28 research outputs found
Quantum Hall Transitions in (TMTSF)PF
We have studied the temperature dependence of the integer quantum Hall
transitions in the molecular crystal (TMTSF)PF. 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
risers, , and the (inverse) width of the peaks,
, 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.Comment: 10 pages, RevTeX, 4 PostScript figure
Spectral Properties of Three Dimensional Layered Quantum Hall Systems
We investigate the spectral statistics of a network model for a three
dimensional layered quantum Hall system numerically. The scaling of the
quantity is used to determine the critical exponent for
several interlayer coupling strengths. Furthermore, we determine the level
spacing distribution as well as the spectral compressibility at
criticality. We show that the tail of decays as with
and also numerically verify the equation
, where is the correlation dimension and the
spatial dimension.Comment: 4 pages, 5 figures submitted to J. Phys. Soc. Jp