Control of excitation transfer in coupled quantum dots by a nonresonant laser pulse

Quantum Computing with Exciton Qubits in Colloidal Semiconductor Nanocrystals

“…As we are going to show, logic gates could be performed by laser pulses with the same photon energy E L , detuned from individual dot resonances ( E L < E 1 , E 2 ), which significantly simplifies the experimental setup and reduces photobleaching (since detuned photons are not absorbed by nanocrystals). These laser pulses are designed to manipulate the Förster interaction ( V F ) between proximal dots through a Stark shift, Δ E Stark , resulting from the electric field of laser radiation. − The idea is to bring the system, initially prepared in the state |10⟩ into to a resonance with the neighboring dot, E 2 – E 1 = V F + Δ E Stark . This will induce Rabi oscillations between dots 1 and 2 and shift its eigenfunctions toward the state superposition: c 1 |10⟩ + c 2 |01⟩, c 1 |01⟩ – c 2 |10⟩.…”

High-fidelity quantum control via Autler-Townes splitting

“…Following the initial quantum preparation the final state transfer is driven by the internal Hamiltonian. Within this notresonant approach the quantum control based on laserinduced potentials, i.e., on AC Stark shift, in some context known as Autler-Townes splitting, [5], has received a widespread interest, from atomic-molecular physics [6][7][8][9] to solid state systems [10,11] and chemistry [12,13]. Within the atomic-molecular physics area such an approach has been applied to different processes as molecular alignment, photodissociation reactions, such as re-viewed in [9].…”