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Tunable Spin Qubit Coupling Mediated by a Multi-Electron Quantum Dot



Vanita Srinivasa, Haitan Xu, Jacob M. Taylor


We present an approach for entangling electron spin qubits localized on spatially separated impurity atoms or quantum dots via a multi-electron, two-level quantum dot. The effective exchange interaction mediated by the dot can be understood as the simplest manifestation of Ruderman- Kittel-Kasuya-Yosida exchange, and can be manipulated through gate voltage control of level splittings and tunneling amplitudes within the system. This provides both a high degree of tuneability and a means for realizing high-fidelity two-qubit gates between spatially separated spins, yielding an experimentally accessible method of coupling donor electron spins in silicon via a hybrid impurity-dot system.
Physical Review Letters


quantum dots, impurity atoms, exchange interaction, entanglement, two-qubit gate, phosphorus donors, silicon, electrical control, electron spin qubits


Srinivasa, V. , Xu, H. and Taylor, J. (2015), Tunable Spin Qubit Coupling Mediated by a Multi-Electron Quantum Dot, Physical Review Letters, [online], (Accessed May 26, 2024)


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Created June 4, 2015, Updated November 10, 2018