Picosecond time-resolved two-dimensional ballistic electron transport

TL;DR

This paper reports on measuring picosecond-scale, time-resolved ballistic electron transport in a 2D electron gas, revealing plasma resonances and detailed transit times using advanced electrical and optical techniques.

Contribution

It introduces a novel measurement approach combining picosecond electrical pulses and optoelectronic sampling to resolve ultrafast electron dynamics in 2D systems.

Findings

Ballistic electron transport measured with <5ps resolution

Clear observation of plasma resonances

Transit time longer than simple Fermi velocity estimates

Abstract

Time-resolved transport of ballistic electrons in a two-dimensional electron gas has been measured with a resolution of less than 5ps. This was accomplished by using picosecond electrical pulses to launch electrons from the emitter of a transverse magnetic focusing structure and optoelectronically sampling the collector voltage. Both plasma resonances and the ballistic transport signal are clearly resolved. The transit time appears to be somewhat longer than expected from simple Fermi velocity considerations.