Room-Temperature Defect Qubits in Ultrasmall Nanocrystals

Dávid Beke, Jan Valenta, Gyula Károlyházy, Sándor Lenk, Zsolt Czigány, Bence Gábor Márkus, Katalin Kamarás, Ferenc Simon, Adam Gali

Research output: Contribution to journalArticle


There is an urgent quest for room-temperature qubits in nanometer-sized, ultrasmall nanocrystals for quantum biosensing, hyperpolarization of biomolecules, and quantum information processing. Thus far, the preparation of such qubits at the nanoscale has remained futile. Here, we present a synthesis method that avoids any interaction of the solid with high-energy particles and uses self-propagated high-temperature synthesis with a subsequent electrochemical method, the no-photon exciton generation chemistry to produce room-temperature qubits in ultrasmall nanocrystals of sizes down to 3 nm with high yield. We first create the host silicon carbide (SiC) crystallites by high-temperature synthesis and then apply wet chemical etching, which results in ultrasmall SiC nanocrystals and facilitates the creation of thermally stable defect qubits in the material. We demonstrate room-temperature optically detected magnetic resonance signal of divacancy qubits with 3.5% contrast from these nanoparticles with emission wavelengths falling in the second biological window (1000-1380 nm). These results constitute the formation of nonperturbative bioagents for quantum sensing and efficient hyperpolarization.

Original languageEnglish
Pages (from-to)1675-1681
Number of pages7
JournalJournal of Physical Chemistry Letters
Issue number5
Publication statusPublished - Mar 5 2020

ASJC Scopus subject areas

  • Materials Science(all)
  • Physical and Theoretical Chemistry

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