Fractional quantum Hall interferometers in a strong tunneling regime: The role of compactness in edge fields

We consider multiple-point tunneling in the interferometers formed between edges of electron liquids with, in general, different filling factors in the regime of the fractional quantum Hall effect (FQHE). We derive an effective matrix Caldeira-Leggett model for the multiple tunneling contacts connecting the chiral single-mode FQHE edges. It is shown that the compactness of the Wen-Fröhlich chiral boson fields describing the FQHE edge modes plays a crucial role in eliminating the spurious nonlocality of the electron transport properties of the FQHE interferometers arising in the regime of strong tunneling.