Exchange Coupling in a Linear Chain of Three Quantum-Dot Spin Qubits in Silicon

Kok Wai Chan, Harshad Sahasrabudhe, Wister Huang, Yu Wang, Henry C. Yang, Menno Veldhorst, Jason C.C. Hwang, Fahd A. Mohiyaddin, Fay E. Hudson, Kohei M. Itoh, Andre Saraiva, Andrea Morello, Arne Laucht, Rajib Rahman, Andrew S. Dzurak

研究成果: Article査読

19 被引用数 (Scopus)


Quantum gates between spin qubits can be implemented leveraging the natural Heisenberg exchange interaction between two electrons in contact with each other. This interaction is controllable by electrically tailoring the overlap between electronic wave functions in quantum dot systems, as long as they occupy neighboring dots. An alternative route is the exploration of superexchange - the coupling between remote spins mediated by a third idle electron that bridges the distance between quantum dots. We experimentally demonstrate direct exchange coupling and provide evidence for second neighbor mediated superexchange in a linear array of three single-electron spin qubits in silicon, inferred from the electron spin resonance frequency spectra. We confirm theoretically, through atomistic modeling, that the device geometry only allows for sizable direct exchange coupling for neighboring dots, while next-nearest neighbor coupling cannot stem from the vanishingly small tail of the electronic wave function of the remote dots, and is only possible if mediated.

ジャーナルNano Letters
出版ステータスPublished - 2021 2月 10

ASJC Scopus subject areas

  • バイオエンジニアリング
  • 化学一般
  • 材料科学一般
  • 凝縮系物理学
  • 機械工学


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