Ultrafast Emission and Detection of a Single-Electron Gaussian Wave Packet: A Theoretical Study

TL;DR

This theoretical study proposes a method to generate and detect a single-electron Gaussian wave packet using a quantum-dot pump under strong magnetic fields, advancing solid-state fermion optics.

Contribution

It introduces a realistic approach for producing and identifying single-electron Gaussian states with high precision, utilizing a quantum-dot pump and dynamical potential barriers.

Findings

Electron in a Gaussian state can be generated with a quantum-dot pump.

The emitted state is a Gaussian wave packet when traversal time is much shorter than passage time.

Detection with a dynamical barrier reaches the Heisenberg limit.

Abstract

Generating and detecting a prescribed single-electron state is an important step towards solid-state fermion optics. We propose how to generate an electron in a Gaussian state, using a quantum-dot pump with gigahertz operation and realistic parameters. With the help of a strong magnetic field, the electron occupies a coherent state in the pump, insensitive to the details of nonadiabatic evolution. The state changes during the emission from the pump, governed by competition between the Landauer-Buttiker traversal time and the passage time. When the former is much shorter than the latter, the emitted state is a Gaussian wave packet. The Gaussian packet can be identified by using a dynamical potential barrier, with a resolution reaching the Heisenberg minimal uncertainty $\hbar/2$.