title: Tunable Spin-Qubit Coupling Mediated by a Multielectron Quantum Dot.
abstract: We present an approach for entangling electron spin qubits localized on spatially separated impurity atoms or quantum dots via a multielectron, 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 tunability 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.
authors.affiliation: Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA and National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
authors.forename: V
authors.initials: V
authors.lastname: Srinivasa
authors.affiliation: Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA and National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
authors.forename: H
authors.initials: H
authors.lastname: Xu
authors.affiliation: Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA and National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Taylor