<i>h</i>/<i>e</i> oscillations in interlayer transport of delafossites.

Putzke, Carsten; Bachmann, Maja D; McGuinness, Philippa; Zhakina, Elina; Sunko, Veronika; Konczykowski, Marcin; Oka, Takashi; Moessner, Roderich et al. · Science · 2020

basic_science · Level V

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Abstract

Microstructures can be carefully designed to reveal the quantum phase of the wave-like nature of electrons in a metal. Here, we report phase-coherent oscillations of out-of-plane magnetoresistance in the layered delafossites PdCoO<sub>2</sub> and PtCoO<sub>2</sub> The oscillation period is equivalent to that determined by the magnetic flux quantum, <i>h/e</i>, threading an area defined by the atomic interlayer separation and the sample width, where <i>h</i> is Planck's constant and <i>e</i> is the charge of an electron. The phase of the electron wave function appears robust over length scales exceeding 10 micrometers and persisting up to temperatures of T > 50 kelvin. We show that the experimental signal stems from a periodic field modulation of the out-of-plane hopping. These results demonstrate extraordinary single-particle quantum coherence lengths in delafossites.