We perform quantum-mechanically exact calculations of resonances in the spectrum of the hydrogen atom in crossed external fields and establish a close connection between the classical transition state in phase space and features in the quantum spectrum. By varying the external field strengths, structures are revealed which are surprisingly similar to the quantized energy levels of the classical...

Continuation of the discussion on semi-classical issues from two weeks ago following John Barret's talk. Main Issue that came up two weeks ago: • In semi-classical considerations: 1) is it adequate to focus on states represented by just a few simplices with faces which have large areas (i.e., dual graphs whose edges have large j values); or, 2) Must we consider states with lots of edges with lo...

Semi-classical states in homogeneous loop quantum cosmology (LQC) are constructed by two different ways. In the first approach, we firstly construct an exponentiated annihilation operator. Then a kind of semiclassical (coherent) state is obtained by solving the eigen-equation of that operator. Moreover, we use these coherent states to analyze the semiclassical limit of the quantum dynamics. It ...

There are some precipitates that undergo transition from a coherent to semi-coherent state during growth. An example of such a precipitate in steel is carbide with a NaCl-type structure, such as TiC and NbC. The interface energy between carbide precipitate and iron is obtained via large-scale first-principles electronic structure calculation. The strain energy is estimated by structure optimiza...

We have numerically studied the statics and dynamics of a model three-dimensional ~3D! vortex lattice at low magnetic fields. For the statics we use a frustrated 3D XY model on a stacked triangular lattice. We model the dynamics as a coupled network of overdamped resistively shunted Josephson junctions with Langevin noise. At low fields, there is a weakly first-order phase transition, at which ...

In this paper we develop a theory of mesoscopic fluctuations in disordered thin superconducting films in a parallel magnetic field. At zero temperature and sufficiently strong magnetic field the system undergoes a phase transition into a state characterized by a superfluid density, which is random in sign. Consequently, in this region, random supercurrents are spontaneously created in the groun...

using hartree-fock su-sheriffer-heeger (hf-ssh) model, we have studied the dependence of the energies of the ground (magnetic triplet state) and the first exited (nonmagnetic singlet state) states of the size-2 trigonal zigzag graphene nanoflake (size-2 nf) on the intensity of an external in plane static electric field at zero temperature. we identify a transition from the magnetic triplet stat...

The purpose of this note is to point out that Karlin and McGregor’s integral representation for the transition probabilities of a birth-death process on a semi-infinite lattice with an absorbing bottom state remains valid if one allows the possibility of absorption into the bottom state from any other state. Conditions for uniqueness of the minimal transition function are also given.