Publications: Pre-prints
Nanophysics and Quantum Systems
L. Rossi, F. Dolcini, and F. Rossi Majorana-like localized spin density without bound states in topologically trivial spin-orbit coupled nanowires, ArXiv: 2002.07779
In the topological phase of spin-orbit coupled nanowires Majorana bound states are known to localize at the nanowire edges and to exhibit a spin density orthogonal to both the magnetic field and the spin-orbit field. By investigating a nanowire exposed to a uniform magnetic field with an interface between regions with different spin-orbit couplings, we find that the orthogonal spin density is pinned at the interface even when both interface sides are in the topologically trivial phase, and even when no bound state is present at all. A bound state may additionally appear at the interface, especially if the spin-orbit coupling takes opposite signs across the interface. However, it can be destroyed by a smoothening of the spin-orbit profile or by a magnetic field component parallel to the spin-orbit field. In contrast, the orthogonal spin density persists in various and realistic parameter ranges. We also show that, while the measurement of bulk equilibrium spin currents has been elusive so far, such robust orthogonal spin density peak may provide a way to detect spin current variations across interfaces.
A. Montorsi, S. Fazzzini, and L. Barbiero Homogeneous and domain wall topological Haldane conductors with dressed Rydberg atoms, ArXiv: 1910.11051
The interplay between antiferromagnetic interaction and hole motion is capable of inducing intriguing conducting topological Haldane phases described by a finite non-local string order parameter. Here we show that these states of matter are captured by the one dimensional t−Jz model which can be experimentally realized with dressed Rydberg atoms trapped onto a one dimensional optical lattice. In the sector with vanishing total magnetization exact Bethe ansatz calculations associated to bosonization technique allow to predict that both metallic and superconducting topological Haldane states can be achieved. With the addition of an appropriate magnetic field the system enters in a domain wall structure with finite total magnetization. In this regime conducting topological Haldane states are confined in domains separated by regions where fully polarized Luttinger liquid occurs. A procedure to dynamically stabilize such Haldane topological phases starting from a confined Ising state is also described