Enhancement of Josephson Phase Diffusion by Microwaves

Koval, Yu; Fistul, Mikhail V.; Ustinov, Alexey V.

Abstract:
We report an experimental and theoretical study of the phase diffusion in small Josephson junctions under microwave irradiation. A peculiar enhancement of the phase diffusion by microwaves is observed. The enhancement manifests itself by a pronounced current peak in the current-voltage characteristics. The voltage position ${V}_{\mathrm{top}}$ of the peak increases with the power $P$ of microwave radiation as ${V}_{\mathrm{top}} {\propto}\sqrt{P}$, while its current amplitude weakly decreases with $P$. As the microwave frequency increases, the peak feature evolves into Shapiro steps with a finite slope. Our theoretical analysis, taking into account the enhancement of incoherent superconducting current by multiphoton absorption, is in good agreement with experimental data.

 Zugehörige Institution(en) am KIT Physikalisches Institut (PHI) Publikationstyp Zeitschriftenaufsatz Jahr 2004 Sprache Englisch Identifikator ISSN: 0031-9007, 1079-7114, 1092-0145 KITopen-ID: 1000074283 Erschienen in Physical review letters Band 93 Heft 8 Seiten Art. Nr. 087004 Nachgewiesen in Web of ScienceScopus
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