A large solvent polarity effect on the rate of singlet to triplet intersystem crossing (ksT) has been observed in the carbenes, diphenylcarbene (DPC) and dicycloheptadienylidene (DCHD)it is found that both ksT and the energy splitting (A&T) separtaing the singlet and triplet states decrease as the solvent polarity increases for the aromatic carbenes. This “inverse” gap effect, i.e. the time for...

The potential energy curve describing the fragmentation of a diatomic dication ABZ+ is considered as arising from an avoided crossing between an attractive diabatic curve (correlating with A' + B) and a repulsive diabatic curve (correlating with A+ + B'). The simplest avoided-crossing (AC) model neglects diabatic coupling and polarization and leads to useful predictions of the transition struct...

We consider the Born-Oppenheimer problem near conical intersection in two dimensions. For energies close to the crossing energy we describe the wave function near an isotropic crossing and show that it is related to generalized hypergeometric functions 0 F 3. This function is to a conical intersection what the Airy function is to a classical turning point. As an application we calculate the ano...

The phenomenon of the dark energy transition between the quintessence regime (w > −1) and the phantom regime (w < −1), also known as the cosmological constant boundary crossing, is analyzed in terms of the dark energy equation of state. It is found that the dark energy equation of state in the dark energy models which exhibit the transition is implicitly defined. The generalizations of the the ...

We investigate the nonlinearity-assisted quantum tunnelling and formation of nonlinear collective excitations in a matter-wave interferometer, which is realized by the adiabatic transformation of a double-well potential into a singlewell harmonic trap. In contrast to the linear quantum tunnelling induced by the crossing (or avoided crossing) of neighbouring energy levels, the quantum tunnelling...

Thermodynamics second law and ω = −1 crossing(s) in interacting holographic dark energy model Abstract By the assumption that the thermodynamics second law is valid, we study the possibility of ω = −1 crossing in an interacting holographic dark energy model. Depending on the choice of the horizon and the interaction, the transition from quintessence to phantom regime and subsequently from phant...

A transition between energy levels at an avoided crossing is known as a Landau–Zener transition. When a two-level system (TLS) is subject to periodic driving with sufficiently large amplitude, a sequence of transitions occurs. The phase accumulated between transitions (commonly known as the Stückelberg phase) may result in constructive or destructive interference. Accordingly, the physical obse...

* corresponding author. Phone: +46855378030 Email: [email protected] In this work, Fluorescence Correlation Spectroscopy (FCS) was used to investigate the effects of potassium iodide (KI) on the electronic state population kinetics of a range of organic dyes in the visible wavelength range. Apart from a heavy atom effect promoting intersystem crossing to the triplet states in all dyes...

The time–dependent Born–Oppenheimer approximation describes the quantum mechanical motion of molecular systems. This approximation fails if a wavepacket propagates through an electron energy level crossing or “avoided crossing.” We discuss the various types of crossings and avoided crossings and describe what happens when molecular systems propagate through them. It is not practical to solve th...

Thermodynamics second law and ω = −1 crossing(s) in interacting holographic dark energy model Abstract By the assumption that the thermodynamics second law is valid, we study the possibility of ω = −1 crossing in an interacting holographic dark energy model. Depending on the choice of the horizon and the interaction, the transition from quintessence to phantom regime and subsequently from phant...