Ph.D. in Science, JST PRESTO, Kyoto University
M. Bamba, X. Li, and J. Kono
Terahertz Strong-Field Physics without a Strong External Terahertz Field
Proceedings of SPIE conference program on Ultrafast Phenomena and Nanophotonics XXIII
arXiv:1901.06749 [cond-mat.mes-hall]
M. Bamba, X. Li, and J. Kono
Vacuum Bloch-Siegert Shift in Cyclotron Resonance
IRMMW-THz2018, International Conference on Infrared, Millimeter, and Terahertz Waves
9-14 Sep 2018 (Nagoya Congress Center, Nagoya, Japan), Th-A2-1a-1
Vacuum Bloch-Siegert shift in Landau polaritons with ultra-high cooperativity
A two-level system resonantly interacting with an a.c. magnetic or electric field constitutes the physical basis of diverse phenomena and technologies. However, Schrödinger’s equation for this seemingly simple system can be solved exactly only under the rotating-wave approximation, which neglects the counter-rotating field component. When the a.c. field is sufficiently strong, this approximation fails, leading to a resonance-frequency shift known as the Bloch–Siegert shift. Here, we report the vacuum Bloch–Siegert shift, which is induced by the ultra-strong coupling of matter with the counter-rotating component of the vacuum fluctuation field in a cavity. Specifically, an ultra-high-mobility two-dimensional electron gas inside a high-Q terahertz cavity in a quantizing magnetic field revealed ultra-narrow Landau polaritons, which exhibited a vacuum Bloch–Siegert shift up to 40 GHz. This shift, clearly distinguishable from the photon-field self-interaction effect, represents a unique manifestation of a strong-field phenomenon without a strong field.
Rice University scientists corral, quantify subtle movement in condensed matter system
A team led by Rice University scientists used a unique combination of techniques to observe, for the first time, a condensed matter phenomenon about which others have only speculated. The research could aid in the development of quantum computers.