Tunable Fermi-Edge Resonance in an Open Quantum Dot

TL;DR

This paper proposes using resonant tunneling in an open quantum dot to realize a tunable Fermi-edge resonance, linking the tunneling current behavior to the quantum dot's scattering properties and enabling exploration of various exponents.

Contribution

It introduces a method to control Fermi-edge resonances in quantum dots by tuning their shape and coupling, providing a new way to study mesoscopic transport phenomena.

Findings

Tunneling current exhibits power-law behavior linked to the S-matrix.

Control over dot shape and coupling allows tuning of the Fermi-edge resonance.

Transport properties mirror mesoscopic phenomena like weak localization.

Abstract

Resonant tunneling in an open mesoscopic quantum dot is proposed as a vehicle to realize a tunable Fermi-edge resonance with variable coupling strength. We solve the x-ray edge problem for a generic nonseparable scatterer and apply it to describe tunneling in a quantum dot. The tunneling current power law exponent is linked to the S-matrix of the dot. The control of scattering by varying the dot shape and coupling to the leads allows to explore a wide range of exponents. Transport properties, such as weak localization, mesoscopic conductance fluctuations, and sensitivity to Wigner-Dyson ensemble type, have their replicas in the Fermi-edge singularity.