Comparison of single-neutral-atom qubit between in bright trap and in dark trap

• 来源期刊: 中国物理B（英文版）
• 关键词: single qubit laser trapping coherence time
• 年，卷（期）: 2019,（2）
• 页码范围: 188-192
• 页数: 5页
• 语种: 英文
• DOI: 10.1088/1674-1056/28/2/023701

摘要

A single neutral atom is one of the most promising candidates to encode a quantum bit (qubit). In a real experiment, a single neutral atom is always confined in a micro-sized far off-resonant optical trap (FORT). There are generally two types of traps: red-detuned trap and blue-detuned trap. We experimentally compare the qubits encoded in "clock states" of single cesium atoms confined separately in either 1064-nm red-detuned (bright) trap or 780-nm blue-detuned (dark) trap: both traps have almost the same trap depth. A longer lifetime of 117 s and a longer coherence time of about 10 ms are achieved in the dark trap. This provides a direct proof of the superiority of the dark trap over the bright trap. The measures to further improve the coherence are discussed.