Comment on: ''Radiation-Induced ''Zero-Resistance State'' and the Photon Assisted Transport''

TL;DR

This paper discusses the differences between N-shape and S-shape current-voltage characteristics in 2DEG systems, questioning whether N-shape CVC can lead to zero resistance states in magnetic fields, contrasting recent predictions with established knowledge.

Contribution

It clarifies the distinction between N-shape and S-shape CVC behaviors and questions the applicability of N-shape CVC to zero resistance states in magnetic fields.

Findings

N-shape CVC is associated with zero-resistance states in magnetic fields.

S-shape CVC is known to produce zero resistance in zero magnetic field.

The applicability of N-shape CVC to zero-resistance states remains uncertain.

Abstract

Shi and Xie [8] predicted the N-shape current-voltage characteristic $(CVC)$ for a 2DEG in a magnetic field where the zero-resistance state has been observed in recent experiments. However it is known that in the absence of a magnetic field the zero resistance state (zero differential resistance state) is achieved in a system with the S-shape $CVC$. The difference in the behaviour of systems with N- and S-shape $CVC$ was studied more than three decades ago (see for example the review [9] and references therein) and is briefly explained in this Comment. At present it is not clear whether the N-shape $CVC$ may lead to the zero resistance state in a 2DEG in a magnetic field.