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Charge-state conditional operation of a spin qubit.

Research paper by I I van Weperen, B D BD Armstrong, E A EA Laird, J J Medford, C M CM Marcus, M P MP Hanson, A C AC Gossard

Indexed on: 16 Aug '11Published on: 16 Aug '11Published in: Physical review letters



Abstract

We report coherent operation of a singlet-triplet qubit controlled by the spatial arrangement of two confined electrons in an adjacent double quantum dot that is electrostatically coupled to the qubit. This four-dot system is the specific device geometry needed for two-qubit operations of a two-electron spin qubit. We extract the strength of the capacitive coupling between qubit and adjacent double quantum dot and show that the present geometry allows fast conditional gate operation, opening pathways toward implementation of a universal set of gates for singlet-triplet spin qubits.