Quantum Hall Transitions in (TMTSF)\(_2\)PF\(_6\)

We have studied the temperature dependence of the integer quantum Hall transitions in the molecular crystal (TMTSF)\(_2\)PF\(_6\). We find that the transition width between the quantum Hall plateaus does not exhibit the universal power-law scaling behavior of the integer quantum Hall effect observed in semiconducting devices. Instead, the slope of the \(\rho_{xy}\) risers, \(d\rho_{xy}/dB\), and the (inverse) width of the \(\rho_{xx}\) peaks, \((\Delta B)^{-1}\), show a BCS-like energy gap temperature dependence. We discuss these results in terms of the field-induced spin-density wave gap and order parameter of the system.