Emission of coherent THz radiation from superconductors
Emission of coherent THz radiation from superconductors
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DOI：
10.1126/science.1149802
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发表时间：
2007-11-23
期刊：
影响因子：
56.9
通讯作者：
Welp, U.
中科院分区：
文献类型：
--
作者：
Ozyuzer, L.;Koshelev, A. E.;Welp, U.
人们正在寻找紧凑型固态太赫兹(THz)辐射源，用于物理和生物科学中的传感、成像和光谱应用。我们证明了在层状高温超导体Bi2Sr2CaCu2O8中，可以从本征约瑟夫森结中提取出功率相当大的相干连续波太赫兹辐射。与激光腔类似，样品内部电磁腔共振的激发产生宏观相干态，在这种相干态中，大量的结被同步以同相振荡。在频率为0.85太赫兹的情况下，发射功率随结点数的平方增加，达到0.5微瓦，并保持到接近50Kelvin。这些结果应该会刺激太赫兹辐射的超导紧凑源的发展。
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 Bi2Sr2CaCu2O8. 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 similar to 50 kelvin. These results should stimulate the development of superconducting compact sources of THz radiation.