Nonlinear magnetotransport and charge-density-wave motion inNbSe3at temperatures from 1.2 to 50 K

The transverse magnetoresistance of ${\mathrm{NbSe}}_3$ at 1.2 K shows a large non-Ohmic reduction as a function of electric field for magnetic fields in the range 50–230 kG. The magnetoresistance data in the temperature range 1.2–43 K has been fitted to a Zener-tunneling model of the form σ=${\sigma }_a$(H)+${\sigma }_b$(1-$E_T$/E)exp( -$E_0$/E) and gives a value of $E_0$=0.47 V/cm and $E_T$=0.066 V/cm at 1.2 K and 206 kG for a crystal with a residual resistance ratio of 145. At 206 kG $E_0$ follows a temperature dependence of the form $E_0$(T)=$E_0$(0)exp(-$k_B$T/Δ) with Δ/$k_B$=15.2 K. The threshold electric field for charge-density-wave (CDW) motion is reduced at high magnetic fields and low temperatures while the magnetoresistance behavior suggests that the CDW structure below 59 K is strongly coupled to the magnetic field.