• 文献标题:   Quantum dots and spin qubits in graphene
  • 文献类型:   Review
  • 作  者:   RECHER P, TRAUZETTEL B
  • 作者关键词:  
  • 出版物名称:   NANOTECHNOLOGY
  • ISSN:   0957-4484 EI 1361-6528
  • 通讯作者地址:   Univ Wurzburg
  • 被引频次:   87
  • DOI:   10.1088/0957-4484/21/30/302001
  • 出版年:   2010

▎ 摘  要

This is a review on graphene quantum dots and their use as a host for spin qubits. We discuss the advantages but also the challenges to use graphene quantum dots for spin qubits as compared to the more standard materials like GaAs. We start with an overview of this young and fascinating field and then discuss gate-tunable quantum dots in detail. We calculate the bound states for three different quantum dot architectures where a bulk gap allows for confinement via electrostatic fields: (i) graphene nanoribbons with armchair boundaries, (ii) a disc in single-layer graphene, and (iii) a disc in bilayer graphene. In order for graphene quantum dots to be useful in the context of spin qubits, one needs to find reliable ways to break the valley degeneracy. This is achieved here, either by a specific termination of graphene in (i) or in (ii) and (iii) by a magnetic field, without the need of a specific boundary. We further discuss how to manipulate spin in these quantum dots and explain the mechanism of spin decoherence and relaxation caused by spin-orbit interaction in combination with electron-phonon coupling, and by hyperfine interaction with the nuclear-spin system.