Emission of Coherent THz Radiation from Superconductors
Compact solid-state sources of terahertz (THz) radiation are being sought for sensing, imaging, and spectroscopy applications across the physical and biological sciences. We demonstrate that coherent continuous-wave THz radiation of sizable power can be extracted from intrinsic Josephson junctions in the layered high-temperature superconductor Bi2Sr2CaCu 2O8. In analogy to a laser cavity, the excitation of an electromagnetic cavity resonance inside the sample generates a macroscopic coherent state in which a large number of junctions are synchronized to oscillate in phase. The emission power is found to increase as the square of the number of junctions reaching values of 0.5 microwatt at frequencies up to 0.85 THz, and persists up to ~50 kelvin. These results should stimulate the development of superconducting compact sources of THz radiation.
L. Ozyuzer and A. E. Koshelev and C. Kurter and N. S. Gopalsami and Q. Li and M. Tachiki and K. Kadowaki and T. Yamamoto and H. Minami and H. Yamaguchi and T. Tachiki and K. E. Gray and W. Kwok and U. W. Welp, "Emission of Coherent THz Radiation from Superconductors," Science, vol. 318, no. 5854, pp. 1291-1293, American Association for the Advancement of Science, Nov 2007.
The definitive version is available at http://dx.doi.org/10.1126/science.1149802
Geosciences and Geological and Petroleum Engineering
Keywords and Phrases
electromagnetic field; emission; radiance; superconductivity; electromagnetic radiation; high temperature procedures; laser; priority journal; solid state; superconductor; terahertz spectroscopy; thermal conductivity
International Standard Serial Number (ISSN)
Article - Journal
© 2007 American Association for the Advancement of Science, All rights reserved.