Since superconductors have been discovered in 1911 by Kammerlingh Onnes,
a wide range of very exciting research has been conducted to understand
their unique properties.
It has led to a broad range of unexpected
applications of superconductors in various fields, ranging from Metrology
with the voltage standard, to Medicine with magneto- cardiography or
One can also mention ultra-high sensitivity sensors for Astrophysics
or Geophysics, among many other applications.
One important field for which superconductors
present unique and unsurpassed features is called Superconductive Electronics.
This field can be divided in three parts:
Superconductive Digital Electronics (SDE), which is based on the
generation, propagation and processing of quanta of magnetic flux,
called fluxons. With SDE, the digital bit ("0" or "1")
is carried with fluxons, whose value is quantized. This quantization
allows to perform some functions which are very difficult to achieve
with traditional Electronics based on Semiconductors. Moreover,
the clock frequency of superconductive digital circuits can reach
several tens to several hundreds of GHz, with a very low consumption,
due to the zero resistance of superconductors.
- Superconductive sensors which are used on everyday basis in Medicine,
Astrophysics, Geophysics or in low-temperature Physics, due to their
unsurpassed sensitivity. Among them, Superconducting Quantum Interference Devices (SQUIDs) are used in several applications as, for instance, magnetometers, amplifiers or for inductance diagnostic purposes.
- Microwave devices, like filters that present high quality factors, as well as low-loss transmission lines that are necessary to propagate signals between superconducting or semiconducting active devices. Active microwave devices include SIS mixers, Hot Electron Bolometers or Long Josephson Junctions used as microwave oscillators, as a few examples.