Superexchange Driven Singlet-Triplet Transition in Quantum Dots Array Embedded in Kagome Lattice System

Abstract

The envisaged revolutionary impact of the quantum computer has continued to elucidate diverse means to design and build physical quantum computers. In condensed matter physics, one of the means is to design materials to host two-electron quantum dots (QDs) which can be manipulated into singlet-triplet (S-T) transition. This transition which is read as the quantum bits (qubits) that is considered as a possible logic gate for the quantum computers is enhanced by external magnetic field which is a potential source of decohenrence. In the study here therefore, the possibility of using a superexchange induced internal magnetic field to drive the S-T transition in QDs embedded in a kagome lattice system (KLS) is examined. The design is by embedding the two-electron QDs into the frustrated sites of the KLS and then filling the other sites with single electrons. The parameter space of this KLS to achieve the S-T in the QDs array are obtained from the superexchange interaction in correlated  variational  study of the system.

Keywords: frustrated system,  kagome  lattice, quantum dot, singlet-triplet transition, quantum computer