  Recent experiments show oscillations of dominant period h/2e in conductance
vs. magnetic flux of charge density wave (CDW) rings above 77 K, revealing
macroscopically observable quantum behavior. The time-correlated soliton
tunneling model discussed here is based on coherent, Josephson-like tunneling
of microscopic quantum solitons of charge 2e. The model interprets the CDW
threshold electric field as a Coulomb blockade threshold for soliton pair
creation, often much smaller than the classical depinning field but with the
same impurity dependence (e.g., ~ ni^2 for for weak pinning). This picture
draws upon the theory of time-correlated single-electron tunneling to interpret
CDW dynamics above threshold. Similar to Feynman's derivation of the Josephson
current-phase relation for a superconducting tunnel junction, the picture
treats the Schrodinger equation as an emergent classical equation to describe
the time-evolution of Josephson-coupled order parameters related to soliton
dislocation droplets. Vector or time-varying scalar potentials can affect the
order parameter phases to enable magnetic quantum interference in CDW rings or
lead to interesting behavior in response to oscillatory electric fields. The
ability to vary both magnitudes and phases is an aspect important to future
applications in quantum computing.
