The dimethylammonium salt of the FeII polyanionic trimer [Fe3(μ-L)6(H2O)6]6 ́ (L = 4-(1,2,4-triazol-4-yl)ethanedisulfonate) exhibits a thermally induced spin transition above room temperature with one of the widest hysteresis cycles observed in a spin crossover compound (>85 K). Furthermore, the metastable high-spin (HS) state can be thermally trapped via relatively slow cooling, remaining metas...

We present a first principle scheme to compute the rigidity, i.e., the shear-modulus of structural glasses at finite temperatures using the cloned liquid theory, which combines the replica theory and the liquid theory. With the aid of the replica method which enables disentanglement of thermal fluctuations in liquids into intra-state and inter-state fluctuations, we extract the rigidity of meta...

All nanostructures are metastable--but some are more metastable than others. Here we employ aberration-corrected electron microscopy and atomistic computer simulations to demonstrate the hierarchy of metastability in deposited, size-selected gold nanoparticles (clusters), an archetypal class of nanomaterials well known for the catalytic activity which only appears on the nanometer-scale. We sho...

The spectroscopic properties of a single, tightly trapped atom are studied, when the electronic levels are coupled by three laser fields in an N-shaped configuration of levels, whereby a Λ-type level system is weakly coupled to a metastable state. We show that depending on the laser frequencies the response can be tuned from coherent population trapping at two-photon resonance to novel behaviou...

We present a new measurement of the s-wave scattering length a of spin-polarized helium atoms in the 2(3)S1 metastable state. Using two-photon photoassociation spectroscopy and dark resonances, we measure the energy E(nu)=14= -91.35+/- 0.06 MHz of the least-bound state nu = 14 in the interaction potential of the two atoms. We deduce a value of a=7.512+/-0.005 nm, which is at least 100 times mor...

Using recent mathematical advances, a geometric approach to rare noise-driven transition events in nonequilibrium systems is given, and an algorithm for computing the maximum likelihood transition curve is generalized to the case of state-dependent noise. It is applied to a model of electronic transport in semiconductor superlattices to investigate transitions between metastable electric field ...

We study the influence of complex graphs on the metastability and fixation properties of a set of evolutionary processes. In the framework of evolutionary game theory, where the fitness and selection are frequency dependent and vary with the population composition, we analyze the dynamics of snowdrift games (characterized by a metastable coexistence state) on scale-free networks. Using an effec...

The present highlight reviews recent advances in first-principles modelling of radiation damage in UO2. It focuses on the influence of strong correlations and the problem of metastable states that occur with some approximations that localize electrons, in particular the density functional theory (DFT)+U approximation. It gives an illustration that DFT+U calculations quantitatively describe atom...