Intrinsic Josephson effects in Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8+x/ single crystals

The authors report on microwave emission of Bi/sub 2/Sr/sub 2/Ca/sub 2/O/sub 8+x/ single crystals with current flow along the c-axis. The results show that a small Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8/ single crystal behaves like a series array of several thousand Josephson junctions which can exhibit mutual phase-locking. At least at low temperatures there is evidence for mutual phase locking between several tens of junctions. It is noted that improving the crystal quality should increase the number of phase-locked junctions and therefore provide the possibility of using such crystals as naturally grown high-frequency oscillators.<
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