fine-resolution Fermi chopper spectrometer (SEQUOIA) at the Spallation Neutron Source at Oak Ridge National Laboratory. These measurements reveal two branches of magnetic excitations within the commensurate and incommensurate spin-Peierls phases, which w...

The global potential energy surfaces of singlet and triplet H2O4 systems have been searched at the B3LYP/ 6-311G(d, p) level of theory; their relative energies have been calculated at the G2M(CC5)// B3LYP/6-311G (d, p) level. The results show that the most stable intermediate out of the 11 open-chain and cyclic dimers of HO2 is the singlet HO4H chain-structure with C1 symmetry which lies 19.1 k...

Ab initio electronic structure theory has been applied to predict the structures and electronic spectra of free-base porphyrin (PH2) and its meso-tetrahalogenated derivatives (m-PX8H2; X = F, Cl, Br). Structures, singlet-triplet energy gaps, and electronic spectra are predicted using the B3LYP method in conjunction with the 6-31G(d) basis set and the effective core potentials/basis sets of Stev...

Optical properties of biphenyl difluoroboron β-diketonates were studied in poly(lactic acid) (PLA) blends. Increased conjugation lowered the emission energy, decreased the singlet-triplet energy gap and yielded blue thermally activated delayed fluorescence (TADF). The properties of these biphenyl dyes may inform organic light emitting diode (OLED) and bioimaging agent design.