Related papers: Quadrupole Arrangements and the Ground State of So…
We study the Coulomb-to-dipole transition which occurs when the separation $d$ of an electron-hole bilayer system is varied with respect to the characteristic in-layer distances. An analysis of the classical ground state configurations for…
We have calculated the crystal electric field of TmTe (T>T_Q) and have obtained that the ground state of a Tm 4f hole is the $\Gamma_7$ doublet in agreement with Mossbauer experiments. We study the quadrupole interactions arising from…
Nuclear quadrupole resonance (NQR) on copper nuclei has been applied for studies of the electronic properties of quasi-two-dimensional low-temperature superconductor CuS (covellite) in the temperature region between 1.47 and 290 K. Two NQR…
The "soft dipole" E1 strength function is calculated for the transition from the $^{6}$He $0^+$ ground state to the $1^-$ continuum $^{4}$He+$n$+$n$. The calculations were performed within the hyperspherical harmonics formalism. The…
In studies of the QCD deconfining phase transition or crossover by means of heavy ion experiments, one ought to be concerned about non-equilibrium effects due to heating and cooling of the system. Motivated by this, we look at hysteresis…
Spectrum and electric dipole transition rates and relative intensities in $^{152-154}$Sm, $^{156-160}$Gd, $^{160-162}$Dy are studied in the framework of the interacting boson model with s,p,d,f bosons. It is found that E1 transition data…
We investigate microscopic aspects of multipole ordering in f-electron systems with emphasis on the effect of lattice structure. For the purpose, first we construct f-electron models on three kinds of lattices, simple cubic (sc), bcc, and…
A combination of state-of-the-art theoretical methods has been used to obtain an atomic-level picture of classical and quantum ordering of protons in cold high-pressure solid hydro-gen. We focus mostly on phases II and III of hydrogen,…
We describe the importance of charge-exchange reactions, and in particular Gamow-Teller transitions, in astrophysical processes and double beta decay, and in understanding of nuclear structure. We first provide an overview of the central…
We study a finite-temperature phase transition in the two-dimensional classical Heisenberg model on a triangular lattice with a ferromagnetic nearest-neighbor interaction $J_1$ and an antiferromagnetic third-nearest-neighbor interaction…
The quadrupole insulator is a well-known instance of higher-order topological insulators in two dimensions, which possesses midgap corner states in both the energy spectrum and entanglement spectrum. Here, by constructing and exploring a…
Hubbard-type models on the hexagonal lattice are of great interest, as they provide realistic descriptions of graphene and other related materials. Hybrid Monte Carlo simulations offer a first-principles approach to study their phase…
We study the interplay between topological and conventional long range order of attractive fermions in a time reversal symmetric Hofstadter lattice using quantum Monte Carlo simulations, focussing on the case of one-third flux quantum per…
The transition quadrupole moments, $Q_{\rm t}$, of four weakly populated collective bands up to spin $\sim$ $65\hbar$ in $^{157,158}$Er have been measured to be ${\sim}11 {\rm eb}$ demonstrating that these sequences are associated with…
We consider a class of {\em quantum Hall topological insulators}: topologically nontrivial states with zero Chern number at finite magnetic field, in which the counter-propagating edge states are protected by a symmetry (spatial or spin)…
Topological phases of electrons such as topological insulators and quantum Hall states typically require strong spin-orbit coupling or magnetic fields. In this study, we consider an electron system coupled to a spin system, where electrons…
Phase transitions associated with nearly conformal dynamics are known to lead to significant supercooling. A notorious example is the phase transition in Randall-Sundrum models or their CFT duals. In fact, it was found that the phase…
In the hydrodynamical description of heavy-ion collisions, the elliptic flow $\mathrm{v_{2}}$ and triangular flow $\mathrm{v_{3}}$ are sensitive to the quadrupole deformation $\mathrm{\beta_{2}}$ of the colliding nuclei. We produce…
The influence of oscillating quadrupole fields on atomic energy levels is examined theoretically and general expressions for the quadrupole matrix elements are given. The results are relevant to any ion-based clock in which one of the clock…
The ground state of an array of coupled, spin-half, antiferromagnetic ladders is studied using spin-wave theory, exact diagonalization (up to 36 sites) and quantum Monte Carlo techniques (up to 256 sites). Our results clearly indicate the…