Fractional Little-Parks effect observed in a topological superconductor
| Autor: | Li, Yufan, Xu, Xiaoying, Lee, Shu-Ping, Chien, C. L. |
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| Rok vydání: | 2020 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | In superconductors, the condensation of Cooper pairs gives rise to fluxoid quantization in discrete units of $\Phi_0 = hc / 2e$. The denominator of $2e$ is the signature of electron pairing, which is evidenced by a number of macroscopic quantum phenomena, such as the Little-Parks effect and the Josephson effect, where the critical temperature or the critical current oscillates in the period of $\Phi_0$. Here we report the observation of fractional Little-Parks effect in mesoscopic rings of epitaxial $\beta$-Bi$_2$Pd, a topological superconductor. Besides $\Phi_0$, novel Little-Parks oscillation periodicities of $2\Phi_0$, $3\Phi_0$ and $4\Phi_0$ are also observed, implying quasiparticles with effective charges being a fraction of a Cooper pair. We show that the fractional Little-Parks effect may be closely related to the fractional Josephson effect, which is a key signature of chiral Majorana edge states. Comment: 30 pages total; 16 pages and 4 figures for the main text; 14 pages and 13 figures for the supplementary information |
| Databáze: | arXiv |
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