Six-Fold Degenerate Dark States in a Four-Level Atomic System

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2007,（2）
• 页码范围: 428-431
• 页数: 4页
• 语种: 英文

摘要

With all driving fields on Raman resonance, a tripod-type atomic system quickly evolves into a dark state decoupled from the lossy excited level. The dark state depends strongly on field Rabi frequencies, spontaneous decay rates, and the initial atomic population in a complicated way. Analytical results reveal that it is a sixfold degenerate dark state with its three components superposed both coherently and incoherently due to population redistribution from spontaneous emission.