Search results for "Insula"

Topological Hamiltonian as an exact tool for topological invariants

2012

We propose the concept of `topological Hamiltonian' for topological insulators and superconductors in interacting systems. The eigenvalues of topological Hamiltonian are significantly different from the physical energy spectra, but we show that topological Hamiltonian contains the information of gapless surface states, therefore it is an exact tool for topological invariants.

Spin current pumping in helical Luttinger liquids

2013

We study the DC spin current induced into an unbiased quantum spin Hall system through a two-point contacts setup with time dependent electron tunneling amplitudes. By means of two external gates, it is possible to drive a current with spin-preserving and spin-flipping contributions showing peculiar oscillations as a function of pumping frequency, electron-electron interaction and temperature. From its interference patterns as a function of the Fabry-Perot and Aharonov-Bohm phases, it is possible to extract information about the helical nature of the edge states and the intensity of the electron-electron interaction.

Introduction to Spintronics

2015

Spintronics was born in 1988 with the discovery of GMR provided simultaneously by A. Fert and P. Grunberg and rewarded in 2007 with the Nobel Prize in Physics. This field has since been largely exploited on the market, for example it has been at the base of every hard disk read head. Spintronics field is extremely active and interesting from both a fundamental point of view and for technological applications. Currently, with the aim at new functionalities, there is an increased activity from materials research perspective to understand and develop spintronics devices using materials with new properties like carbon nanotubes, graphene, topological insulators and molecules. This chapter will …

Topological protection of highly entangled non-Gaussian two-photon states

2021

Abstract We study theoretically the evolution of entangled non-Gaussian two-photon states in disordered topological lattices. Specifically, we consider spatially entangled two-photon states, modulated by Laguerre polynomials up to the 3rd order, which feature ring-shaped spatial and spectral correlation patterns. Such states are discrete analogs of photon-subtracted squeezed states, which are ubiquitous in optical quantum information processing or sensing applications. We find that, in general, a higher degree of entanglement coincides with a loss of topological protection against disorder, this is in line with previous results for Gaussian two-photon states. However, we identify a particul…

Exploring Interacting Topological Insulators with Ultracold Atoms: The Synthetic Creutz-Hubbard Model

2016

25 pags., 13 figs. -- Open Access funded by Creative Commons Atribution Licence 4.0

Interface states in polariton topological insulators

2019

We address linear and nonlinear topological interface states in polariton condensates excited at the interface of the honeycomb and Lieb arrays of microcavity pillars in the presence of spin-orbit coupling and Zeeman splitting in the external magnetic field. Such interface states appear only in total energy gaps of the composite structure when parameters of the honeycomb and Lieb arrays are selected such that some topological gaps in the spectrum of one of the arrays overlap with topological or nontopological gaps in the spectrum of the other array. This is in contrast to conventional edge states at the interface of periodic topological and uniform trivial insulators, whose behavior is dete…

MHD evolution of a fragment of a CME core in the outer solar corona

2007

Detailed hydrodynamic modeling explained several features of a fragment of the core of a Coronal Mass Ejection observed with SoHO/UVCS at 1.7 Ro on 12 December 1997, but some questions remained unsolved. We investigate the role of the magnetic fields in the thermal insulation and the expansion of an ejected fragment (cloud) traveling upwards in the outer corona. We perform MHD simulations including the effects of thermal conduction and radiative losses of a dense spherical or cylindrical cloud launched upwards in the outer corona, with various assumptions on the strength and topology of the ambient magnetic field; we also consider the case of a cylindrical cloud with an internal magnetic fi…

Faceted phospholipid vesicles tailored for the delivery of Santolina insularis essential oil to the skin

2015

The aim of this work was to formulate Santolina insularis essential oil-loaded nanocarriers, namely Penetration Enhancer containing Vesicles (PEVs), evaluate the physico-chemical features and stability, and gain insights into their ability to deliver the oil to the skin.S. insularis essential oil was obtained by steam distillation, and was predominantly composed of terpenes, the most abundant being β-phellandrene (22.6%), myrcene (11.4%) and curcumenes (12.1%). Vesicles were prepared using phosphatidylcholine, and ethylene or propylene glycol were added to the water phase (10% (v/v)) to improve vesicle performances as delivery systems. Vesicles were deeply characterized by light scattering,…

La Terricola (Mammalia, Rodentia) fossile della Sicilia: tassonomia e biogeografia

2008

Osservazioni preliminari sulla tassonomia e la biogeografia di Microtus (Terricola) (Mammalia, Rodentia) fossile della Sicilia

2011

Biogeographia vol. )O(X - 2011 (Pubblicato il 23 dicembre 2011) La Biogeografia del/a Sicilia Osservazioni preliminari sulla tassonomia e la biogeografia di Micmtus (Terricola) (Mammalia, Rodentia) fossile della Sicilia ELISA LOCATELLP‘, FEDERICO MASINl**, DARIA PETRUSO**, BENEDETTO SALA*, GIOVANNI SURDI** * Dzpartimento di Biologzkz ed E2/oluzione, Univerritd degli Studi, 6.50 Ercole I d’Este 32, 44100 Fermm (Italy); e—mzzz'[: eZim.[ocate[[z'@unzfi. it; benedettoyzla @umfe. it *q‘ Dzpzzrtimento di Scienze dellzz Yerm e delMare, Universitzi degli Studi, z1z'czArc/Jimfi 22, 90123 Palermo (Italy) e—mai[: federico. masini @unz]m. it; dzzrizz._petru5o @um;mz. it; gz'0wmnz'.:um&#…