Related papers: Quasiparticles as composite objects in the RVB sup…
Taking into account microscopic properties of most usual high-$T_{c}$ superconductors, like cuprates, we define a class of microscopic model Hamiltonians for two fermions (electrons or holes) and one boson (bipolaron) on the two-dimensional…
Excitons and their complexes govern optical-related behaviors in semiconductors. Here, using angle-resolved photoemission spectroscopy (ARPES), we have elucidated the light-matter interaction mediated by quasi-steady excitonic complexes…
We study a simple electron-phonon model on square and triangular versions of the Lieb-lattice using an asymptotically exact strong coupling analysis. At zero temperature and electron density $n = 1$ (one electron per unit cell), for various…
Many theoretical approaches find d-wave superconductivity in the prototypical one-band Hubbard model for high-temperature superconductors. At strong-coupling (U > W, where U is the on-site repulsion and W=8t the bandwidth) pairing is…
Assemblies of interacting quantum particles often surprise us with properties that are difficult to predict. One of the simplest quantum many-body systems is the spin 1/2 Heisenberg antiferromagnetic chain, a linear array of interacting…
We discuss the type of pairing in the hexagonal pnictide superconductor SrPtAs, taking into account its multiband structure. The topological chiral $d$-wave state with time-reversal-symmetry breaking has been anticipated from the…
Confinement is a process by which particles with fractional quantum numbers bind together to form quasiparticles with integer quantum numbers. The constituent particles are confined by an attractive interaction whose strength increases with…
On the basis of the Bogolubov-de Gennes theory we develop an analytical description of low-energy extended quasiparticle states around an isolated flux line in a superconductor with gap nodes. The wavefunctions of these excitations and the…
We investigate a spin-full double quantum dot (DQD) coupled to the leads in a pseudospin valve configuration. The interplay of interaction and interference produces in the stability diagram a rich variety of resonances, modulated by the…
A major puzzle about the nature of the iron-based superconductivity appears in the case of the alkaline iron selenides. Compared to the iron pnictides, these systems have only electron Fermi pockets (i.e. no hole Fermi pockets) but…
We study impurity scattering in the normal and d-wave superconducting states of line nodal semimetals and show that, due to additional scattering phase space available for impurities on the surface, the quasiparticle interference pattern…
We investigate the impact of s-wave spin-singlet pairing on antiferromagnetic semimetals with Dirac points or nodal loops at the Fermi level. The electron pairing is generally shown to convert the semimetal into a tunable nodal…
Valence bond (VB) states as the formation mechanism of Cooper pairs, eventually leading to high-temperature superconductivity, remain a controversial topic. Although various VB-like states find variational relevance in the description of…
The origin of the spin resonance observed in CeCoIn5 with Inelastic Neutron Scattering is subject to debate. It has been shown recently that in this heavy electron compound at low temperature an instability to a ground state with coexisting…
We present a numerical study of competing orders in the 1D $t$-$J$ model with long-range RKKY-like staggered spin interactions. By circumventing the constraints imposed by Mermin-Wagner's theorem, this Hamiltonian can realize long-range…
In this work, we present numerical results which support SO(5) symmetry as a concept unifying superconductivity and antiferromagnetism in the high-temperature superconductors. Using exact cluster diagonalization, we verify the recently…
Recent Scanning Tunneling Microscope (STM) experiments offer a unique insight into the inner workings of the superconducting state of high-Tc superconductors. Deliberately placed inside the material impurities perturb the coherent state and…
We study a hybrid quantum system consisting of spin ensembles and superconducting flux qubits, where each spin ensemble is realized using the nitrogen-vacancy centers in a diamond crystal and the nearest-neighbor spin ensembles are…
We consider a general problem of a Josephson contact between two multiband superconductors with coexisting superconducting and magnetic phases. As a particular example, we use the quasiclassical theory of superconductivity to study the…
The energy, momentum and temperature dependence of the quasiparticle local density of states (LDOS) of a two-dimensional $d_{x^2-y^2}$-wave superconductor with random disorder is investigated using the first-order T-matrix approximation.…