249 research outputs found
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.Comment: 10 pages, 16 figures (Accepted for Publication in: The European
Physical Journal B-Condensed Matter and Complex Systems
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.Comment: 6 pages, 5 figures (Accepted for Publication in Europhysics Letters
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