Single to quadruple quantum dots with tunable tunnel couplings

Journal Article · Mon Mar 17 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4869108· OSTI ID:22257709

Takakura, T.; Noiri, A.; Obata, T.; Yoneda, J.; Yoshida, K. ^[1]; Otsuka, T.; Tarucha, S. ^[1]

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1. Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

We prepare a gate-defined quadruple quantum dot to study the gate-tunability of single to quadruple quantum dots with finite inter-dot tunnel couplings. The measured charging energies of various double dots suggest that the dot size is governed by the gate geometry. For the triple and quadruple dots, we study the gate-tunable inter-dot tunnel couplings. For the triple dot, we find that the effective tunnel coupling between side dots significantly depends on the alignment of the center dot potential. These results imply that the present quadruple dot has a gate performance relevant for implementing spin-based four-qubits with controllable exchange couplings.

• OSTI ID: 22257709
• Journal Information: Applied Physics Letters, Vol. 104, Issue 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
GEOMETRY
QUANTUM DOTS
QUBITS
SPIN
TUNNELS