Related papers: The Gap Function Phi(k,w) for a Two-leg t-J Ladder…
The $\phi$-$\Lambda(1520)$ interference effect in the $\gamma p\to K^+K^-p$ reaction has been measured for the first time in the energy range from 1.673 to 2.173 GeV. The relative phases between $\phi$ and $\Lambda(1520)$ production…
Using mainly numerical methods, we investigate the width of the spin gap of a spin-1/2 two-leg ladder described by $\cH= J_\rl \sum_{j=1}^{N/2} [ \vS_{j,a} \cdot \vS_{j+1,a} + \vS_{j,b} \cdot \vS_{j+1,b} ] + J_\rr \sum_{j=1}^{N/2} [\lambda…
We review results of an analysis of pipi interactions in S, P and D waves for two-pion effective mass from threshold to about 1.4 GeV. In particular we show a recent improvement of this analysis above the K anti-K threshold using more data…
We have numerically investigated the doped t-J ladder using exact diagonalization. We have studied both the limit of strong inter-chain coupling and isotropic coupling. The ladder scales to the Luther-Emery liquid regime in the strong…
We investigate the ground state properties of spinless fermions on a two leg ladder, by allowing the nearest-neighbour hopping dimerization in one leg and uniform hopping in the other. In the non-interacting limit, we find that, at…
We study the frequency dependencies of the fermion and photon dressing functions in dynamical gap generation in graphene. We use a low energy effective QED-like description, but within this approximation, we include all frequency dependent…
The nature of pseudogap lies at the heart of strongly-interacting superconductivity and superfluidity. With known pairing interactions, unitary Fermi gases provide an ideal testbed to verify whether a pseudogap can arise from many-body…
An effective residual interaction for a meson-meson system is computed in lattice QCD. We describe the theoretical framework and present its application to the I=2 channel S-wave interaction of the pi pi system. Scattering phase shifts are…
We study a superconducting hetro-junction with one side characterized by the unconventional chiral $p$-wave gap function $p_x\pm ip_y$ and the other side the conventional $s$-wave one. Though a relative phase of $\pm \frac{\pi}{2}$ between…
An S=1/2 anti-ferromagnetic spin chain is mapped to the two-flavor massless Schwinger model, which admits a gapless mode. In a spin ladder system rung interactions break the chiral invariance. These systems are solved by bosonization. If…
The dispersions, weights, and widths of the peaks of the single-particle spectral function in the presence of pair correlations, for a Fermi gas with either attractive or repulsive short-range inter-particle interaction, are determined in…
Using density matrix renormalization group calculations, we compare results obtained for the t-J, one-band Hubbard and three-band Hubbard models of a two-leg CuO ladder. Spin and charge gaps, pair binding energies, and effective pair…
We consider asymmetric spin-1/2 two-leg ladders with non-equal antiferromagnetic (AF) couplings J_|| and \kappa J_|| along legs (\kappa <= 1) and ferromagnetic rung coupling, J_\perp. This model is characterized by a gap \Delta in the…
The femtoscopic correlation function has been established in recent years as a high-precision tool for investigating hadron-hadron interactions and exotic states, providing stringent constraints on the dynamics of low-energy strong…
We study the Josephson diode effect realized purely by geometry in a Kitaev-ladder Josephson junction composed of two parallel spinless $p$-wave chains coupled by an interleg hopping $t_\perp$. The junction is governed by two phases: the…
The Wigner function W(q,p) is formulated as a phase-space path integral, whereby its sign oscillations can be seen to follow from interference between the geometrical phases of the paths. The approach has similarities to the path-centroid…
Considering model Hamiltonians that respect the symmetry properties of the pnictides, it is argued that pairing interactions that couple electrons at different orbitals with an orbital-dependent pairing strength inevitably lead to interband…
I review theoretical ideas and implications of experiments for the gap structure and symmetry of the Fe-based superconductors. Unlike any other class of unconventional superconductors, one has in these systems the possibility to tune the…
Lieb excitations are fundamental to the understanding of the low energy behaviour of many-body quantum gases. Here we study the spectral function of a Tonks-Girardeau gas in a finite sized Kronig-Penney potential and show that the Lieb-I…
The structure and stability of dilute degenerate Fermi gases trapped in an external potential is discussed with special emphasis on the influence of s- and p-wave interactions. In a first step an Effective Contact Interaction for all…