Related papers: Strong Coupling Approach to the Supersymmetric Kon…
We present an analytic universal impurity solver for strongly correlated electrons. We extend the many-body perturbation expansion via suitable two-particle renormalizations from the Fermi-liquid regime to the critical region of the…
In a previous work (N. H. Tong, Phys. Rev. B 92, 165126 (2015)), an equation-of-motion based series expansion formalism was used to do the second-order strong-coupling expansion for the single-particle Green function of the Anderson…
Strong - weak coupling duality in string theory allows us to compute physical quantities both at the weak coupling end and at the strong coupling end. Furthermore perturbative string theory can be used to compute corrections to the leading…
We adapt strong-coupling methods first used in the one-channel Kondo model to develop a simple description of the spin-$1\over 2$ two-channel Kondo model with channel anisotropy. Our method exploits spin-charge decoupling to develop a…
The Kondo lattice model describes a quantum phase transition between the antiferromagnetic state and heavy-fermion states. Applying the dual-fermion approach, we explore possible superconductivities emerging due to the critical…
In a $\mathcal{N}=2$ superconformal gauge theory with matter hypermultiplets transforming in the symmetric and anti-symmetric representations of SU($N$), we study the integrated correlators of two Coulomb-branch operators and two moment-map…
We study higher-spin ($S \geq 1$) generalization of the one-dimensional Kondo-Heisenberg model, in which the local spin-$S$ moments of the Kondo lattice model interact with each other via the antiferromagnetic Heisenberg interaction…
Two dimensional large-N chiral models on the square and honeycomb lattices are investigated by a strong coupling analysis. Strong coupling expansion turns out to be predictive for the evaluation of continuum physical quantities, to the…
The periodic Anderson impurity model on the Lieb lattice is studied by the slave-boson mean-field approximation in the strong interaction limit. The electron structure of conduction electrons on the Lieb lattice features both the band…
Correlators of gauge invariant operators provide useful information on the dynamics, phases and spectra of a quantum field theory. In this paper, we consider N=1 supersymmetric theories and focus our attention on the supercurrent multiplet.…
We analyze the ground state properties of the two-dimensional quantum antiferromagnet with a S=1/2 Kondo impurity. Perturbation theory around the strong Kondo coupling limit is developed and the results compared with studies, based on exact…
We study the 3-point functions of gauge-invariant scalar operators in four dimensional $\mathcal{N}=2$ superconformal quiver theories using supersymmetric localization in the planar limit of a large number of colors. By exploiting a web of…
We study strong coupling phenomena in U(1) gauge theory on the non-commutative plane. To do so, we make use of a T-dual description in terms of an $N\to\infty$ limit of U(N) gauge theory on a commutative torus. The magnetic flux on this…
In a certain strong coupling limit, compactification of the $E_8\times E_8$ heterotic string on a Calabi-Yau manifold $X$ can be described by an eleven-dimensional theory compactified on $X\times \S^1/\Z_2$. In this limit, the usual…
We study a class of extremal transitions between topological distinct Calabi--Yau manifolds which have an interpretation in terms of the special massless states of a type II string compactification. In those cases where a dual heterotic…
We study a class of four-dimensional $\mathcal{N}=2$ SU($N$) gauge theories with two massless hypermultiplets in the rank-two antisymmetric representation and $0\leq N_f\leq 4$ fundamental flavors. These theories are superconformal for…
The N=2* theory (mass deformation of N=4 Super-Yang-Mills) undergoes an infinite number of quantum phase transitions in the large-N limit. The phase structure and critical behavior can be analyzed with the help of supersymmetric…
We consider a Kondo impurity coupled to a fermionic host with a power-law density of states near the Fermi level, rho(epsilon) ~ |epsilon|^r, with exponent r<0. Using both perturbative renormalization group (poor man's scaling) and…
Quantum spin impurities coupled to superconductors are under intense investigation for their relevance to fundamental research as well as the prospects to engineer novel quantum phases of matter. Here we develop a large-$N$ mean-field…
We consider a model describing a system where the superconductivity competes with the overscreened Kondo effect. The model consists of a single spin$-\frac{1}{2}$ quantum impurity at the edge of a quantum wire where spin$-1$ bulk fermions…