Authors

H. Minami; C. Watanabe; K. Sato; S. Sekimoto; T. Yamamoto; T. Kashiwagi; R. A. Klemm;K. Kadowaki

Comments

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Abbreviated Journal Title

Phys. Rev. B

Keywords

INTRINSIC JOSEPHSON-JUNCTIONS; SCANNING-ELECTRON-MICROSCOPY; T-C; SILICON-CARBIDE; RESOLUTION; HOTSPOTS; RADIATION; FILMS; Physics, Condensed Matter

Abstract

From the photoluminescence of SiC microcrystals uniformly covering a rectangular mesa of the high transition temperature T-c superconductor Bi2Sr2CaCu2O8+delta, the local surface temperature T(r) was directly measured during simultaneous sub-THz emission from the N similar to 10(3) intrinsic Josephson junctions (IJJs) in the mesa. At high bias currents I and low bath temperatures T-bath less than or similar to 35 K, the center of a large elliptical hot spot with T(r) > T-c jumps dramatically with little current-voltage characteristic changes. The hot spot does not alter the ubiquitous primary and secondary emission conditions: the ac-Josephson relation and the electromagnetic cavity resonance excitation, respectively. Since the most intense sub-THz emission was observed for high T-bath greater than or similar to 50 K in the low I bias regime where hot spots are absent, hot spots cannot provide the primary mechanisms for increasing the output power, the tunability, or promoting the synchronization of the N IJJs for the sub-THz emission, but can at best coexist nonmutualistically with the emission. No T(r) standing waves were observed.

Journal Title

Physical Review B

Volume

89

Issue/Number

5

Publication Date

1-1-2014

Document Type

Article

Language

English

First Page

9

WOS Identifier

WOS:000332374300004

ISSN

1098-0121

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