Related papers: Spin-structures of N-boson systems with nonzero sp…
The Hamiltonian of a N-boson system confined on a ring with zero spin and repulsive interaction is diagonalized. The excitation of a pair of p-wave-particles rotating reversely appears to be a basic mode. The fluctuation of many of these…
We perform a non-perturbative analysis of the dynamics of a two-level quantum system subjected to repeated interactions with a bosonic environment when these interactions are intense and localized in time. We use the Weyl relations to…
We review recent results on the existence of ground states for the infrared-critical spin boson model, which describes the interaction of a massless bosonic field with a two-state quantum system. Explicitly, we derive a critical coupling…
A system of strongly interacting fermions in a solid state is discussed. A structure of singlet and triplet coupled 2-particle states and their excitation spectra are investigated. It is shown that an account of intersite fermion…
For special coupling ratios, the one-dimensional (1D) s=1/2 Heisenberg model with antiferromagnetic nearest and next-nearest neighbor interactions has a pure dimer ground state, and the 1D s=1 Heisenberg model with antiferromagnetic…
The microscopic control available over cold atoms in optical lattices has opened new opportunities to study the properties of quantum spin models. While a lot of attention is focussed on experimentally realizing ground or thermal states via…
The spin-boson model, describing a two-level system strongly coupled to a bosonic bath, is extensively studied as a paradigmatic dissipative quantum system, exhibiting rich dynamical behavior and even a localization transition in the strong…
We consider a system of interacting non-relativistic bosons confined to a one-dimensional ring in the presence of a synthetic gauge field induced by a rotating barrier. Interactions are introduced as a constraint in field space, and the…
For a two-component bosonic system, the components can be mapped onto a pseudo-spin degree of freedom with spin quantum number S=1/2. We provide a rigorous proof that for a wide-range of real Hamiltonians with component independent mass and…
Ultra-cold alkali atoms trapped in two distinct hyperfine states in an external magnetic field can mimic magnetic systems of spin 1/2 particles. We describe the spin-dependent effective interaction as a spin-spin interaction. As a…
Spin states of two-dimensional Wigner clusters are considered at low temperatures, when all electrons are in ground coordinate states. The spin subsystem behavior is determined by antiferromagnetic exchange integrals. The spin states in…
It is pointed out that the ground state of n neutrons and n protons in a single-j shell, interacting through an isoscalar (T=0) pairing force, is not paired, J=0, but rather spin-aligned, J=n. This observation is explained in the context of…
We study the non-equilibrium dynamics of two component bosonic atoms in a one-dimensional optical lattice in the presence of spin-orbit coupling. In the Mott insulating regime, the two-component bosonic system at unity filling can be…
An enhanced binding of $N$-{\it relativistic} particles coupled to a massless scalar bose field is investigated. It is not assumed that the system has a ground state for the zero-coupling. It is shown, however, that there exists a ground…
We formulate a method to study two-body correlations in a system of N identical bosons interacting via central two-body potentials. We use the adiabatic hyperspherical approach and assume a Faddeev-like decomposition of the wave function.…
We derive the ground-state energy of $N$ composite bosons made of fermion pairs using the recently developed composite boson many-body formalism. We concentrate on the $N$-pair energy linear in density. We show that the scattering relevant…
A general three-dimensional noncommutative quantum mechanical system mixing spatial and spin degrees of freedom is proposed. The analogous of the harmonic oscillator in this description contains a magnetic dipole interaction and the ground…
We consider the nonrelativistic four-boson system in two dimensions interacting via a short-range attractive potential. For a weakly attractive potential with one shallow two-body bound state with binding energy B_2, the binding energies…
The spin-boson model usually considers a spin coupled to a single bosonic bath. However, some physical situations require coupling of the spin to multiple environments. For example, spins interacting with phonons in three-dimensional…
We analyze the effect of a bath of spins interacting with a spin system in terms of the equation of motion technique. We show that this formalism can be used with general spin systems and baths, and discuss the concrete case of a Quantum…