Many-body blockade of resonant tunneling of two-dimensional electrons

In high magnetic fields tunneling of two-dimensional electrons requires an extra energy to overcome an effective barrier due to electron-electron interaction. This barrier is clearly visible as a shift of the tunnel resonance to higher biases. The filling factor ν=1 marks a surprisingly rapid transition between low-field (quadratically developing shift) and high-field (saturation) regimes. At low temperatures, the many-body shift decays linearly with increasing temperature, which can be attributed to coupling of a tunneling electron to phononlike excitations in the correlated electron system.