Effect on ion-trap quantum computers from the quantum nature of the driving field

作     者：Biyao YANG Li YANG Biyao YANG;Li YANG

作者机构：State Key Laboratory of Information SecurityInstitute of Information EngineeringChinese Academy of Sciences State Key Laboratory of Cryptology School of Cyber SecurityUniversity of Chinese Academy of Sciences 

出 版 物：《Science China(Information Sciences)》 (中国科学:信息科学(英文版))

年 卷 期：2020年第63卷第10期

页      面：219-233页

核心收录：

学科分类：0810[工学-信息与通信工程] 0808[工学-电气工程] 07[理学] 08[工学] 070201[理学-理论物理] 081201[工学-计算机系统结构] 0812[工学-计算机科学与技术（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：supported by National Natural Science Foundation of China (Grant No. 61672517) National Cryptography Development Fund (Grant No. MMJJ20170108) National Key R&D Program of China (Grant No. 2016QY03D0503) Beijing Municipal Science & Technology Commission (Grant No. Z191100007119006) 

主　　题：quantum computing ion-trap quantum algorithm fault-tolerant quantum computation threshold theorem permitted depth of logical operation 

摘      要：In this study, we evaluate the effect on ion-trap quantum computers（QCs） from the quantum nature of the driving field, and propose a theoretical limit for ion-trap QCs that may impact the design of quantum algorithms and realization of practical QCs. We obtain, for the first time, the permitted depth of logical operation for fault-tolerant ion-trap QCs. Physically, we provide an exact（full-quantum） description of the QC system, and present for the first time its time evolution after gate operations; mathematically,we solve problems such as certain summations of trigonometric series with any given precision. Comparing the actual state after CNOT gates driven by a quantized field with the expected state, we obtain the failure probability and estimate that the number of CNOT gates on the same pair of physical qubits is not more than 10;in one error-correction period, which is a physical limit that cannot be easily overcome. The conclusion can help determine the number of CNOT operations between coding and decoding in one error-correction period and can be used as a reference for quantum algorithm design.