Time-correlated Tunneling Research Articles

Time-correlated tunneling of solitons in charge and spin density waves

We consider a model in which an electric field induces quantum nucleation of kink-antikink pairs in a charge or spin density wave. Pair nucleation events, prevented by the electrostatic energy below a pair creation threshold, become correlated in time above threshold. The model provides a natural explanation for the observed small density wave displacement below threshold, narrow-band noise, coherent oscillations, and mode-locking at high drift frequencies.

Theory of time-correlated tunneling of density wave solitons

We discuss a model in which an applied field induces quantum nucleation of soliton-antisoliton (S-S') pairs in a pinned charge or spin density wave. Coulomb blockade prevents pair creation until the electric field exceeds a sharp threshold value, which can be much smaller than the classical depinning field. Above threshold, the pair creation events become correlated in time, by analogy to time-correlated single electron tunneling. We compute the phase polarization and find that, depending on parameters, the predicted phase polarization can either be extremely small below threshold, as observed in NbSe 3 , or quite substantial, as observed in blue bronze. The lack of significant phase polarization below threshold in NbSe 3 , indicated by several experiments, suggests that the measured threshold field is a quantum S-S' pair creation threshold rather than a classical depinning field.