arXiv subjects

Moumita Patra

Publications and source records attributed to Moumita Patra.

23 records · Page 2Linked to original sources

arXiv2018

Simultaneous spin-based Boolean logic operations with re-programmable functionality

Construction of parallel logic gates at nano-scale level undoubtedly improves the efficiency of computable operations. In this work we put forward a new idea of designing two distinct logical operations {\em simultaneously} in the two output leads of a three-terminal bridge setup which on one hand is highly stable as all the results are valid for a wide range of parameter values and on the other hand easy to engineer. Our system can be reprogrammed to have all the two-input logic gates with two operations at a time by selectively choosing the physical parameters describing the system, viz, Rashba spin-orbit (SO) interaction, magnetic flux, and Fermi energy. Finally, we explore the possible storage mechanism as well using our model.

cond-mat.mes-hall↗

arXiv2017

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

A new proposal is given to control local magnetic field in a molecular junction. In presence of finite bias a net circular current is established in the molecular ring which induces a magnetic field at its centre. Allowing a direct coupling between two electrodes, due to their close proximity, and changing its strength we can regulate circular current as well as magnetic field for a wide range, without disturbing any other physical parameters. We strongly believe that our proposal is quite robust compared to existing approaches of controlling local magnetic field and can be verified experimentally.

cond-mat.mes-hall↗

arXiv2016

Characteristics of persistent spin current components in a quasi-periodic Fibonacci ring with spin-orbit interactions: Prediction of spin-orbit coupling and on-site energy

In the present work we investigate the behavior of all three components of persistent spin current in a quasi-periodic Fibonacci ring subjected to Rashba and Dresselhaus spin-orbit interactions. Analogous to persistent charge current in a conducting ring where electrons gain a Berry phase in presence of magnetic flux, spin Berry phase is associated during the motion of electrons in presence of a spin-orbit field which is responsible for the generation of spin current. The interplay between two spin-orbit fields along with quasi-periodic Fibonacci sequence on persistent spin current is described elaborately, and from our analysis, we can estimate the strength of any one of two spin-orbit couplings together with on-site energy, provided the other is known.

cond-mat.mes-hall↗

arXiv2016

Unconventional low-field magnetic response of a diffusive ring with spin-orbit coupling

We report an unconventional behavior of electron transport in the limit of zero magnetic flux in a one-dimensional disordered ring, be it completely random or any correlated one, subjected to Rashba spin-orbit (SO) coupling. It exhibits much higher circulating current compared to a fully perfect ring for a wide range of SO coupling yielding larger electrical conductivity which is clearly verified from our Drude weight analysis.

cond-mat.mes-hall↗

arXiv2016

Anomalous magnetic response of a quasi-periodic mesoscopic ring in presence of Rashba and Dresselhaus spin-orbit interactions

We investigate the properties of persistent charge current driven by magnetic flux in a quasi-periodic mesoscopic Fibonacci ring with Rashba and Dresselhaus spin-orbit interactions. Within a tight-binding framework we work out individual state currents together with net current based on second-quantized approach. A significant enhancement of current is observed in presence of spin-orbit coupling and sometimes it becomes orders of magnitude higher compared to the spin-orbit interaction free Fibonacci ring. We also establish a scaling relation of persistent current with ring size, associated with the Fibonacci generation, from which one can directly estimate current for any arbitrary flux, even in presence of spin-orbit interaction, without doing numerical simulation. The present analysis indeed gives a unique opportunity of determining persistent current and has not been discussed so far.

cond-mat.mes-hall↗