Nanophysics corresponds to physics at the scale of the nanometre, a billionth of a metre, or a hundred thousandth of the width of a hair. It corresponds to the size of about ten atoms.
What happens when the size of a superconductor is decreased to a few billionths of a metre? Thanks to technological progress and a little cleverness, it is now possible to conduct such experiments in laboratories. We have hence discovered that superconductivity survives at the scale of the nanometre, in metals and some nanomaterials such as carbon nanotubes.
It has been proved that superconductivity can be observed in a small piece of aluminium of only a thousand atoms. Superconductivity even exists in carbon nanotubes, which are a few hundred nanometre long but only have a one-nanometre diameter!
Observing and manipulating superconductivity at the scale of the nanometre is one of the issues of modern research, not only to understand superconductivity better, but also to make non-superconducting materials superconducting, or to invent new electronic components with very strange properties.
Graphene and superconductivity
Zooming in with an electron scanning microscope on a graphene sheet sprinkled with superconducting nanoparticles (made of indium). The scale bar goes from millimeters to nanometres.
Copyright : groupe de Physique Mésoscopique, LPS Orsay
Nanosquid
Zooming in on a nanoSQUID. This nanoSQUID is made of a superconducting loop (of niobium) interrupted by two non superconducting (normal) wires, made of gold. At low temperature a supercurrent runs through the gold wires, and the interference between the two branches is modulated by a magnetic field.
Copyright : groupe de Physique Mésoscopique, LPS Orsay
Nanotubes and superconductivity
At the heart of this chip is a carbon nanotube connected to two superconducting electrodes, with nearby a third electrode which controls the parity of electrons in the nanotubes and modulates the supercurrent through the tube.
Copyright : groupe de Physique Mésoscopique, LPS Orsay
