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Thermal management in large Bi2212 mesas used for terahertz sources.

Conference · · IEEE Trans. Appl. Supercond.

We present a thermal analysis of a patterned mesa on a Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} (Bi2212) single crystal that is based on tunneling characteristics of the c-axis stack of {approx}800 intrinsic Josephson junctions in the mesa. Despite the large mesa volume (e.g., 40 times 300 times 1.2 mum{sup 3}) and power dissipation that result in self-heating and backbending of the current-voltage curve (I-V), there are accessible bias conditions for which significant polarized THz-wave emission can be observed. We estimate the mesa temperature by equating the quasiparticle resistance, R{sub qp}(T), to the ratio V/I over the entire I-V including the backbending region. These temperatures are used to predict the unpolarized black-body radiation reaching our bolometer and there is substantial agreement over the entire I-V. As such, backbending results from the particular R{sub qp}(T) for Bi2212, as first discussed by Fenton, rather than a significant suppression of the energy gap. This model also correctly predicts the observed disappearance of backbending above {approx}60 K.

Research Organization:
Argonne National Laboratory (ANL)
Sponsoring Organization:
SC; Japan Science and Technology Agency; Japan Society for the Promotion of Science; MEXT - Japan; Scientific and Technical Research Council of Turkey
DOE Contract Number:
AC02-06CH11357
OSTI ID:
962552
Report Number(s):
ANL/MSD/CP-62522
Journal Information:
IEEE Trans. Appl. Supercond., Journal Name: IEEE Trans. Appl. Supercond. Journal Issue: 3 ; Jun. 2009 Vol. 19
Country of Publication:
United States
Language:
ENGLISH