We present a framework in which the transition between many-body localized (MBL) phase and an ergodic one is symmetry breaking. consider random Floquet spin chains, expressing their averaged spectral form factor (SFF) as function of time terms transfer matrix that acts space direction. The SFF determined by leading eigenvalues this matrix. In MBL phase, eigenvalue unique, symmetry-unbroken whil...

We investigate signatures of a self-trapping transition in the driven-dissipative Bose Hubbard dimer, presence incoherent pump and single-particle losses. For fully symmetric couplings stationary state density matrix is independent any Hamiltonian parameter, cannot therefore capture competition between hopping-induced delocalization interaction-dominated regime. focus instead on exact quantum d...

The delocalization of the photoexcited triplet state in a linear butadiyne-linked porphyrin dimer is investigated by time-resolved and pulse electron paramagnetic resonance (EPR) with laser excitation. The transient EPR spectra of the photoexcited triplet states of the porphyrin monomer and dimer are characterized by significantly different spin polarizations and an increase of the zero-field s...

Novel DNA base pair derivatives (A2CunU, A2CunC, G3CunU, and G3CunC) are designed by aromatic expansion of pyrimidine bases with four kinds of hetero-rings (denoted by nC and nU, n = 1, 2, 3, and 4) and metal-decoration through Cu replacement of hydrogens in the Watson-Crick hydrogen bond region. Their structures and properties are calculated for examining the cooperative effects of the two mod...

Molecular aromaticity in the linear polyacenes is investigated using an atoms in molecules based six center index (SCI-AIM) which measures the electron delocalization. SCI-AIM values for the linear polyacenes indicate decreasing aromaticity going from outer to inner rings in the polyacene series. The SCI-AIM approach is compared to a Mulliken-like approach, and a critical comparison to the PDI ...