Superconductor-insulator transition and energy localization

The Superconductor Insulator Transition

As the thickness or magnetic field is varied in thin films a transition between superconducting and insulating phases takes place. This quantum phase transition obeys scaling relations and occurs at seemingly universal critical resistance. This paper reviews experiments that demonstrate this transition and measure the critical exponents. The microscopic theories are outlined and lead to differe...

Compensation-driven superconductor-insulator transition

The superconductor-insulator transition in the presence of strong compensation of dopants was recently realized in La doped yttrium barium copper oxide. The compensation of acceptors by donors makes it possible to change independently the concentration of holes n and the total concentration of charged impurities N. We propose a theory of the superconductor-insulator phase diagram in the N ,n pl...

Sharp superconductor-insulator transition in short wires.

Recent experiments on short MoGe nanowires show a sharp superconducting-insulating transition at the universal resistance R(Q)=h/(4e(2)), contrary to the expectation of a smooth temperature dependence of the resistance for such Josephson-like systems. We present a self-consistent renormalization-group treatment of interacting quantum phase slips in short superconducting wires, which reproduces ...

Spin Effects Near the Superconductor-Insulator Transition

Superconductor-insulator transition in long MoGe nanowires.

The properties of one-dimensional superconducting wires depend on physical processes with different characteristic lengths. To identify the process dominant in the critical regime we have studied the transport properties of very narrow (9-20 nm) MoGe wires fabricated by advanced electron-beam lithography in a wide range of lengths, 1-25  μm. We observed that the wires undergo a superconductor-i...