Evidence of Nonlocal Breakdown of the Integer Quantum Hall Effect

Current induced breakdown of the integer quantum Hall effect (QHE) is studied in GaAs $/$AlGaAs single heterostructure Hall bars at $T=1.6\mathrm{}$–4.2 K and $B=2\mathrm{}$–6 T ( $\nu =2\mathrm{}$, 4, and 6). The QHE breakdown is absent over a macroscopic region in the two-dimensional electron gas channel on the side of the electron-injecting corner of the Hall bars. The observed nonlocal nature suggests that bootstrap-type electron heating is relevant to the QHE breakdown.