Periodicity is usually assumed to be the necessary and sufficient condition for formation of band gaps, i.e., energy bands with a suppressed density states. Here, we check this premise by analyzing gap properties three structures that differ in degree periodicity ordering. We consider photonic crystal, disordered lattice, ordered but nonperiodic quasicrystalline structure. A real-space metric a...

Modelling of an open quantum system requires knowledge parameters that specify how it couples to its environment. However, beyond relaxation rates, realistic for specific environments and materials are rarely known. Here we present a method inferring the coupling between generic bosonic (e.g., phononic) environment from experimentally measurable density states (DOS). With confirm DOS well-known...

Recently, ground state eigenvectors of the reduced Bardeen–Cooper–Schrieffer (BCS) Hamiltonian, Richardson–Gaudin (RG) states, have been employed as a wavefunction ansatz for strong correlation. This physically represents mean-field pairs electrons (geminals) with constant pairing strength. To move beyond mean-field, one must develop on basis all RG states. requires both practical expressions t...

The major reason for the prediction of thermodynamic properties of mercury lies in the fact that itsintermolecular interactions highly depend on temperature and density. Internal pressure is a good criterion toinvestigate the density dependence of the interatomic interactions. Because its physical base is a forcetending to close together the molecules that is intermolecular interactions, and as...