基于应变锗空穴双量子点的可调耦合和自旋阻塞研究  

Study of Tunable Coupling and Hole Spin Blockade Based on Strained Germanium Double Quantum Dots

作　　者：刘洋 周雨晨 李海欧 郭国平[1,2] LIU Yang;ZHOU Yuchen;LI Haiou;GUO Guoping(CAS Key Laboratory of Quantum Information,University of Science and Technology of China,Hefei 230026,China;Origin Quantum Computing Company Limited,Hefei 230093,China)

机构地区：[1]中国科学技术大学,中国科学院量子信息重点实验室,合肥230026 [2]本源量子计算科技有限责任公司,合肥230093

出　　处：《低温物理学报》2023年第2期77-85,共9页Low Temperature Physical Letters

基　　金：国家自然科学基金(编号:12074368,92165207,12034018);安徽省杰出青年科学基金(编号:2108085J03)资助的课题。

摘　　要：应变锗空穴量子点是实现超大规模量子计算最有前景的平台之一.由于锗空穴不受超精细相互作影响,有着较长的自旋弛豫时间和量子退相干时间,且锗中本征的强旋轨道耦合和空穴载流子的低有效质量,使得全电场操控空穴自旋量子比特得以实现,极大地降低了器件加工难度,增加了量子点的可扩展性.本文介绍了一种使用应变锗异质结制备重叠栅空穴双量子点器件的方法,完成了应变锗异质结性质测量,空穴双量子点器件制作,单量子点输运性质和双量子点输运性质研究,双量子点耦合可研究调节性研究,以及外磁场存在下的漏电流性质研究和泡利自旋阻塞解除机制的研究.这些工作为未来实现高质量自旋量子比特制备和高保真度量子逻辑门操控提供了实验平台和基本参数.Strained Germanium hole quantum dots are onde of the most promising platforms for realizing large scale quantum computing.Since holes in germanium are not affected by hyperfine interaction,they have long spin relaxation time and quantum decoherence time.At the same time,the strong intrinsic spin-orbit coupling in germanium and the low effective mass of hole carriers enable all-electric field manipulation of hole spin qubit,which greatly reduces the fabrication difficulty of the quantum dot devices and increases the scalability of semiconductor quantum dots.In this paper,we introduce a method of fabricating overlapping gate hole double quantum dot devices1in strain germanium heterostructure,as well as the measurement of strain germanium heterostructure properties,the fabrication of hole double quantum dot devices,the study of single quantum dot and double quantum dots transport properties,the study of tunability of double quantum dot coupling,the study of leakage current properties when external magnetic field exists and the lift mechanism of Pauli spin blockade.Our work provides an experimental platform and basic parameters for the realization of high-quality spin qubit preparation and high-fidelity quantum logic gate manipulation in the future.

关 键 词：应变锗异质结 空穴量子点 泡利自旋阻塞 自旋轨道耦合 

分 类 号：O469[理学—凝聚态物理]