title: Efficient room-temperature nuclear spin hyperpolarization of a defect atom in a semiconductor.
abstract: Nuclear spin hyperpolarization is essential to future solid-state quantum computation using nuclear spin qubits and in highly sensitive magnetic resonance imaging. Though efficient dynamic nuclear polarization in semiconductors has been demonstrated at low temperatures for decades, its realization at room temperature is largely lacking. Here we demonstrate that a combined effect of efficient spin-dependent recombination and hyperfine coupling can facilitate strong dynamic nuclear polarization of a defect atom in a semiconductor at room temperature. We provide direct evidence that a sizeable nuclear field (~150 Gauss) and nuclear spin polarization (~15%) sensed by conduction electrons in GaNAs originates from dynamic nuclear polarization of a Ga interstitial defect. We further show that the dynamic nuclear polarization process is remarkably fast and is completed in <5 μs at room temperature. The proposed new concept could pave a way to overcome a major obstacle in achieving strong dynamic nuclear polarization at room temperature, desirable for practical device applications.
authors.affiliation: Department of Physics, Chemistry and Biology, Linköping University, S-581 83 Linköping, Sweden.
authors.forename: Y
authors.initials: Y
authors.lastname: Puttisong
authors.forename: X J
authors.initials: XJ
authors.lastname: Wang
authors.forename: I A
authors.initials: IA
authors.lastname: Buyanova
authors.forename: L
authors.initials: L
authors.lastname: Geelhaar
authors.forename: H
authors.initials: H
authors.lastname: Riechert
authors.forename: A J
authors.initials: AJ
authors.lastname: Ptak
authors.forename: C W
authors.initials: CW
authors.lastname: Tu
authors.forename: W M
authors.initials: WM
authors.lastname: Chen