Indirect control with quantum accessor: coherent control by initial state preparation

TL;DR

This paper introduces a novel indirect quantum control scheme that manipulates the initial state of a quantum accessor to control a system, demonstrating controllability through theoretical proof and a spin qubit example.

Contribution

It proposes a new indirect quantum control method based on initial accessor state preparation, differing from previous interaction manipulation approaches.

Findings

Proves controllability of the controlled system under the new scheme

Demonstrates the scheme with a two-spin qubit example

Shows the effectiveness of initial state preparation for quantum control

Abstract

This is the second one in our series of papers on indirect quantum control assisted by quantum accessor. In this paper we propose and study a new class of indirect quantum control(IDQC) scheme based on the initial states preparation of the accessor. In the present scheme, after the initial state of the accessor is properly prepared, the system is controlled by repeatedly switching on and off the interaction between the system and the accessor. This is different from the protocol of our first paper, where we manipulate the interaction between the controlled system and the accessor. We prove the controllability of the controlled system for the proposed indirect control scheme. Furthermore, we give an example with two coupled spins qubits to illustrate the scheme, the concrete control process and the controllability.