Related papers: Strong Coupling Expansion for the Pairing Hamilton…
Describing and achieving `unconventional' superconductivity remains a forefront challenge in quantum many-body physics. Here we use a unitary mapping, combined with the well-established properties of the attractive Hubbard model to…
The electromagnetic response of the CuO2-planes is calculated within a strong coupling theory using model tight binding bands and momentum dependent pairing interactions representing spin fluctuations and phonon exchange. The…
We extend the microscopic particle-rotor model for hypernuclear low-lying states by including the derivative and tensor coupling terms in the point-coupling nucleon-$\Lambda$ particle ($N\Lambda$) interaction. Taking $^{13}_{~\Lambda}$C as…
A self-consistent set of equations for the one-electron self-energy in the ladder approximation is derived for the attractive Hubbard model in the superconducting state. The equations provide an extension of a T-matrix formalism recently…
An investigation of the weak coupling region of 2D SU(N) spin models is presented. An expansion of the free energy and correlation functions at low temperatures is performed in the link formulation with periodic boundary conditions (BC).…
Experimental platforms based on trapped ions, cold molecules, and Rydberg atoms have made possible the investigation of highly-nonlocal spin-${1/2}$ Hamiltonians with long-range couplings. Here, we study the effects of such non-local…
We study weak-coupling perturbation expansions for the ground-state energy of the Hamiltonian with the generalized spiked harmonic oscillator potential V(x) = Bx^2 + A/x^2 + lambda/x^alpha, and also for the bottoms of the angular momentum…
Strong coupling is a phenomenon which occurs when the interaction between two resonance systems is so strong that the oscillatory energy exchange between them exceeds all dissipative loss channels. Each resonance can then no longer be…
We study the capacitance-coupled Josephson junction array beyond the small-coupling limit. We find that, when the scale of the system is large, its Hamiltonian can be obtained without the small-coupling approximation and the system can be…
We use recently developed strong-coupling expansion methods to study the two-particle spectra for the frustrated alternating Heisenberg model, consisting of an alternating nearest neighbor antiferromagnetic exchange and a uniform second…
In this paper we discuss effective strong coupling constants. Those are well behaved in the low-Q^2 domain, contrarily to alpha_s from pQCD. We present an extraction of an effective strong coupling constant from Jefferson Lab polarized data…
We study the strong coupling behaviour of fixed length single trace operators in the scalar SU(2) sector of ${\cal N} = 4$ SYM. We assume the recently proposed connection with a twisted half-filled Hubbard model. By explicit direct…
Superconductivity in the Hubbard model on a square lattice near half filling is studied using an optimization (or correlated) variational Monte Carlo method. Second-order processes of the strong-coupling expansion are considered in the wave…
High-$T_c$ superconductors are usually described as strongly correlated electronic systems. This feature deeply affects the one-particle and two-particle properties of the system. In particular, a large incoherent background developes on…
A continuous sequence of infinitesimal unitary transformations is used to diagonalize the quantum sine-Gordon model for \beta^2\in(2\pi,\infty). This approach can be understood as an extension of perturbative scaling theory since it links…
The status of coupling constant unification in the standard model and its supersymmetric extension are discussed. Uncertainties associated with the input coupling constants, $m_{t}$, threshold corrections at the low and high scales, and…
The ground state and the excitation spectrum of strongly correlated electrons in quantum dots are investigated. An analytical solution is constructed by exact diagonalization of the Hamiltonian in terms of the $N$-particle eigenmodes.
A continuous sequence of infinitesimal unitary transformations, combined with an operator product expansion for vertex operators, is used to diagonalize the quantum sine-Gordon model for 2 pi < beta^2 < infinity. The leading order of this…
An optical nanoantenna and adjacent atomic systems are strongly coupled when an excitation is repeatedly exchanged between these subsystems prior to its eventual dissipation into the environment. It remains challenging to reach the strong…
Pentagon Operator Product Expansion provides a non-perturbative framework for analysis of scattering amplitudes in planar maximally supersymmetric gauge theory building up on their duality to null polygonal super Wilson loop and…