arXiv subjects

Marek Korkusinski

Publications and source records attributed to Marek Korkusinski.

39 records · Page 3Linked to original sources

arXiv2006

Voltage-controlled coded qubit based on electron spin

We design and analyze a solid state qubit based on electron spin and controlled by electrical means. The coded qubit is composed of a three-electron complex in three tunable gated quantum dots. The two logical states of a qubit, |0L> and |1L>, reside in a degenerate subspace of total spin S=1/2 states. We demonstrate how applying voltages to specific gates changes the one-electron properties of the structure, and show how electron-electron interaction translates these changes into the manipulation of the two lowest energy states of the three-electron complex.

cond-mat.mtrl-sci↗

arXiv2003

Configuration interaction method for Fock-Darwin states

We present a configuration interaction method optimized for Fock-Darwin states of two-dimensional quantum dots with an axially symmetric, parabolic confinement potential subject to a perpendicular magnetic field. The optimization explicitly accounts for geometrical and dynamical symmetries of the Fock-Darwin single-particle states and for many-particle symmetries associated with the center-of-mass motion and with the total spin. This results in a basis set of reduced size and improved accuracy. The numerical results compare well with the quantum Monte Carlo and stochastic variational methods. The method is illustrated by the evolution of a strongly correlated few-electron droplet in a magnetic field in the regime of the fractional quantum Hall effect.

cond-mat.mes-hall↗

arXiv2002

Theory of the spin singlet filling factor $ν=2$ quantum Hall droplet

A theory of electronic properties of a spin-singlet quantum Hall droplet at filling factor $ν=2$ in a parabolic quantum dot is developed. The excitation spectrum and the stability of the droplet due to the transfer of electrons into the second Landau level at low magnetic fields and due to spin flip at the edge at higher magnetic fields is determined using Hartree-Fock, exact diagonalisation, and spin-density functional methods. We show that above a critical number of electrons $N_c$ the unpolarised $ν=2$ quantum Hall droplet ceases to be a ground state in favor of spin-polarised phases. We determine the characteristic pattern in the addition and current-amplitude Coulomb blockade spectra associated with the stable $ν=2$ droplet. We show that the spin transition of the droplet at a critical number of electrons is accompanied by the reversal of the current amplitude modulation at the $ν=2$ line, as observed in recent experiments.

cond-mat.mes-hall↗