Indirect Coupling in a Cluster of Quantum-Dot-Based Charge Qubits

Abstract

We have theoretically studied a problem of the organization of controllable interactions among charge qubits in a three-qubit cluster. Our proposal is to use an auxiliary quantum dot structure that mediates interqubit coupling. A non-trivial evolution of the cluster is generated through the electromagnetically induced resonant single-electron conditional excitations in the structure. As we demonstrate, the two-and three-qubit operations CZ and CCZ based on conditional phase accumulation and, therefore, CNOT and Toffoli gates, can be performed with high accuracy in several steps at relatively short times.

Generation of spatially entangled states in a photonic molecule containing a quantum dot

“…Photon transport through the PM was found to be efficiently controlled both by choosing MR parameters and by applying external fields. Besides, in [29] a similar structure of an artificial molecule of four QDs with one electron was proposed to be used for fast implementation of the Toffoli gate based on three charge QD qubits. Each PM element performs its specific function: two MR ports (source and drain), the central MR (base), and a controlling MR (gate), which contains a quantum emitter or a qubit and can move relative to the base.…”