BGU Physics Department
# Colloquium, Oct. 28, 2010

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Superconductivity-superinsulation
duality

Superconductivity rests on two cornerstones:
(i) all electrons in a superconductor are described by a unique macroscopic wave
function and (ii) the phase of this wave function is well-defined over the whole
superconducting system, i.e. superconductivity is a quantum macroscopic state
maintaining the global phase coherence. The phase and the absolute value of the
wave function are canonically conjugated quantum variables, thus uncertainties
in the phase D*φ *
and in the condensed particle
number, D*N*,
are coupled by the Heisenberg relation D*φ*D*N *
~ 1.
This implies the existence of the superinsulating state dual to
superconducting one and possessing zero conductivity at finite temperatures. We
review realizations of the superinsulating state in two-dimensional disordered
superconducting films and Josephson junction arrays and discuss microscopic
mechanism that ensures superinsulating behavior: the cascade relaxation.