Coherent coupling between a quantum dot and a donor in silicon. Issue 1 (December 2017)

• Record Type: Journal Article
• Authors: Harvey-Collard, Patrick; Jacobson, N. Tobias; Rudolph, Martin; Dominguez, Jason; Ten Eyck, Gregory; Wendt, Joel; Pluym, Tammy; Gamble, John; Lilly, Michael; Pioro-Ladrière, Michel; Carroll, Malcolm
• Is Part Of: Nature communications. Volume 8:Issue 1(2017)
• Page Start: 1
• Page End: 6
• Publication Date: 2017-12
• Subjects: Biology -- Periodicals; Physical sciences -- Periodicals; 505
• DOI: 10.1038/s41467-017-01113-2
• Languages: English
• ISSNs: 2041-1723

Abstract

Abstract Individual donors in silicon chips are used as quantum bits with extremely low error rates. However, physical realizations have been limited to one donor because their atomic size causes fabrication challenges. Quantum dot qubits, in contrast, are highly adjustable using electrical gate voltages. This adjustability could be leveraged to deterministically couple donors to quantum dots in arrays of qubits. In this work, we demonstrate the coherent interaction of a31 P donor electron with the electron of a metal-oxide-semiconductor quantum dot. We form a logical qubit encoded in the spin singlet and triplet states of the two-electron system. We show that the donor nuclear spin drives coherent rotations between the electronic qubit states through the contact hyperfine interaction. This provides every key element for compact two-electron spin qubits requiring only a single dot and no additional magnetic field gradients, as well as a means to interact with the nuclear spin qubit. In silicon, quantum information can be stored in donors or quantum dots, each with its advantages and limitations—particularly in terms of fabrication. Here the authors coherently couple a phosphorous donor's electron spin to a quantum dot, encoding information in the hybrid two-electron system's state.