Fermi edge singularities in transport through lateral GaAs quantum dots

Abstract

We measure tunnelling currents through electrostatically defined quantum dots in a GaAs/AlGaAs heterostructure connected to two leads. For certain tunnelling barrier configurations and high sample bias we find a pronounced resonance associated with a Fermi edge singularity. This many-body scattering effect appears when the electrochemical potential of the quantum dot is aligned with the Fermi level of the lead less coupled to the dot. By changing the relative tunnelling barrier strength we are able to tune the interaction of the localised electron with the Fermi sea.

Scaling of the Fermi‐Edge Singularity in Quantum Dots

“…It is known that the interaction due to the FES becomes stronger for reduced dimensions, which was studied for high magnetic fields and therefore effective 1D leads in ref. . Moreover the thickness of the tunneling barriers plays an important role.…”