09:00 〜 09:30
▲ [7a-A409-1] [JSAP-OSA Joint Symposia 2017 Invited Talk] Ultrastrong Light-Matter Coupling in a High-Q Terahertz Cavity
キーワード：terahertz, ultrastrong light-matter coupling, cavity QED
This talk will describe our recent observation of collective ultrastrong light-matter coupling in an ultrahigh-mobility two-dimensional electron gas (2DEG) in a high-Q terahertz photonic-crystal cavity in a quantizing magnetic field, demonstrating a record-high cooperativity of ~360. The electron cyclotron resonance (CR) peak exhibited splitting into the lower and upper polariton branches with a magnitude that is proportional to the square-root of the 2DEG density, a hallmark of collective vacuum Rabi splitting. Remarkably, the influence of this large splitting can be seen even in a frequency region where the detuning is larger than the resonance frequency itself.