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

TL;DR

This paper models a qubit based on three coherently coupled quantum dots arranged in a triangle, exploring control, read-out, and dynamics including Rabi oscillations and decoherence.

Contribution

It introduces a novel qubit implementation using a three-dot system with symmetry-breaking control and analyzes its read-out and dynamic properties.

Findings

Demonstrates qubit preparation and operation methods.

Identifies a new current blockade effect for read-out.

Analyzes Rabi oscillations, decoherence, and leakage in the system.

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.