Quantum sensing of a coherent single spin excitation in a nuclear ensemble

• Published in: arXiv.org
• Main Authors: Jackson, Daniel M, Gangloff, Dorian A, Bodey, Jonathan H, Zaporski, Leon, Bachorz, Clara, Clarke, Edmund, Hugues, Maxime, Claire Le Gall, Atatüre, Mete
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 21.08.2020
• Subjects: Coherence; Electron spin; Electrons; Excitation; Magnons; Physics - Mesoscale and Nanoscale Physics; Physics - Quantum Physics; Polarity; Quantum dots; Quantum phenomena; Qubits (quantum computing)
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2008.09541

The measurement of single quanta in a collection of coherently interacting objects is transformative in the investigations of emergent quantum phenomena. An isolated nuclear-spin ensemble is a remarkable platform owing to its coherence, but detecting its single spin excitations has remained elusive. Here, we use an electron spin qubit in a semiconductor quantum dot to sense a single nuclear-spin excitation (a nuclear magnon) with 1.9-ppm precision via the 200-kHz hyperfine shift on the 28-GHz qubit frequency. We demonstrate this single-magnon precision across multiple modes identified by nuclear species and polarity. Finally, we monitor the coherent dynamics of a nuclear magnon and the emergence of quantum correlations competing against decoherence. A direct extension of this work is to probe engineered quantum states of the ensemble including long-lived memory states.