scholarly journals Quasi-one-dimensional bosons in three-dimensional traps: From strong-coupling to weak-coupling regime

2005 ◽  
Vol 72 (2) ◽  
Author(s):  
L. Salasnich ◽  
A. Parola ◽  
L. Reatto
Keyword(s):  
Strong Coupling ◽  
Weak Coupling ◽  
Three Dimensional ◽  
Weak Coupling Regime ◽  
One Dimensional

PHASE DIAGRAM OF ONE-DIMENSIONAL t–U–J MODEL WITH ANISOTROPIC ANTIFERROMAGNETIC EXCHANGE

2010 ◽  
Vol 24 (28) ◽  
pp. 2769-2783 ◽  
Author(s):  
HANQIN DING ◽  
YANSHEN WANG
Keyword(s):  
Phase Diagram ◽  
Weak Coupling ◽  
Density Wave ◽  
Spin Density Wave ◽  
Spin Excitation ◽  
Antiferromagnetic Exchange ◽  
Weak Coupling Regime ◽  
One Dimensional ◽  
Bond Charge ◽  
Umklapp Scattering

By using the bosonization approach and the weak-coupling renormalization group (RG) techniques, we study the phase diagram of one-dimensional half-filled t–U–J model parametrized by exchange anisotropy λ (0 ≤ λ ≤ 2) in the weak-coupling regime. In the case of anisotropic antiferromagnetic exchange (J > 0) and on-site repulsion (U > 0), the ground state is characterized by the spin-density-wave (SDW) and bond-charge-density-wave (BCDW) insulating phases. We identify the SDW correlation corresponding to the transverse SDW± phases with a gapless spin excitation (Δs=0) for λ < 4/3 and to the longitudinal SDWz phase with a spin gap (Δs > 0) for λ > 4/3, respectively. The charge excitation is always gapped (Δc > 0) in the whole regime, and the BCDW and SDWz phases show a long-range order. We also examine effects of the nonlocal Umklapp scattering of parallel-spin electrons, which play a role to weaken the BCDW phase and to enhance the SDW phase slightly. The results demonstrate that the properties of our model are not identical with those of the conventional t–U–J model.

THE DYNAMICS OF GEOMETRIC DISCORD AND ITS TRANSFER IN ATOM-CAVITY-RESERVOIR SYSTEM

2013 ◽  
Vol 27 (24) ◽  
pp. 1350136 ◽  
Author(s):  
TAO WU ◽  
XUE-KE SONG ◽  
LIU YE
Keyword(s):  
Strong Coupling ◽  
Weak Coupling ◽  
Quantum Discord ◽  
Dissipative System ◽  
Strong Coupling Regime ◽  
Weak Coupling Regime ◽  
Geometric Quantum Discord ◽  
Reservoir System

The dynamics of geometric discord (GD) and its transfer in a dissipative system consisting of two independent atom-cavity-reservoir subsystems under the strong coupling and the weak coupling regimes is studied. It is shown that the GD of the atoms and the cavities oscillatorily decays to zero while the reservoirs begin to present nonzero geometric quantum discord already immediately after t = 0 in the strong coupling regime. However, in the weak coupling regime, the GD between the atoms progressively decays becoming zero and the discord between the reservoirs arises from zero to a steady value, while the cavities remain almost uncorrelated during the evolution. We also show that the amount of GD contained in atoms and reservoirs depends on the purity p and it is proportional to p, the smaller the value of p the smaller the amount of GD. It is worth noting that, in both strong coupling and the weak coupling regimes, the results show that GD initially stored in the atoms will eventually be completely transferred to the reservoirs, independent of the parameters, but the transfer is mediated via the cavities in the strong coupling regime, while it is almost directly in the weak coupling regime.

SPIN GAPLESS BOND-ORDERED PHASE IN THE EXTENDED HUBBARD CHAIN WITH SPIN-DEPENDENT REPULSION

2011 ◽  
Vol 25 (27) ◽  
pp. 3555-3568 ◽  
Author(s):  
HANQIN DING ◽  
JUN ZHANG
Keyword(s):  
Phase Diagram ◽  
Renormalization Group ◽  
Weak Coupling ◽  
Nearest Neighbor ◽  
Density Wave ◽  
Spin Density Wave ◽  
Extended Hubbard Model ◽  
Weak Coupling Regime ◽  
One Dimensional ◽  
Plane Anisotropy

Using the field theoretical bosonization and renormalization group techniques, we analytically study quantum phase diagram of a one-dimensional half-filled extended Hubbard model with on-site (U) and spin-dependent nearest-neighbor interactions (V⊥, V‖) in the weak coupling regime. In the case of easy-plane anisotropy (V⊥ > V‖) and at V‖ < U/2, the existence of bond-ordered spin-density-wave phase, corresponding to spin gapless transverse magnetization located on bonds (BSDW±) is shown.

scholarly journals One-dimensional microcavity-based optical parametric oscillator: Generation of balanced twin beams in strong and weak coupling regime

2011 ◽  
Vol 83 (20) ◽  
Author(s):  
Marco Abbarchi ◽  
Vincenzo Ardizzone ◽  
Timothée Lecomte ◽  
Aristide Lemaître ◽  
Isabelle Sagnes ◽  
...  
Keyword(s):  
Optical Parametric Oscillator ◽  
Weak Coupling ◽  
Parametric Oscillator ◽  
Weak Coupling Regime ◽  
One Dimensional ◽  
Optical Parametric

scholarly journals Monitoring of Nonadiabatic Effects in Individual Chromophores by Femtosecond Double-Pump Single-Molecule Spectroscopy: A Model Study

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 231
Author(s):  
Maxim Gelin ◽  
Elisa Palacino-González ◽  
Lipeng Chen ◽  
Wolfgang Domcke
Keyword(s):  
Population Dynamics ◽  
Density Matrix ◽  
Strong Coupling ◽  
Single Molecule ◽  
Weak Coupling ◽  
Electronic States ◽  
Strong Coupling Regime ◽  
Weak Coupling Regime ◽  
Electronic Density ◽  
Optical Gap

We explore, by theoretical modeling and computer simulations, how nonadiabatic couplings of excited electronic states of a polyatomic chromophore manifest themselves in single-molecule signals on femtosecond timescales. The chromophore is modeled as a system with three electronic states (the ground state and two non-adiabatically coupled excited states) and a Condon-active vibrational mode which, in turn, is coupled to a harmonic oscillator heat bath. For this system, we simulate double-pump single-molecule signals with fluorescence detection for different system-field interaction strengths, from the weak-coupling regime to the strong-coupling regime. While the signals are determined by the coherence of the electronic density matrix in the weak-coupling regime, they are determined by the populations of the electronic density matrix in the strong-coupling regime. As a consequence, the signals in the strong coupling regime allow the monitoring of nonadiabatic electronic population dynamics and are robust with respect to temporal inhomogeneity of the optical gap, while signals in the weak-coupling regime are sensitive to fluctuations of the optical gap and do not contain information on the electronic population dynamics.

PHASE DIAGRAM OF ONE-DIMENSIONAL DEFORMED t–J1–J2 MODEL WITH FRUSTRATED EXCHANGE INTERACTION

2011 ◽  
Vol 25 (17) ◽  
pp. 1441-1455 ◽  
Author(s):  
HANQIN DING ◽  
JUN ZHANG
Keyword(s):  
Phase Diagram ◽  
Exchange Interaction ◽  
Charge Density Wave ◽  
Weak Coupling ◽  
Density Wave ◽  
Spin Density Wave ◽  
Weak Coupling Regime ◽  
One Dimensional ◽  
The One ◽  
Bond Charge

In this paper, we study the phase diagram of the one-dimensional deformed t–J1–J2 model with frustrated exchange interaction. The introduction of the deformed parameter ζ softens the strength of the induced four- and six-electron interactions caused by the no-double occupancy constraint. For the small ζ and in the weak-coupling regime, we use the bosonization approach and the renormalization group techniques to obtain the phase diagram, which is characterized by the singlet-(SS) and triplet-superconducting (TS), spin-density-wave (SDW) as well as bond-charge-density wave (BCDW) instabilities. The TS and BCDW phases are realized in the whole regime while the SDW and SS correlations depend on J2/J1 < (J2/J1)c or J2/J1 > (J2/J1)c, where (J2/J1)c = 1/3. Furthermore, the deformed model with ζ ≪ 1 is expected to adiabatically connect to the conventional t–J1–J2 model with ζ = 1.

Crossover from the strong-coupling to the weak-coupling regime in the SU(2)-symmetric Thirring model

1983 ◽  
Vol 94 (6-7) ◽  
pp. 254-258 ◽  
Author(s):  
G.I. Japaridze ◽  
A.A. Nersesyan ◽  
P.B. Wiegmann
Keyword(s):  
Strong Coupling ◽  
Weak Coupling ◽  
Thirring Model ◽  
Weak Coupling Regime

scholarly journals Bound states in the continuum in strong-coupling and weak-coupling regimes under the cylinder – ring transition

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nikolay Solodovchenko ◽  
Kirill Samusev ◽  
Daria Bochek ◽  
Mikhail Limonov
Keyword(s):  
Strong Coupling ◽  
Weak Coupling ◽  
Bound States ◽  
Dielectric Cylinder ◽  
Weak Coupling Regime ◽  
Field Zone ◽  
The Past ◽  
Resonant Modes ◽  
Avoided Crossing ◽  
The Continuum

Abstract Bound states in the continuum (BIC) have been at the forefront of research in optics and photonics over the past decade. It is of great interest to study the effects associated with quasi-BICs in the simplest structures, where quasi-BICs are very pronounced. An example is a dielectric cylinder, and in a number of works, quasi-BICs have been studied both in single cylinders and in structures composed of cylinders. In this work, we studied the properties of quasi-BICs during the transition from a homogeneous dielectric cylinder in an air environment to a ring with narrow walls while increasing the diameter of the inner air cylinder gradually. The results demonstrate the quasi-BIC crossover from the strong-coupling to the weak-coupling regime, which manifests itself in the transition from the avoided crossing of branches to their intersection with the quasi-BIC being preserved on only one straight branch. In the regime of strong-coupling and quasi-BIC, three waves interfere in the far-field zone: two waves corresponding to the resonant modes of the structure and the wave scattered by the structure as a whole. The validity of the Fano resonance concept is discussed since it describes the interference of only two waves under weak coupling conditions.

Sign in / Sign up

Export Citation Format

Share Document