Formation of spin droplet at nu = 5/2 in an asymmetric quantum dot under quantum Hall conditions

摘要

In this work, a quantum dot that is defined asymmetrically by electrostaticmeans induced on a GaAs/AlGaAs heterostructure is investigated to unravel theeffect of geometric constrains on the formation of spin droplets underquantised Hall conditions. The incompressibility of exciting nu = 5/2 state isexplored by solving the Schrodinger equation within spin density functionaltheory, where the confinement potential is obtained self-consistently utilisingthe Thomas-Fermi approximation. Our numerical investigations show that thespatial distribution of the nu = 2 incompressible strips and electronoccupation in the second lowest Landau level considerably differ from theresults of the laterally symmetric quantum dots. Our findings yield twoimportant consequences, first the incompressibility of the intriguing nu = 5/2state is strongly affected by the asymmetry, and second, since theAharonov-Bohm interference patterns depend on the velocity of the particles,asymmetry yields an additional parameter to adjust the oscillation period,which imposes a boundary condition dependency in observing quasi-particlephases.