Fast optical control of a coded qubit in a triple quantum dot

DIEGO ACOSTA CODEN; SERGIO GOMEZ; RODOLFO ROMERO; OMAR OSENDA; FERRÓN, ALEJANDRO

PHYSICA SCRIPTA - (Print)

IOP PUBLISHING LTD

Lugar: Londres; Año: 2019

0031-8949

In this work, we study strategies for the optical control, within the dipole approximation, of a
 qubit encoded in the total intrinsic angular momentum states of three electrons confined in a triple
 quantum dot. The system is modeled using effective confining potentials, and its electronic structure
 is calculated using the configuration interaction method. Optimal control theory (OCT) was applied
 to design low-fluence time-dependent electric fields controlling the qubit in times shorter than a
 nanosecond. The resulting pulses produce transitions between the qubit states for experimentally
 available field amplitudes with high fidelity. Moreover, studying the dominant frequencies present
 in the OCT pulses, we show that the switching between the qubit states can also be achieved with
 simpler combinations of sinusoidal driving fields that produce transitions to intermediate states.
 The limitations of an extended Hubbard description for the model and its dynamic behaviour are
 also discussed.