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Sunday, May 8, 2016
Abstract-Three-Dimensional Simulations of the Electrothermal and Terahertz Emission Properties of Bi2Sr2CaCu2O8 Intrinsic Josephson Junction Stacks
F. Rudau, R. Wieland, J. Langer, X. J. Zhou, M. Ji, N. Kinev, L. Y. Hao, Y. Huang, J. Li, P. H. Wu, T. Hatano, V. P. Koshelets, H. B. Wang, D. Koelle, and R. Kleiner
Phys. Rev. Applied 5, 044017 – Published 27 April 2016
We use 2D coupled sine-Gordon equations combined with 3D heat diffusion equations to numerically investigate the thermal and electromagnetic properties of a 250×70μm2intrinsic Josephson junction stack. The 700 junctions are grouped to 20 segments; we assume that in a segment all junctions behave identically. At large input power, a hot spot forms in the stack. Resonant electromagnetic modes oscillating either along the length [(0, n) modes] or the width [(m, 0) modes] of the stack or having a more complex structure can be excited both with and without a hot spot. At fixed bath temperature and bias current, several cavity modes can coexist in the absence of a magnetic field. The (1, 0) mode considered to be the most favorable mode for terahertz emission can be stabilized by applying a small magnetic field along the length of the stack. A strong field-induced enhancement of the emission power is also found in experiment for an applied field around 5.9 mT.