arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2103.16407cond-mat.mes-hallcond-mat.quant-gas
收藏

二维双原子层中高温激子凝聚的证据

Evidence of high-temperature exciton condensation in 2D atomic double layers

Zefang Wang, Daniel A. Rhodes, Kenji Watanabe, Takashi Taniguchi, James C. Hone, Jie Shan, Kin Fai Mak

摘要:

玻色-爱因斯坦凝聚体是玻色子的稀气体的基态,例如冷却到接近绝对零度的原子。由于质量小得多,预期激子(束缚电子-空穴对)在显著更高的温度下凝聚。在这里,我们研究了密度高达10^12 cm-2的MoSe 2/WSe 2原子双层中的电生成层间激子。层间隧穿电流仅取决于激子密度,指示相关的电子-空穴对隧穿。当一个空穴从WSe 2中隧穿并与MoSe 2中的电子复合时,就会产生强的电致发光。我们观察到一个临界阈值依赖的激子密度的EL强度,伴随着一个超泊松光子统计阈值附近,和一个大的EL增强峰值窄在相等的电子-空穴密度。该现象持续高于100 K,这是与预测的临界冷凝温度。我们的研究为二维原子双层中的层间激子凝聚提供了令人信服的证据,并为探索基于凝聚物的光电子学和激子介导的高温超导性开辟了令人兴奋的机会。

英文摘要:

A Bose-Einstein condensate is the ground state of a dilute gas of bosons, such as atoms cooled to temperatures close to absolute zero. With much smaller mass, excitons (bound electron-hole pairs) are expected to condense at significantly higher temperatures. Here we study electrically generated interlayer excitons in MoSe2/WSe2 atomic double layers with density up to 10^12 cm-2. The interlayer tunneling current depends only on exciton density, indicative of correlated electron-hole pair tunneling. Strong electroluminescence (EL) arises when a hole tunnels from WSe2 to recombine with electron in MoSe2. We observe a critical threshold dependence of the EL intensity on exciton density, accompanied by a super-Poissonian photon statistics near threshold, and a large EL enhancement peaked narrowly at equal electron-hole densities. The phenomenon persists above 100 K, which is consistent with the predicted critical condensation temperature. Our study provides compelling evidence for interlayer exciton condensation in two-dimensional atomic double layers and opens up exciting opportunities for exploring condensate-based optoelectronics and exciton-mediated high-temperature superconductivity.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑