Year: 2000
Type: preprint
Abstract: It says in the report$^1$ by Wang et al. that a negative group velocity $u=-c/310$ is obtained and that a pulse advancement shift 62-ns is measured. The authors claim that the negative group velocity is associated with superluminal light propagation and that the pulse advancement is not at odds with causality or special relativity. However, it is shown here that their conclusions above are not true. Furthermore, I give some suggestion concerning a re-definition of group-velocity and a new explanation in special relativity of causality.
Source: arXiv (Cornell University)
Author: Zhang, Yuan-Zhong
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1653647338