arXiv subjects

L. Privitera

Publications and source records attributed to L. Privitera.

4 recordsLinked to original sources

arXiv2022

Tunable interface states between Floquet-Weyl semimetals

Weyl semimetals and nodal line semimetals are characterized by linear electronic bands touching at zero-dimensional points and one-dimensional lines, respectively. Recently, it has been predicted that nodal line semimetals can be driven into tunable Floquet-Weyl semimetals by circularly polarized light. Here, we study the occurrence of interface states between two regions of a nodal line semimetal shined by two beams of light with opposite circular polarizations. Within a minimal model, we find remarkable modifications of the energy structure by tuning the polarized light, such as the possible generation of van Hove singularities. Moreover, by adding a $\delta$-doping of magnetic impurities along the interfacial plane, we show the occurrence of a switchable and topologically non-trivial, vortex-like pseudo-spin pattern of the interface states.

cond-mat.mes-hall↗

arXiv2019

Transport signatures of a Floquet topological transition at the helical edge

The manipulation of the helical edge states of two-dimensional topological insulators is crucial for the development of technological applications. Recently, an important step forward, namely, the experimental realization of a quantum point contact between helical edges, has been accomplished. We theoretically predict that such a quantum point contact, in the presence of a time periodic applied electric field, is characterized by a topological quantum phase transition in the Floquet spectrum. Moreover, we show that it is possible to detect this dynamical topological quantum phase transition by a bare conductance measurements.

cond-mat.mes-hall↗

arXiv2019

Feasible model for photo-induced interband pairing

Recently, it has been proposed that a mechanism for the appearance of non-equilibrium superconductivity in a resonantly driven semiconductor with repulsive interband interactions exists.~\cite{Goldstein_PRB15} The underlying microscopic model relies on the appearance of a specific fermionic dissipation mechanism and the careful simultaneous tailoring of the electronic dispersion relation and electron-electron interactions. We, instead, show that the phenomenon is rather general and does not need a special fine tuning of parameters. By considering a pair of bands with locally the same sign of concavity, we demonstrate that interband pairing arises under the natural assumption of the presence of phononic baths and radiative recombination. In light of these findings, we demonstrate how the emergence of superconductivity can be understood in terms of standard equilibrium interband BCS theory.

cond-mat.mes-hall↗

arXiv2017

Edge states reconstruction from strong correlations in quantum spin Hall insulators

We study quantum spin Hall insulators with local Coulomb interactions in the presence of boundaries using dynamical mean field theory. We investigate the different influence of the Coulomb interaction on the bulk and the edge states. Interestingly, we discover an edge reconstruction driven by electronic correlations. The reason is that the helical edge states experience Mott localization for an interaction strength smaller than the bulk one. We argue that the significance of this edge reconstruction can be understood by topological properties of the system characterized by a local Chern marker.

cond-mat.str-el↗