Low-temperature depinning of sliding charge-density waves

Recent experiments on ${\mathrm{K}}_{0.3}$Mo${\mathrm{O}}_3$ have accurately characterized two dramatic new features of charge-density wave (CDW) depinning at low temperatures: (1) CDW conductivity above the ordinary threshold field $E_T$ scales with the temperature-activated normal conductance ${\sigma }_{\mathrm{CDW}}\approx k{\sigma }_n\mathrm{}\left(T\right)\mathrm{}$, and (2) the CDW current rises abruptly by several orders of magnitude above a second threshold field $E_T^{*}\sim 100E_T$. These remarkable new phenomena are quantitatively interpreted using our recent strong-pinning model for CDW dynamics.