Superconducting Josephson Cantilevers for THz Microscopy

Josephson cantilevers based on superconducting Josephson junctions can be used for the measurement of frequency and power of microwave and terahertz radiation. For this, Josephson junctions made from the high-temperature superconductor YBa
₂
Cu
₃
O
₇
are deployed on MgO bicrystal substrates. These Josephson cantilevers are utilized as detectors in our THz microscope. An adjustable current is injected into the junction and the current-voltage characteristic is recorded to derive the frequency and the power of an external radiation from the characteristic. To achieve spatial resolution with the THz microscope, the Josephson cantilever is mounted on a three-dimensional positioning system.