Proton-neutron symplectic model description of $^{20}$Ne

A microscopic description of the low-lying positive-parity rotational bands in $^{20}$Ne is given within the framework of the symplectic-based proton-neutron shell-model approach provided by the proton-neutron symplectic model (PNSM). For this purpose a model Hamiltonian is used which includes an algebraic interaction, lying in the enveloping algebra of the $Sp(12,R)$ dynamical group of the PNSM, that introduces both horizontal and vertical mixings of different $SU(3)$ irreducible representations within the $Sp(12,R)$ irreducible collective space of $^{20}$Ne. A good overall description is obtained for the excitation energies of the ground and first two excited $\beta$ bands, as well as for the ground state intraband $B(E2)$ quadrupole collectivity and the known interband $B(E2)$ transition probabilities between the low-lying collective states without the use of an effective charge.

Orbital selectivity in the normal state of KFe(2)Se(2) superconductor

Using density functional dynamical mean-field theory, we show how correlation effects lead to pseudogap and Kondo-quasiparticle features in the electronic structure of pure and doped KFe2Se2 superconductor. Therein, correlation- and doping-induced orbital differentiation are linked to the emergence of an incoherent-coherent crossover in the normal state of KFe2Se2 superconductor. This crossover explains the puzzling temperature and doping dependent evolution of resistivity and Hall coefficient, seen in experiments of alkali-metal intercalated iron-selenide superconductors. Our microscopic description emphasises the role of incoherent and coherent electronic excitations towards unconventional transport responses of strange, bad-metals.

Thermodynamics as a consequence of mechanics

In this paper the transition from the microscopic description to macroscopic one is considered. Transformation of Mechanics into Thermodynamics follows as its consequence. Retardation of interactions and their role in irreversibility of both theories are analyzed. The mechanical analogue of entropy is found.

Microscopic entropy of AdS3 black holes revisited

We revisit the microscopic description of AdS3 black holes in light of recent progress on their higher dimensional analogues. The grand canonical partition function that follows from the AdS3/CFT2 correspondence describes BPS and nearBPS black hole thermodynamics. We formulate an entropy extremization principle that accounts for both the black hole entropy and a constraint on its charges, in close analogy with asymptotically AdS black holes in higher dimensions. We are led to interpret supersymmetric black holes as ensembles of BPS microstates satisfying a charge constraint that is not respected by individual states. This interpretation provides a microscopic understanding of the hitherto mysterious charge constraints satisfied by all BPS black holes in AdS. We also develop thermodynamics and a nAttractor mechanism of AdS3 black holes in the nearBPS regime.

Progress in the microscopic description of nucleon-nucleus elastic scattering at low-energy

In this brief report, we make a short review of progress in developing the microscopic optical potential in recent years. In particular, we present our current studies and plans on building the microscopic optical potential based on the so-called nuclear structure models at low energies.

Optical Spectroscopy of Crystal Nucleation One Nucleus at a Time

<p>Crystallization is an important process in a wide range of disciplines from fundamental science to industrial application. Despite the importance of controlling the crystallization and its morphology (<i>e.g.</i> polymorphism), the lack of microscopic description of crystal nucleation often limits the rational approach to its engineering and control. The biggest challenge to experimentally track the nucleus formation is the stochastic and heterogeneous nature of the nucleation occurring at nanometer scale. To overcome this challenge, we developed a method we call “Single Nucleus Spectroscopy” or SNS and use it to follow the formation of single crystal glycine nucleus by Raman spectroscopy at 46 ms time resolution. The spectral evolution was analyzed by non-supervised spectral decomposition algorithm which unraveled the Raman spectrum of prenucleation aggregates. In order to gain microscopic insights into the structure of these aggregates we have established a direct comparison between the experiments and theoretical works. The outcome of our analysis is a new hypothesis of glycine crystal nucleation mechanism.<br></p>