Read-out and Dynamics of the Qubit Built on Three Quantum Dots

Abstract: We present a model of a qubit built of a three coherently coupled quantum dots with three spins in a triangular geometry. The qubit states are encoded in the doublet subspace and they are controlled by a gate voltage, which breaks the triangular symmetry of the system. We show how to prepare the qubit and to perform one qubit operations. A new type of the current blockade effect will be discussed. The blockade is related with an asymmetry of transfer rates from the electrodes to different doublet states and is used to read-out of the dynamics of the qubit state. Our research also presents analysis of the Rabi oscillations, decoherence and leakage processes in the doublets subspace.