Circulating persistent current and induced magnetic field in a fractal network

Abstract

We present the overall conductance as well as the circulating currents in individual loops of a Sierpinski gasket (SPG) as we apply bias voltage via the side attached electrodes. SPG being a self-similar structure, its manifestation on loop currents and magnetic fields are examined in various generations of this fractal and it has been observed that for a given configuration of the electrodes, the physical quantities exhibit certain regularity as we go from one generation to another. Also a notable feature is the introduction of anisotropy in hopping causes an increase in magnitude of overall transport current. These features are a subject of interest in this article.

Current vortices in hexagonal graphene quantum dots

“…Such current vortices can be used in the design of quantum devices 30 , since their currents give rise to a extremely concentrated magnetic field. These currents can also be used to generate spin based quantum devices, since the orientation of a spin placed at the center of the vortex can be manipulated by the induced magnetic field 31 . Conversely, the current vortex will be affected by external magnetic perturbations in its proximity.…”

Modulation of circular current and associated magnetic field in a molecular junction: A new approach

“…where . With these bond currents the net circular current is calculated from the relation 24 25 39 40 41 …”

“…Due to this circular current a net magnetic field is established. The local magnetic field at any arbitrary point r (say) inside the molecule can be determined using the Biot-Savart’s law 24 25 39 40 41 …”

“…In other work Lidar and Thywissen have established38 that a localized magnetic field, which may reach up to 10 mT, can be generated with the help of an infinite array of parallel current carrying wires, though it has severe limitation due to heating effect and one has to work at much lower temperature (<2.4 mK). Comparing all these propositions we can argue that bias induced magnetic field, associated with circular current, in a nano-junction is quite robust and easy to operate2425394041. The essential motivations behind the consideration of a molecular junction with loop structure(s) are as follows: (a) Bias induced circular current produces strong magnetic field (that can also be varied in a wide range) at the molecular/nano-scale level compared to the net junction current.…”

Modulation of circular current and associated magnetic field in a molecular junction: A new approach

“…. With these bond currents the net circular current is calculated from the relation 24,25,[39][40][41]…”