Using torsion to manipulate spin currents

Abstract

We address the problem of quantum particles moving on a manifold characterised by the presence of torsion along a preferential axis. In fact, such a torsion may be taylored by the presence of a single screw dislocation, whose Burgers vector measures the torsion amplitude. The problem, first treated in the relativistic limit describing fermions that couple minimally to torsion, is then analysed in the Pauli limit. We show that torsion induces a geometric potential and also that it couples generically to the phase of the wave function, giving rise to the possibility of using torsion to manipulate spin currents in the case of spinor wave functions. These results emerge as an alternative strategy for using screw dislocations in the design of spintronic-based devices.

Topological and non inertial effects on the interband light absorption

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“…That is, for a given disclina-tion, for fixed values of B and Ω, there is an upper limit for the radius of the quantum dot. This is clear if one takes a look at the Hamiltonian (8). If β, as given by Eq.…”

“…Defects, in general, are a nuisance since they impair the electronic properties of the materials. Nevertheless, recent works by some of us [5][6][7][8] have pointed out that topological defects can in fact be used to tailor specific electronic transport properties. Besides the dynamics of carriers, investigations on how topological defects affect the electronic bound states, may also be of importance for the improvement of electronic technology.…”

Introduction to topological defects: from liquid crystals to particle physics

“…Therefore, curvature/torsion can be taken advantage of to taylor the outgoing fluxes for applications in mechanical engineering (acoustics, electronics, thermotronics, optics..., see e.g. [103][104][105][106]). Such perspectives are also under investigations in biology, where the possibility to control the dynamics of defects pairs was shown for tissues prepatterned from photoaligned liquid crystal elastomer [107].…”