X. Leyronas

Coupling between planes and chains in YBa2Cu3O7: A possible solution for the order parameter controversy.

We propose to explain the contradictory experimental evidence about the symmetry of the order parameter in

Particle distribution tail and related energy formula

YBa_{2}Cu_{3}O_{7}

Analytical theory of the dressed bound state in highly polarized Fermi gases

by taking into account the coupling between planes and chains. This leads to an anticrossing of the plane and chain band. We include an attractive pairing interaction within the planes and a repulsive one between planes and chains, leading to opposite signs for the order parameter on planes and chains, and to nodes of the gap because of the anticrossing. Our model blends s-wave and d-wave features, and provides a natural explanation for all the contradictory experiments

Theory of nonequilibrium transport in the SU ( N ) Kondo regime

We present a simple derivation of the energy formula found by Tan, relative to the single-channel Hamiltonian relevant for ultracold Fermi gases. This derivation is generalized to particles with different masses, to arbitrary mixtures, and to two-dimensional space. We show how in a field-theoretic approach, the 1/k{sup 4} tail in the momentum distribution and the energy formula arise in a natural way. As a specific example, we consider quantitative calculations of the energy from different formulas within the ladder diagram approximation in the normal state. The comparison of the results provides an indication on the quality of the approximation.

Current noise through a Kondo quantum dot in a SU(N) Fermi liquid state.

We present an analytical treatment of a single ↓-atom within a Fermi sea of ↑-atoms, when the interaction is strong enough to produce a bound state, dressed by the Fermi sea. Our method makes use of a diagrammatic analysis, with the involved diagrams taking only into account at most two particle-hole pairs excitations. The agreement with existing Monte Carlo results is excellent. In the BEC limit our equation reduces exactly to the Skorniakov and Ter-Martirosian equation. We present results for ↑- and ↓-atoms with different masses, which is of interest for experiments in progress.

Bound states of three and four resonantly interacting particles

Using a Fermi-liquid approach, we provide a comprehensive treatment of the current and current noise through a quantum dot whose low-energy behavior corresponds to an

Quantum wells, wires and dots with finite barrier: analytical expressions for the bound states

\text{SU}(N)

Superfluid equation of state of dilute composite bosons

Kondo model, focusing on the case

Non-Cayley-tree model for quasiparticle decay in a quantum dot

N=4

Plane-chain coupling in YBa2Cu3O7: Impurity effect on the critical temperature.

relevant to carbon nanotube dots. We show that for general