The quantum Hall effect in organic metals with both quasi-two-dimensional and quasi-one-dimensional Fermi-surface components

The quantum Hall effect (QHE) is shown to be a natural property in high magnetic fields of any system possessing both quasi-two-dimensional and quasi-one-dimensional Fermi-surface components. Such Fermi surfaces are known to occur in some organic charge-transfer salts (e.g. alpha-(BEDT-TTF)(2)MHg(SCN)(4) with M = K, Tl, NH4). Whilst the QHE in two-dimensional semiconductor systems such as heterostructures and MOSFETs relies on the existence of localized states at the edges of the Landau levels, in organic metals the quasi-one-dimensional portion of the Fermi surface is shown to provide the necessary reservoir for pinning the chemical potential between the completely filled and empty Landau levels of the quasi-two-dimensional Fermi-surface section.