THz・wave emission from inner l・V branches of intrinsic Josephson junctionsin Bi2Sr2CaCu2O8+s
THz・wave emission from inner l・V branches of intrinsic Josephson junctionsin Bi2Sr2CaCu2O8+s
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Bi2Sr2CaCu2O8+s 中本征约瑟夫森结的内部 l・V 分支发射太赫兹波
DOI：
10.1088/1742-6596/400/2/022127
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
K. Kadowaki
中科院分区：
文献类型：
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作者：
M.Tsujimoto;T.Yamamoto;K.Delfanazari;R. Nakayama;N.Orita;T.Koike;K.Deguchi;T.Kashiwagi;H.Minami;K. Kadowaki
我们观察到单晶bi2sr2cacu2o8 + δ台地结构的本征约瑟夫森结在太赫兹频率下发出强烈、连续和单色的电磁波，这些电磁波发生在电流-电压特性的多个分支结构深处。采用聚焦离子束铣削法，对近方形的矩形槽型台面样品进行了测量。在电流-电压测量过程中，同时进行发射太赫兹波的探测和红外光谱仪的光谱测量以获得辐射频率。通过扫描特定支路上的电压，我们观察到辐射频率的变化范围比传统腔谐振条件下的预期范围要宽，并且频率服从交流约瑟夫森关系，其中约瑟夫森频率与电压普遍成正比。这些实验事实可以为我们理解本征约瑟夫森结发射太赫兹波的机理提供重要的信息，以便在许多实际应用中利用它们作为有用的太赫兹源。
We have observed emissions of intense, continuous and monochromatic EM waves at THz frequencies from intrinsic Josephson junctions in the single crystalline Bi 2 Sr 2 CaCu 2 O 8+ δ mesa structure, which take place deep inside the multiple branch structures of the current-voltage characteristics. We measured a rectangular groove-type mesa sample with a nearly square shape fabricated by focused ion beam milling. The detection of emitted THz-waves and the spectroscopic measurement by the FT-IR spectrometer for obtaining the radiation frequency were performed simultaneously during the current-voltage measurement. By sweeping the voltage on a particular branch, we have observed that the radiation frequency varied in a relatively wider range than expected from the conventional cavity resonance condition, and that the frequency obeys the ac Josephson relation, in which the Josephson frequency is universally proportional to the voltage. These experimental facts may provide us significant information to understand the mechanism of the THz-wave emission from intrinsic Josephson junctions in order to make use of them as useful THz sources for many practical applications.