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Interaction of hot spots and terahertz waves inBi2Sr2CaCu2O8intrinsic Josephson junction stacks of various geometry
- Source :
- Physical Review B. 82
- Publication Year :
- 2010
- Publisher :
- American Physical Society (APS), 2010.
-
Abstract
- At high enough input power in stacks of ${\text{Bi}}_{2}{\text{Sr}}_{2}{\text{CaCu}}_{2}{\text{O}}_{8}$ intrinsic Josephson junctions a hot spot (a region heated to above the superconducting transition temperature) coexists with regions being still in the superconducting state. In the ``cold'' regions cavity resonances can occur, synchronizing the ac Josephson currents and giving rise to strong and stable coherent terahertz (THz) emission. We investigate the interplay of hot spots and standing electromagnetic waves by low-temperature scanning laser microscopy and THz emission measurements, using stacks of various geometries. Standing electromagnetic wave patterns and THz emission are observed for a disk-shaped sample. The growth of a hot spot with increasing input power is monitored by small detector junctions surrounding a large rectangular mesa. For two rectangular mesas equipped with two current injectors and one arrow-shaped structure we show that the standing wave can be turned on and off in various regions of the stack structure, depending on the hot-spot position. The results support the picture of the hot spot acting as a reflective termination of the cavity, formed by the cold part of the mesa.
- Subjects :
- Josephson effect
Pi Josephson junction
Standing wave
Physics
Superconductivity
Stack (abstract data type)
Condensed matter physics
Terahertz radiation
Condensed Matter::Superconductivity
Hot spot (veterinary medicine)
Condensed Matter Physics
Electromagnetic radiation
Electronic, Optical and Magnetic Materials
Subjects
Details
- ISSN :
- 1550235X and 10980121
- Volume :
- 82
- Database :
- OpenAIRE
- Journal :
- Physical Review B
- Accession number :
- edsair.doi...........62519d903993f925f9bea62b03b8452a